Merge branch 'master' into rename-configuration-to-configure

.github/workflows/changelog.yml

@@ -54,7 +54,7 @@ jobs:
           repositories: >-
             ["jenkins.io"]
       - name: Check out
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           fetch-depth: 0
       - name: Publish jenkins.io changelog draft

.github/workflows/label-lts-prs.yaml

@@ -11,7 +11,7 @@ jobs:
     steps:
       - name: Check if PR targets LTS branch
         if: startsWith(github.event.pull_request.base.ref, 'stable-')
-        uses: actions/github-script@v7
+        uses: actions/github-script@v8
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           script: |

.github/workflows/publish-release-artifact.yml

@@ -15,9 +15,9 @@ jobs:
       is-lts: ${{ steps.set-version.outputs.is-lts }}
       is-rc: ${{ steps.set-version.outputs.is-rc }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Set up JDK 17
-        uses: actions/setup-java@v4
+        uses: actions/setup-java@v5
         with:
           distribution: "temurin"
           java-version: 17
@@ -73,7 +73,7 @@ jobs:
           wget -q https://get.jenkins.io/${REPO}/${PROJECT_VERSION}/${FILE_NAME}
       - name: Upload Release Asset
         id: upload-war
-        uses: softprops/action-gh-release@72f2c25fcb47643c292f7107632f7a47c1df5cd8 # v2.3.2
+        uses: softprops/action-gh-release@6cbd405e2c4e67a21c47fa9e383d020e4e28b836 # v2.3.3
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
@@ -108,7 +108,7 @@ jobs:
       - name: Upload Release Asset
         id: upload-deb
         if: always()
-        uses: softprops/action-gh-release@72f2c25fcb47643c292f7107632f7a47c1df5cd8 # v2.3.2
+        uses: softprops/action-gh-release@6cbd405e2c4e67a21c47fa9e383d020e4e28b836 # v2.3.3
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
@@ -144,7 +144,7 @@ jobs:
       - name: Upload Release Asset
         id: upload-rpm
         if: always()
-        uses: softprops/action-gh-release@72f2c25fcb47643c292f7107632f7a47c1df5cd8 # v2.3.2
+        uses: softprops/action-gh-release@6cbd405e2c4e67a21c47fa9e383d020e4e28b836 # v2.3.3
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
@@ -180,7 +180,7 @@ jobs:
       - name: Upload Release Asset
         id: upload-msi
         if: always()
-        uses: softprops/action-gh-release@72f2c25fcb47643c292f7107632f7a47c1df5cd8 # v2.3.2
+        uses: softprops/action-gh-release@6cbd405e2c4e67a21c47fa9e383d020e4e28b836 # v2.3.3
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
@@ -216,7 +216,7 @@ jobs:
       - name: Upload Release Asset
         id: upload-suse-rpm
         if: always()
-        uses: softprops/action-gh-release@72f2c25fcb47643c292f7107632f7a47c1df5cd8 # v2.3.2
+        uses: softprops/action-gh-release@6cbd405e2c4e67a21c47fa9e383d020e4e28b836 # v2.3.3
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:

.github/workflows/run-since-updater.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ github.repository_owner == 'jenkinsci' }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
       - name: Run update-since-todo.py

.mvn/extensions.xml

@@ -2,6 +2,6 @@
   <extension>
     <groupId>io.jenkins.tools.incrementals</groupId>
     <artifactId>git-changelist-maven-extension</artifactId>
-    <version>1.10</version>
+    <version>1.13</version>
   </extension>
 </extensions>

ath.sh

@@ -6,7 +6,7 @@ set -o xtrace
 cd "$(dirname "$0")"
 
 # https://github.com/jenkinsci/acceptance-test-harness/releases
-export ATH_VERSION=6300.v12732144c83f
+export ATH_VERSION=6361.vcb_036a_7ffb_a_5
 
 if [[ $# -eq 0 ]]; then
 	export JDK=17

bom/pom.xml

@@ -40,8 +40,8 @@ THE SOFTWARE.
   <properties>
     <commons-fileupload2.version>2.0.0-M4</commons-fileupload2.version>
     <groovy.version>2.4.21</groovy.version>
-    <jelly.version>1.1-jenkins-20250616</jelly.version>
-    <stapler.version>1997.v356365fb_929e</stapler.version>
+    <jelly.version>1.1-jenkins-20250731</jelly.version>
+    <stapler.version>2030.v88a_855365981</stapler.version>
   </properties>
 
   <dependencyManagement>
@@ -63,7 +63,7 @@ THE SOFTWARE.
       <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-framework-bom</artifactId>
-        <version>6.2.9</version>
+        <version>6.2.10</version>
         <type>pom</type>
         <scope>import</scope>
       </dependency>
@@ -71,7 +71,7 @@ THE SOFTWARE.
         <!-- https://docs.spring.io/spring-security/reference/6.3/getting-spring-security.html#getting-maven-no-boot -->
         <groupId>org.springframework.security</groupId>
         <artifactId>spring-security-bom</artifactId>
-        <version>6.5.2</version>
+        <version>6.5.3</version>
         <type>pom</type>
         <scope>import</scope>
       </dependency>
@@ -240,7 +240,7 @@ THE SOFTWARE.
       <dependency>
         <groupId>org.jenkins-ci</groupId>
         <artifactId>crypto-util</artifactId>
-        <version>1.10</version>
+        <version>1.11</version>
       </dependency>
       <dependency>
         <groupId>org.jenkins-ci</groupId>
@@ -305,7 +305,7 @@ THE SOFTWARE.
       <dependency>
         <groupId>org.kohsuke.stapler</groupId>
         <artifactId>json-lib</artifactId>
-        <version>2.4-jenkins-8</version>
+        <version>2.4-jenkins-15</version>
       </dependency>
       <dependency>
         <groupId>org.kohsuke.stapler</groupId>

cli/pom.xml

@@ -15,7 +15,7 @@
   <url>https://github.com/jenkinsci/jenkins</url>
 
   <properties>
-    <mina-sshd.version>2.15.0</mina-sshd.version>
+    <mina-sshd.version>2.16.0</mina-sshd.version>
     <!-- Filled in by jacoco-maven-plugin -->
     <jacocoSurefireArgs />
   </properties>
@@ -38,11 +38,6 @@
       <artifactId>commons-io</artifactId>
       <optional>true</optional>
     </dependency>
-    <dependency>
-      <groupId>commons-lang</groupId>
-      <artifactId>commons-lang</artifactId>
-      <optional>true</optional>
-    </dependency>
     <dependency>
       <groupId>org.apache.sshd</groupId>
       <artifactId>sshd-common</artifactId>

cli/src/main/java/hudson/util/QuotedStringTokenizer.java

@@ -36,6 +36,7 @@
 
 package hudson.util;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.NoSuchElementException;
@@ -139,6 +140,9 @@ public class QuotedStringTokenizer
 
     /* ------------------------------------------------------------ */
     @Override
+    @SuppressFBWarnings(
+            value = {"SF_DEAD_STORE_DUE_TO_SWITCH_FALLTHROUGH", "SF_SWITCH_FALLTHROUGH"},
+            justification = "TODO needs triage")
     public boolean hasMoreTokens()
     {
         // Already found a token

core/pom.xml

@@ -117,11 +117,6 @@ THE SOFTWARE.
         </exclusion>
       </exclusions>
     </dependency>
-    <dependency>
-      <groupId>com.infradna.tool</groupId>
-      <artifactId>bridge-method-annotation</artifactId>
-      <version>${bridge-method-injector.version}</version>
-    </dependency>
     <dependency>
       <groupId>com.sun.xml.txw2</groupId>
       <artifactId>txw2</artifactId>
@@ -168,6 +163,11 @@ THE SOFTWARE.
       <groupId>commons-lang</groupId>
       <artifactId>commons-lang</artifactId>
     </dependency>
+    <dependency>
+      <groupId>io.jenkins.tools</groupId>
+      <artifactId>bridge-method-annotation</artifactId>
+      <version>${bridge-method-injector.version}</version>
+    </dependency>
     <dependency>
       <!-- needed by Jelly -->
       <groupId>jakarta.servlet.jsp.jstl</groupId>
@@ -446,11 +446,6 @@ THE SOFTWARE.
       <artifactId>junit-jupiter</artifactId>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>org.junit.vintage</groupId>
-      <artifactId>junit-vintage-engine</artifactId>
-      <scope>test</scope>
-    </dependency>
     <dependency>
       <groupId>org.mockito</groupId>
       <artifactId>mockito-junit-jupiter</artifactId>
@@ -568,7 +563,7 @@ THE SOFTWARE.
         </executions>
       </plugin>
       <plugin>
-        <groupId>com.infradna.tool</groupId>
+        <groupId>io.jenkins.tools</groupId>
         <artifactId>bridge-method-injector</artifactId>
         <executions>
           <execution>

core/src/main/java/hudson/ClassicPluginStrategy.java

@@ -33,6 +33,7 @@ import hudson.PluginWrapper.Dependency;
 import hudson.model.Hudson;
 import hudson.util.CyclicGraphDetector;
 import hudson.util.CyclicGraphDetector.CycleDetectedException;
+import hudson.util.DelegatingClassLoader;
 import hudson.util.IOUtils;
 import hudson.util.MaskingClassLoader;
 import java.io.File;
@@ -559,7 +560,7 @@ public class ClassicPluginStrategy implements PluginStrategy {
     /**
      * Used to load classes from dependency plugins.
      */
-    static final class DependencyClassLoader extends ClassLoader {
+    static final class DependencyClassLoader extends DelegatingClassLoader {
         /**
          * This classloader is created for this plugin. Useful during debugging.
          */
@@ -574,10 +575,6 @@ public class ClassicPluginStrategy implements PluginStrategy {
          */
         private volatile List<PluginWrapper> transitiveDependencies;
 
-        static {
-            registerAsParallelCapable();
-        }
-
         DependencyClassLoader(ClassLoader parent, File archive, List<Dependency> dependencies, PluginManager pluginManager) {
             super("dependency ClassLoader for " + archive.getPath(), parent);
             this._for = archive;

core/src/main/java/hudson/DNSMultiCast.java

@@ -1,15 +0,0 @@
-package hudson;
-
-import org.kohsuke.accmod.Restricted;
-import org.kohsuke.accmod.restrictions.NoExternalUse;
-
-/**
- * @deprecated No longer does anything. Only here to prevent errors from old versions of tools like {@code JenkinsRule}.
- */
-@Deprecated
-@Restricted(NoExternalUse.class)
-public class DNSMultiCast {
-
-    public static boolean disabled = true;
-
-}

core/src/main/java/hudson/PluginManager.java

@@ -58,8 +58,10 @@ import hudson.security.ACL;
 import hudson.security.ACLContext;
 import hudson.security.Permission;
 import hudson.security.PermissionScope;
+import hudson.util.CachingClassLoader;
 import hudson.util.CyclicGraphDetector;
 import hudson.util.CyclicGraphDetector.CycleDetectedException;
+import hudson.util.ExistenceCheckingClassLoader;
 import hudson.util.FormValidation;
 import hudson.util.PersistedList;
 import hudson.util.Retrier;
@@ -106,13 +108,11 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Optional;
 import java.util.ServiceLoader;
 import java.util.Set;
 import java.util.TreeMap;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.Future;
 import java.util.function.Supplier;
@@ -218,6 +218,14 @@ public abstract class PluginManager extends AbstractModelObject implements OnMas
      */
     /* private final */ static int CHECK_UPDATE_ATTEMPTS;
 
+    /**
+     * Class name prefixes to skip in the class loading
+     */
+    private static final String[] CLASS_PREFIXES_TO_SKIP = {
+            "SimpleTemplateScript",  // cf. groovy.text.SimpleTemplateEngine
+            "groovy.tmp.templates.GStringTemplateScript", // Leaks on classLoader in some cases, see JENKINS-75879
+    };
+
     static {
         try {
             // Secure initialization
@@ -2392,43 +2400,50 @@ public abstract class PluginManager extends AbstractModelObject implements OnMas
     /**
      * {@link ClassLoader} that can see all plugins.
      */
-    public static final class UberClassLoader extends ClassLoader {
+    public static final class UberClassLoader extends CachingClassLoader {
         private final List<PluginWrapper> activePlugins;
 
-        /** Cache of loaded, or known to be unloadable, classes. */
-        private final ConcurrentMap<String, Optional<Class<?>>> loaded = new ConcurrentHashMap<>();
-
-        static {
-            registerAsParallelCapable();
-        }
-
+        /**
+         * The servlet container's {@link ClassLoader} (the parent of Jenkins core) is
+         * parallel-capable and maintains its own growing {@link Map} of {@link
+         * ClassLoader#getClassLoadingLock} objects per class name for every load attempt (including
+         * misses), and we cannot override this behavior. Wrap the servlet container {@link
+         * ClassLoader} in {@link ExistenceCheckingClassLoader} to avoid calling {@link
+         * ClassLoader#getParent}'s {@link ClassLoader#loadClass(String, boolean)} at all for misses
+         * by first checking if the resource exists. If the resource does not exist, we immediately
+         * throw {@link ClassNotFoundException}. As a result, the servlet container's {@link
+         * ClassLoader} is never asked to try and fail, and it never creates/retains lock objects
+         * for those misses.
+         */
         public UberClassLoader(List<PluginWrapper> activePlugins) {
-            super("UberClassLoader", PluginManager.class.getClassLoader());
+            super("UberClassLoader", new ExistenceCheckingClassLoader(PluginManager.class.getClassLoader()));
             this.activePlugins = activePlugins;
         }
 
         @Override
-        protected Class<?> findClass(String name) throws ClassNotFoundException {
-            if (name.startsWith("SimpleTemplateScript")) { // cf. groovy.text.SimpleTemplateEngine
-                throw new ClassNotFoundException("ignoring " + name);
+        protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
+            for (String namePrefixToSkip : CLASS_PREFIXES_TO_SKIP) {
+                if (name.startsWith(namePrefixToSkip)) {
+                    throw new ClassNotFoundException("ignoring " + name);
+                }
             }
-            return loaded.computeIfAbsent(name, this::computeValue).orElseThrow(() -> new ClassNotFoundException(name));
+            return super.loadClass(name, resolve);
         }
 
-        private Optional<Class<?>> computeValue(String name) {
+        @Override
+        protected Class<?> findClass(String name) throws ClassNotFoundException {
             for (PluginWrapper p : activePlugins) {
                 try {
                     if (FAST_LOOKUP) {
-                        return Optional.of(ClassLoaderReflectionToolkit.loadClass(p.classLoader, name));
+                        return ClassLoaderReflectionToolkit.loadClass(p.classLoader, name);
                     } else {
-                        return Optional.of(p.classLoader.loadClass(name));
+                        return p.classLoader.loadClass(name);
                     }
                 } catch (ClassNotFoundException e) {
                     // Not found. Try the next class loader.
                 }
             }
-            // Not found in any of the class loaders. Delegate.
-            return Optional.empty();
+            throw new ClassNotFoundException(name);
         }
 
         @Override
@@ -2460,10 +2475,6 @@ public abstract class PluginManager extends AbstractModelObject implements OnMas
             return Collections.enumeration(resources);
         }
 
-        void clearCacheMisses() {
-            loaded.values().removeIf(Optional::isEmpty);
-        }
-
         @Override
         public String toString() {
             // only for debugging purpose

core/src/main/java/hudson/cli/CLICommand.java

@@ -497,7 +497,7 @@ public abstract class CLICommand implements ExtensionPoint, Cloneable {
         this.encoding = encoding;
     }
 
-    protected @NonNull Charset getClientCharset() throws IOException, InterruptedException {
+    public @NonNull Charset getClientCharset() throws IOException, InterruptedException {
         if (encoding != null) {
             return encoding;
         }

core/src/main/java/hudson/diagnosis/ReverseProxySetupMonitor.java

@@ -66,6 +66,11 @@ public class ReverseProxySetupMonitor extends AdministrativeMonitor {
         return true;
     }
 
+    @Override
+    public boolean isActivationFake() {
+        return true;
+    }
+
     @Restricted(DoNotUse.class) // WebOnly
     @RestrictedSince("2.235")
     public HttpResponse doTest(StaplerRequest2 request, @QueryParameter boolean testWithContext) {

core/src/main/java/hudson/model/AbstractItem.java

@@ -129,6 +129,7 @@ public abstract class AbstractItem extends Actionable implements Loadable, Item,
         doSetName(name);
     }
 
+    @NonNull
     @Override
     @Exported(visibility = 999)
     public String getName() {
@@ -470,6 +471,7 @@ public abstract class AbstractItem extends Actionable implements Loadable, Item,
     @Override
     public abstract Collection<? extends Job> getAllJobs();
 
+    @NonNull
     @Override
     @Exported
     public final String getFullName() {

core/src/main/java/hudson/model/AdministrativeMonitor.java

@@ -160,6 +160,11 @@ public abstract class AdministrativeMonitor extends AbstractModelObject implemen
      */
     public abstract boolean isActivated();
 
+    @Restricted(NoExternalUse.class)
+    public boolean isActivationFake() {
+        return false;
+    }
+
     /**
      * Returns true if this monitor is security related.
      *
@@ -186,8 +191,7 @@ public abstract class AdministrativeMonitor extends AbstractModelObject implemen
      * By default {@link Jenkins#ADMINISTER}, but {@link Jenkins#SYSTEM_READ} or {@link Jenkins#MANAGE} are also supported.
      * <p>
      *     Changing this permission check to return {@link Jenkins#SYSTEM_READ} will make the active
-     *     administrative monitor appear on {@code manage.jelly} and on the globally visible
-     *     {@link jenkins.management.AdministrativeMonitorsDecorator} to users without Administer permission.
+     *     administrative monitor appear on {@link ManageJenkinsAction} to users without Administer permission.
      *     {@link #doDisable(StaplerRequest2, StaplerResponse2)} will still always require Administer permission.
      * </p>
      * <p>

core/src/main/java/hudson/model/Computer.java

@@ -625,6 +625,19 @@ public /*transient*/ abstract class Computer extends Actionable implements Acces
         return !isOffline();
     }
 
+    /**
+     * {@inheritDoc}
+     * <p>
+     * Uses {@link #getChannel()} to check the connection.
+     * A connected agent may still be offline for scheduling if marked temporarily offline.
+     * @return {@code true} if the agent is connected, {@code false} otherwise.
+     * @see #isOffline()
+     */
+    @Override
+    public boolean isConnected() {
+        return getChannel() != null;
+    }
+
     /**
      * This method is called to determine whether manual launching of the agent is allowed at this point in time.
      * @return {@code true} if manual launching of the agent is allowed at this point in time.

core/src/main/java/hudson/model/Item.java

@@ -38,7 +38,10 @@ import hudson.security.PermissionScope;
 import hudson.util.Secret;
 import java.io.IOException;
 import java.util.Collection;
+import jenkins.model.FullyNamed;
+import jenkins.model.FullyNamedModelObject;
 import jenkins.model.Jenkins;
+import jenkins.model.Named;
 import jenkins.search.SearchGroup;
 import jenkins.util.SystemProperties;
 import jenkins.util.io.OnMaster;
@@ -73,7 +76,7 @@ import org.kohsuke.stapler.StaplerRequest2;
  * @see Items
  * @see ItemVisitor
  */
-public interface Item extends PersistenceRoot, SearchableModelObject, AccessControlled, OnMaster {
+public interface Item extends PersistenceRoot, FullyNamedModelObject, SearchableModelObject, FullyNamed, Named, AccessControlled, OnMaster {
     /**
      * Gets the parent that contains this item.
      */
@@ -97,6 +100,8 @@ public interface Item extends PersistenceRoot, SearchableModelObject, AccessCont
      *
      * @see #getFullName()
      */
+    @NonNull
+    @Override
     String getName();
 
     /**
@@ -110,6 +115,8 @@ public interface Item extends PersistenceRoot, SearchableModelObject, AccessCont
      *
      * @see jenkins.model.Jenkins#getItemByFullName(String,Class)
      */
+    @NonNull
+    @Override
     String getFullName();
 
     /**
@@ -127,13 +134,6 @@ public interface Item extends PersistenceRoot, SearchableModelObject, AccessCont
     @Override
     String getDisplayName();
 
-    /**
-     * Works like {@link #getDisplayName()} but return
-     * the full path that includes all the display names
-     * of the ancestors.
-     */
-    String getFullDisplayName();
-
     /**
      * Gets the relative name to this item from the specified group.
      *

core/src/main/java/hudson/model/ItemGroup.java

@@ -33,6 +33,8 @@ import java.util.List;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
+import jenkins.model.FullyNamed;
+import jenkins.model.FullyNamedModelObject;
 import org.springframework.security.access.AccessDeniedException;
 
 /**
@@ -41,19 +43,7 @@ import org.springframework.security.access.AccessDeniedException;
  * @author Kohsuke Kawaguchi
  * @see ItemGroupMixIn
  */
-public interface ItemGroup<T extends Item> extends PersistenceRoot, ModelObject {
-    /**
-     * Gets the full name of this {@link ItemGroup}.
-     *
-     * @see Item#getFullName()
-     */
-    String getFullName();
-
-    /**
-     * @see Item#getFullDisplayName()
-     */
-    String getFullDisplayName();
-
+public interface ItemGroup<T extends Item> extends FullyNamed, FullyNamedModelObject, PersistenceRoot {
     /**
      * Gets all the items in this collection in a read-only view.
      */

core/src/main/java/hudson/model/Job.java

@@ -77,6 +77,7 @@ import java.awt.Paint;
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Calendar;
 import java.util.Collection;
@@ -210,9 +211,11 @@ public abstract class Job<JobT extends Job<JobT, RunT>, RunT extends Run<JobT, R
         // This code can be deleted after several Jenkins releases,
         // when it is likely that everyone is running a version equal or higher to this version.
         var buildDirPath = getBuildDir().toPath();
-        if (Files.deleteIfExists(buildDirPath.resolve("legacyIds"))) {
+        Path legacyIds = buildDirPath.resolve("legacyIds");
+        if (Files.exists(legacyIds)) {
             LOGGER.info("Deleting legacyIds file in " + buildDirPath + ". See https://issues.jenkins"
                         + ".io/browse/JENKINS-75465 for more information.");
+            Files.delete(legacyIds);
         }
 
         TextFile f = getNextBuildNumberFile();

core/src/main/java/hudson/model/ManageJenkinsAction.java

@@ -26,11 +26,11 @@ package hudson.model;
 
 import hudson.Extension;
 import hudson.Util;
+import hudson.util.HudsonIsLoading;
+import hudson.util.HudsonIsRestarting;
 import java.io.IOException;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Optional;
-import jenkins.management.AdministrativeMonitorsDecorator;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import jenkins.management.Badge;
 import jenkins.model.Jenkins;
 import jenkins.model.ModelObjectWithContextMenu;
@@ -50,6 +50,9 @@ import org.kohsuke.stapler.StaplerResponse2;
  */
 @Extension(ordinal = 998) @Symbol("manageJenkins")
 public class ManageJenkinsAction implements RootAction, StaplerFallback, ModelObjectWithContextMenu {
+
+    private static final Logger LOGGER = Logger.getLogger(ManageJenkinsAction.class.getName());
+
     @Override
     public String getIconFileName() {
         if (Jenkins.get().hasAnyPermission(Jenkins.MANAGE, Jenkins.SYSTEM_READ))
@@ -98,28 +101,36 @@ public class ManageJenkinsAction implements RootAction, StaplerFallback, ModelOb
         menu.add("manage/" + url, icon, iconXml, text, post, requiresConfirmation, badge, message);
     }
 
+    /** Unlike {@link Jenkins#getActiveAdministrativeMonitors} this checks for activation lazily. */
     @Override
     public Badge getBadge() {
-        Jenkins jenkins = Jenkins.get();
-        AdministrativeMonitorsDecorator decorator = jenkins.getExtensionList(PageDecorator.class)
-                .get(AdministrativeMonitorsDecorator.class);
-
-        if (decorator == null) {
+        if (!(AdministrativeMonitor.hasPermissionToDisplay())) {
             return null;
         }
 
-        Collection<AdministrativeMonitor> activeAdministrativeMonitors = Optional.ofNullable(decorator.getMonitorsToDisplay()).orElse(Collections.emptyList());
-        boolean anySecurity = activeAdministrativeMonitors.stream().anyMatch(AdministrativeMonitor::isSecurity);
-
-        if (activeAdministrativeMonitors.isEmpty()) {
+        var app = Jenkins.get().getServletContext().getAttribute("app");
+        if (app instanceof HudsonIsLoading || app instanceof HudsonIsRestarting) {
             return null;
         }
 
-        int size = activeAdministrativeMonitors.size();
-        String tooltip = size > 1 ? Messages.ManageJenkinsAction_notifications(size) : Messages.ManageJenkinsAction_notification(size);
-
-        return new Badge(String.valueOf(size),
-                tooltip,
-                anySecurity ? Badge.Severity.DANGER : Badge.Severity.WARNING);
+        if (Jenkins.get().administrativeMonitors.stream().anyMatch(m -> m.isSecurity() && isActive(m))) {
+            return new Badge("1+", Messages.ManageJenkinsAction_notifications(),
+                    Badge.Severity.DANGER);
+        } else if (Jenkins.get().administrativeMonitors.stream().anyMatch(m -> !m.isSecurity() && isActive(m))) {
+            return new Badge("1+", Messages.ManageJenkinsAction_notifications(),
+                    Badge.Severity.WARNING);
+        } else {
+            return null;
+        }
     }
+
+    private static boolean isActive(AdministrativeMonitor m) {
+        try {
+            return !m.isActivationFake() && m.hasRequiredPermission() && m.isEnabled() && m.isActivated();
+        } catch (Throwable x) {
+            LOGGER.log(Level.WARNING, null, x);
+            return false;
+        }
+    }
+
 }

core/src/main/java/hudson/model/Queue.java

@@ -109,6 +109,8 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.stream.Collectors;
 import jenkins.console.WithConsoleUrl;
+import jenkins.model.FullyNamed;
+import jenkins.model.FullyNamedModelObject;
 import jenkins.model.Jenkins;
 import jenkins.model.queue.AsynchronousExecution;
 import jenkins.model.queue.CompositeCauseOfBlockage;
@@ -1882,7 +1884,7 @@ public class Queue extends ResourceController implements Saveable {
      * design, a {@link Task} must have at least one sub-task.)
      * Most of the time, the primary subtask is the only sub task.
      */
-    public interface Task extends ModelObject, SubTask {
+    public interface Task extends FullyNamedModelObject, SubTask {
         /**
          * Returns true if the execution should be blocked
          * for temporary reasons.
@@ -1928,21 +1930,22 @@ public class Queue extends ResourceController implements Saveable {
          */
         String getName();
 
-        /**
-         * @see hudson.model.Item#getFullDisplayName()
-         */
-        String getFullDisplayName();
-
         /**
          * Returns task-specific key which is used by the {@link LoadBalancer} to choose one particular executor
          * amongst all the free executors on all possibly suitable nodes.
          * NOTE: To be able to re-use the same node during the next run this key should not change from one run to
          * another. You probably want to compute that key based on the job's name.
          *
-         * @return by default: {@link #getFullDisplayName()}
+         * @return by default: {@link FullyNamed#getFullName()} if implements {@link FullyNamed} or {@link #getFullDisplayName()} otherwise.
          * @see hudson.model.LoadBalancer
          */
-        default String getAffinityKey() { return getFullDisplayName(); }
+        default String getAffinityKey() {
+            if (this instanceof FullyNamed fullyNamed) {
+                return fullyNamed.getFullName();
+            } else {
+                return getFullDisplayName();
+            }
+        }
 
         /**
          * Checks the permission to see if the current user can abort this executable.

core/src/main/java/hudson/model/ResourceActivity.java

@@ -29,7 +29,7 @@ package hudson.model;
  *
  * @author Kohsuke Kawaguchi
  */
-public interface ResourceActivity {
+public interface ResourceActivity extends ModelObject {
     /**
      * Gets the list of {@link Resource}s that this task requires.
      * Used to make sure no two conflicting tasks run concurrently.
@@ -47,9 +47,4 @@ public interface ResourceActivity {
     default ResourceList getResourceList() {
         return ResourceList.EMPTY;
     }
-
-    /**
-     * Used for rendering HTML.
-     */
-    String getDisplayName();
 }

core/src/main/java/hudson/model/RunMap.java

@@ -95,7 +95,7 @@ public final class RunMap<R extends Run<?, R>> extends AbstractLazyLoadRunMap<R>
      *      Used to create new instance of {@link Run}.
      * @since 2.451
      */
-    public RunMap(@NonNull Job<?, ?> job, Constructor cons) {
+    public RunMap(@NonNull Job<?, ?> job, Constructor<R> cons) {
         this.job = Objects.requireNonNull(job);
         this.cons = cons;
         initBaseDir(job.getBuildDir());
@@ -105,7 +105,7 @@ public final class RunMap<R extends Run<?, R>> extends AbstractLazyLoadRunMap<R>
      * @deprecated Use {@link #RunMap(Job, Constructor)}.
      */
     @Deprecated
-    public RunMap(File baseDir, Constructor cons) {
+    public RunMap(File baseDir, Constructor<R> cons) {
         job = null;
         this.cons = cons;
         initBaseDir(baseDir);
@@ -187,6 +187,8 @@ public final class RunMap<R extends Run<?, R>> extends AbstractLazyLoadRunMap<R>
      */
     public interface Constructor<R extends Run<?, R>> {
         R create(File dir) throws IOException;
+
+        Class<R> getBuildClass();
     }
 
     @Override
@@ -201,7 +203,7 @@ public final class RunMap<R extends Run<?, R>> extends AbstractLazyLoadRunMap<R>
 
     /**
      * Add a <em>new</em> build to the map.
-     * Do not use when loading existing builds (use {@link #put(Integer, Object)}).
+     * Do not use when loading existing builds (use {@link #putAll(Map)}).
      */
     @Override
     public R put(R r) {
@@ -298,6 +300,11 @@ public final class RunMap<R extends Run<?, R>> extends AbstractLazyLoadRunMap<R>
         return null;
     }
 
+    @Override
+    protected Class<R> getBuildClass() {
+        return cons.getBuildClass();
+    }
+
     /**
      * Backward compatibility method that notifies {@link RunMap} of who the owner is.
      *

core/src/main/java/hudson/model/User.java

@@ -52,12 +52,15 @@ import jakarta.servlet.ServletException;
 import jakarta.servlet.http.HttpServletResponse;
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.StandardCopyOption;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
@@ -67,12 +70,14 @@ import java.util.concurrent.ExecutionException;
 import java.util.function.Predicate;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import java.util.regex.Pattern;
 import jenkins.model.IdStrategy;
 import jenkins.model.Jenkins;
 import jenkins.model.Loadable;
 import jenkins.model.ModelObjectWithContextMenu;
 import jenkins.scm.RunWithSCM;
 import jenkins.search.SearchGroup;
+import jenkins.security.HMACConfidentialKey;
 import jenkins.security.ImpersonatingUserDetailsService2;
 import jenkins.security.LastGrantedAuthoritiesProperty;
 import jenkins.security.UserDetailsCache;
@@ -174,7 +179,7 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
 
     @SuppressFBWarnings(value = "SS_SHOULD_BE_STATIC", justification = "Reserved for future use")
     private final int version = 10; // Not currently used, but it may be helpful in the future to store a version.
-    private String id;
+    String id;
     private volatile String fullName;
     private volatile String description;
 
@@ -185,6 +190,8 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
         XSTREAM.alias("user", User.class);
     }
 
+    private User() {}
+
     private User(String id, String fullName) {
         this.id = id;
         this.fullName = fullName;
@@ -199,6 +206,10 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
     private void load(String userId) {
         clearExistingProperties();
         loadFromUserConfigFile(userId);
+        fixUpAfterLoad();
+    }
+
+    private void fixUpAfterLoad() {
         removeNullsThatFailedToLoad();
         allocateDefaultPropertyInstancesAsNeeded();
         setUserToProperties();
@@ -225,9 +236,10 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
     }
 
     private void loadFromUserConfigFile(String userId) {
+        AllUsers.getInstance().migrateUserIdMapper();
         XmlFile config = getConfigFile();
         try {
-            if (config != null && config.exists()) {
+            if (config.exists()) {
                 config.unmarshal(this);
                 this.id = userId;
             }
@@ -241,8 +253,7 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
     }
 
     private XmlFile getConfigFile() {
-        File existingUserFolder = getExistingUserFolder();
-        return existingUserFolder == null ? null : new XmlFile(XSTREAM, new File(existingUserFolder, CONFIG_XML));
+        return new XmlFile(XSTREAM, new File(getUserFolderFor(id), CONFIG_XML));
     }
 
     /**
@@ -571,10 +582,10 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
      */
     private static @Nullable User getOrCreateById(@NonNull String id, @NonNull String fullName, boolean create) {
         User u = AllUsers.get(id);
-        if (u == null && (create || UserIdMapper.getInstance().isMapped(id))) {
+        if (u == null && create) {
             u = new User(id, fullName);
             AllUsers.put(id, u);
-            if (!id.equals(fullName) && !UserIdMapper.getInstance().isMapped(id)) {
+            if (!id.equals(fullName)) {
                 try {
                     u.save();
                 } catch (IOException x) {
@@ -691,7 +702,6 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
      */
     @Restricted(Beta.class)
     public static void reload() throws IOException {
-        UserIdMapper.getInstance().reload();
         AllUsers.reload();
     }
 
@@ -708,6 +718,32 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
             or greater issues in the realm change, could affect currently logged
             in users and even the user making the change. */
         try {
+            var subdirectories = getRootDir().listFiles();
+            if (subdirectories != null) {
+                for (var oldDirectory : subdirectories) {
+                    var dirName = oldDirectory.getName();
+                    if (!HASHED_DIRNAMES.matcher(dirName).matches()) {
+                        continue;
+                    }
+                    var xml = new XmlFile(XSTREAM, new File(oldDirectory, CONFIG_XML));
+                    if (!xml.exists()) {
+                        continue;
+                    }
+                    try {
+                        var user = (User) xml.read();
+                        if (user.id == null) {
+                            continue;
+                        }
+                        var newDirectory = getUserFolderFor(user.id);
+                        if (!oldDirectory.equals(newDirectory)) {
+                            Files.move(oldDirectory.toPath(), newDirectory.toPath(), StandardCopyOption.REPLACE_EXISTING);
+                            LOGGER.info(() -> "migrated " + oldDirectory + " to " + newDirectory);
+                        }
+                    } catch (Exception x) {
+                        LOGGER.log(Level.WARNING, "failed to migrate " + xml, x);
+                    }
+                }
+            }
             reload();
         } catch (IOException e) {
             LOGGER.log(Level.SEVERE, "Failed to perform rekey operation.", e);
@@ -777,17 +813,9 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
         if (ExtensionList.lookup(AllUsers.class).isEmpty()) {
             return;
         }
-        UserIdMapper.getInstance().clear();
         AllUsers.clear();
     }
 
-    private static File getConfigFileFor(String id) {
-        return new File(getUserFolderFor(id), "config.xml");
-    }
-
-    private static File getUserFolderFor(String id) {
-        return new File(getRootDir(), idStrategy().filenameOf(id));
-    }
     /**
      * Returns the folder that store all the user information.
      * Useful for plugins to save a user-specific file aside the config.xml.
@@ -799,11 +827,8 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
      */
 
     public @CheckForNull File getUserFolder() {
-        return getExistingUserFolder();
-    }
-
-    private @CheckForNull File getExistingUserFolder() {
-        return UserIdMapper.getInstance().getDirectory(id);
+        var d = getUserFolderFor(id);
+        return d.isDirectory() ? d : null;
     }
 
     /**
@@ -813,6 +838,21 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
         return new File(Jenkins.get().getRootDir(), "users");
     }
 
+    private static final int PREFIX_MAX = 14;
+    private static final Pattern DISALLOWED_PREFIX_CHARS = Pattern.compile("[^A-Za-z0-9]");
+    static final Pattern HASHED_DIRNAMES = Pattern.compile("[a-z0-9]{0," + PREFIX_MAX + "}_[a-f0-9]{64}");
+    private static final HMACConfidentialKey DIRNAMES = new HMACConfidentialKey(User.class, "DIRNAMES");
+
+    private static String getUserFolderNameFor(String id) {
+        var fullPrefix = DISALLOWED_PREFIX_CHARS.matcher(id).replaceAll("").toLowerCase(Locale.ROOT);
+        return (fullPrefix.length() > PREFIX_MAX ? fullPrefix.substring(0, PREFIX_MAX) : fullPrefix) + '_' + DIRNAMES.mac(idStrategy().keyFor(id));
+    }
+
+    @SuppressFBWarnings(value = "PATH_TRAVERSAL_IN", justification = "sanitized")
+    static File getUserFolderFor(String id) {
+        return new File(getRootDir(), getUserFolderNameFor(id));
+    }
+
     /**
      * Is the ID allowed? Some are prohibited for security reasons. See SECURITY-166.
      * <p>
@@ -852,19 +892,11 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
         if (BulkChange.contains(this)) {
             return;
         }
-        XmlFile xmlFile = new XmlFile(XSTREAM, constructUserConfigFile());
+        XmlFile xmlFile = getConfigFile();
         xmlFile.write(this);
         SaveableListener.fireOnChange(this, xmlFile);
     }
 
-    private File constructUserConfigFile() throws IOException {
-        return new File(putUserFolderIfAbsent(), CONFIG_XML);
-    }
-
-    private File putUserFolderIfAbsent() throws IOException {
-        return UserIdMapper.getInstance().putIfAbsent(id, true);
-    }
-
     /**
      * Deletes the data directory and removes this user from Hudson.
      *
@@ -872,19 +904,11 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
      */
     public void delete() throws IOException {
         String idKey = idStrategy().keyFor(id);
-        File existingUserFolder = getExistingUserFolder();
-        UserIdMapper.getInstance().remove(id);
         AllUsers.remove(id);
-        deleteExistingUserFolder(existingUserFolder);
+        Util.deleteRecursive(getUserFolderFor(id));
         UserDetailsCache.get().invalidate(idKey);
     }
 
-    private void deleteExistingUserFolder(File existingUserFolder) throws IOException {
-        if (existingUserFolder != null && existingUserFolder.exists()) {
-            Util.deleteRecursive(existingUserFolder);
-        }
-    }
-
     /**
      * Exposed remote API.
      */
@@ -947,7 +971,7 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
     public boolean canDelete() {
         final IdStrategy strategy = idStrategy();
         return hasPermission(Jenkins.ADMINISTER) && !strategy.equals(id, Jenkins.getAuthentication2().getName())
-                && UserIdMapper.getInstance().isMapped(id);
+                && getUserFolder() != null;
     }
 
     /**
@@ -1074,16 +1098,70 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
     @Restricted(NoExternalUse.class)
     public static final class AllUsers {
 
+        private boolean migratedUserIdMapper;
         private final ConcurrentMap<String, User> byName = new ConcurrentHashMap<>();
 
-        @Initializer(after = InitMilestone.JOB_CONFIG_ADAPTED)
-        public static void scanAll() {
-            for (String userId : UserIdMapper.getInstance().getConvertedUserIds()) {
-                User user = new User(userId, userId);
-                getInstance().byName.putIfAbsent(idStrategy().keyFor(userId), user);
+        @SuppressWarnings("deprecation")
+        synchronized void migrateUserIdMapper() {
+            if (!migratedUserIdMapper) {
+                try {
+                    UserIdMapper.migrate();
+                } catch (IOException x) {
+                    LOGGER.log(Level.WARNING, null, x);
+                }
+                migratedUserIdMapper = true;
             }
         }
 
+        @Initializer(after = InitMilestone.JOB_CONFIG_ADAPTED)
+        public static void scanAll() throws IOException {
+            DIRNAMES.createMac(); // force the key to be saved during startup
+            var instance = getInstance();
+            instance.migrateUserIdMapper();
+            var subdirectories = getRootDir().listFiles();
+            if (subdirectories == null) {
+                return;
+            }
+            var byName = instance.byName;
+            var idStrategy = idStrategy();
+            for (var dir : subdirectories) {
+                var dirName = dir.getName();
+                if (!HASHED_DIRNAMES.matcher(dirName).matches()) {
+                    LOGGER.fine(() -> "ignoring unrecognized dir " + dir);
+                    continue;
+                }
+                var xml = new XmlFile(XSTREAM, new File(dir, CONFIG_XML));
+                if (!xml.exists()) {
+                    LOGGER.fine(() -> "ignoring dir " + dir + " with no " + CONFIG_XML);
+                    continue;
+                }
+                var user = new User();
+                try {
+                    xml.unmarshal(user);
+                } catch (Exception x) {
+                    LOGGER.log(Level.WARNING, "failed to load " + xml, x);
+                    continue;
+                }
+                if (user.id == null) {
+                    LOGGER.warning(() -> "ignoring " + xml + " with no <id>");
+                    continue;
+                }
+                var expectedFolderName = getUserFolderNameFor(user.id);
+                if (!dirName.equals(expectedFolderName)) {
+                    LOGGER.warning(() -> "ignoring " + xml + " with <id> " + user.id + " expected to be in " + expectedFolderName);
+                    continue;
+                }
+                user.fixUpAfterLoad();
+                var old = byName.put(idStrategy.keyFor(user.id), user);
+                if (old != null) {
+                    LOGGER.warning(() -> "entry for " + user.id + " in " + dir + " duplicates one seen earlier for " + old.id);
+                } else {
+                    LOGGER.fine(() -> "successfully loaded " + user.id + " from " + xml);
+                }
+            }
+            LOGGER.fine(() -> "loaded " + byName.size() + " entries");
+        }
+
         /**
          * Keyed by {@link User#id}. This map is used to ensure
          * singleton-per-id semantics of {@link User} objects.
@@ -1094,7 +1172,7 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
             return ExtensionList.lookupSingleton(AllUsers.class);
         }
 
-        private static void reload() {
+        private static void reload() throws IOException {
             getInstance().byName.clear();
             UserDetailsCache.get().invalidateAll();
             scanAll();
@@ -1252,7 +1330,7 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
                         UserDetails userDetails = UserDetailsCache.get().loadUserByUsername(idOrFullName);
                         return userDetails.getUsername();
                     } catch (UsernameNotFoundException x) {
-                        LOGGER.log(Level.FINE, "not sure whether " + idOrFullName + " is a valid username or not", x);
+                        LOGGER.log(Level.FINER, "not sure whether " + idOrFullName + " is a valid username or not", x);
                     } catch (ExecutionException x) {
                         LOGGER.log(Level.FINE, "could not look up " + idOrFullName, x);
                     } finally {

core/src/main/java/hudson/model/UserIdMapper.java

@@ -24,179 +24,90 @@
 
 package hudson.model;
 
-import edu.umd.cs.findbugs.annotations.CheckForNull;
-import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
-import hudson.Extension;
-import hudson.ExtensionList;
-import hudson.Util;
 import hudson.XmlFile;
-import hudson.init.InitMilestone;
-import hudson.init.Initializer;
 import hudson.util.XStream2;
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
-import java.nio.file.NoSuchFileException;
-import java.nio.file.Path;
-import java.util.Collections;
+import java.nio.file.StandardCopyOption;
 import java.util.Map;
-import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import java.util.regex.Pattern;
 import jenkins.model.IdStrategy;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
 
+/**
+ * @deprecated Formerly used to track which directory held each user configuration.
+ *             Now that is deterministic based on a hash of {@link IdStrategy#keyFor}.
+ */
+@Deprecated
 @Restricted(NoExternalUse.class)
-@Extension
 public class UserIdMapper {
 
     private static final XStream2 XSTREAM = new XStream2();
-    static final String MAPPING_FILE = "users.xml";
     private static final Logger LOGGER = Logger.getLogger(UserIdMapper.class.getName());
-    private static final int PREFIX_MAX = 15;
-    private static final Pattern PREFIX_PATTERN = Pattern.compile("[^A-Za-z0-9]");
-    @SuppressFBWarnings(value = "SS_SHOULD_BE_STATIC", justification = "Reserved for future use")
-    private final int version = 1; // Not currently used, but it may be helpful in the future to store a version.
 
-    private transient File usersDirectory;
+    // contrary to the name, the keys were actually IdStrategy.keyFor, not necessarily ids
     private Map<String, String> idToDirectoryNameMap = new ConcurrentHashMap<>();
 
-    static UserIdMapper getInstance() {
-        return ExtensionList.lookupSingleton(UserIdMapper.class);
+    private UserIdMapper() {
     }
 
-    public UserIdMapper() {
-    }
-
-    @Initializer(after = InitMilestone.PLUGINS_STARTED, before = InitMilestone.JOB_LOADED)
-    public File init() throws IOException {
-        usersDirectory = createUsersDirectoryAsNeeded();
-        load();
-        return usersDirectory;
-    }
-
-    @CheckForNull File getDirectory(String userId) {
-        String directoryName = idToDirectoryNameMap.get(getIdStrategy().keyFor(userId));
-        return directoryName == null ? null : new File(usersDirectory, directoryName);
-    }
-
-    File putIfAbsent(String userId, boolean saveToDisk) throws IOException {
-        String idKey = getIdStrategy().keyFor(userId);
-        String directoryName = idToDirectoryNameMap.get(idKey);
-        File directory = null;
-        if (directoryName == null) {
-            synchronized (this) {
-                directoryName = idToDirectoryNameMap.get(idKey);
-                if (directoryName == null) {
-                    directory = createDirectoryForNewUser(userId);
-                    directoryName = directory.getName();
-                    idToDirectoryNameMap.put(idKey, directoryName);
-                    if (saveToDisk) {
-                        save();
+    @SuppressWarnings("deprecation")
+    static void migrate() throws IOException {
+        var idStrategy = User.idStrategy();
+        var usersDirectory = User.getRootDir();
+        var data = new UserIdMapper();
+        var mapperXml = new XmlFile(XSTREAM, new File(usersDirectory, "users.xml"));
+        if (mapperXml.exists()) { // need to migrate
+            // Load it, and trust ids it defines over <id>…</id> in users/…/config.xml which UserIdMigrator neglected to resave.
+            LOGGER.info(() -> "migrating " + mapperXml);
+            mapperXml.unmarshal(data);
+            for (var entry : data.idToDirectoryNameMap.entrySet()) {
+                var idKey = entry.getKey();
+                var directoryName = entry.getValue();
+                try {
+                    var oldDirectory = new File(usersDirectory, directoryName);
+                    var userXml = new XmlFile(User.XSTREAM, new File(oldDirectory, User.CONFIG_XML));
+                    var user = (User) userXml.read();
+                    if (user.id == null || !idKey.equals(idStrategy.keyFor(user.id))) {
+                        user.id = idKey; // not quite right but hoping for the best
+                        userXml.write(user);
                     }
+                    var newDirectory = User.getUserFolderFor(user.id);
+                    Files.move(oldDirectory.toPath(), newDirectory.toPath(), StandardCopyOption.REPLACE_EXISTING);
+                    LOGGER.info(() -> "migrated " + oldDirectory + " to " + newDirectory);
+                } catch (Exception x) {
+                    LOGGER.log(Level.WARNING, "failed to migrate " + entry, x);
                 }
             }
+            mapperXml.delete();
         }
-        return directory == null ? new File(usersDirectory, directoryName) : directory;
-    }
-
-    boolean isMapped(String userId) {
-        return idToDirectoryNameMap.containsKey(getIdStrategy().keyFor(userId));
-    }
-
-    Set<String> getConvertedUserIds() {
-        return Collections.unmodifiableSet(idToDirectoryNameMap.keySet());
-    }
-
-    void remove(String userId) throws IOException {
-        idToDirectoryNameMap.remove(getIdStrategy().keyFor(userId));
-        save();
-    }
-
-    void clear() {
-        idToDirectoryNameMap.clear();
-    }
-
-    void reload() throws IOException {
-        clear();
-        load();
-    }
-
-    protected IdStrategy getIdStrategy() {
-        return User.idStrategy();
-    }
-
-    protected File getUsersDirectory() {
-        return User.getRootDir();
-    }
-
-    private XmlFile getXmlConfigFile() {
-        File file = getConfigFile(usersDirectory);
-        return new XmlFile(XSTREAM, file);
-    }
-
-    static File getConfigFile(File usersDirectory) {
-        return new File(usersDirectory, MAPPING_FILE);
-    }
-
-    private File createDirectoryForNewUser(String userId) throws IOException {
-        try {
-            Path tempDirectory = Files.createTempDirectory(Util.fileToPath(usersDirectory), generatePrefix(userId));
-            return tempDirectory.toFile();
-        } catch (IOException e) {
-            LOGGER.log(Level.SEVERE, "Error creating directory for user: " + userId, e);
-            throw e;
-        }
-    }
-
-    private String generatePrefix(String userId) {
-        String fullPrefix = PREFIX_PATTERN.matcher(userId).replaceAll("");
-        return fullPrefix.length() > PREFIX_MAX - 1 ? fullPrefix.substring(0, PREFIX_MAX - 1) + '_' : fullPrefix + '_';
-    }
-
-    private File createUsersDirectoryAsNeeded() throws IOException {
-        File usersDirectory = getUsersDirectory();
-        if (!usersDirectory.exists()) {
-            try {
-                Files.createDirectory(usersDirectory.toPath());
-            } catch (IOException e) {
-                LOGGER.log(Level.SEVERE, "Unable to create users directory: " + usersDirectory, e);
-                throw e;
-            }
-        }
-        return usersDirectory;
-    }
-
-    synchronized void save() throws IOException {
-        try {
-            getXmlConfigFile().write(this);
-        } catch (IOException ioe) {
-            LOGGER.log(Level.WARNING, "Error saving userId mapping file.", ioe);
-            throw ioe;
-        }
-    }
-
-    private void load() throws IOException {
-        UserIdMigrator migrator = new UserIdMigrator(usersDirectory, getIdStrategy());
-        if (migrator.needsMigration()) {
-            try {
-                migrator.migrateUsers(this);
-            } catch (IOException ioe) {
-                LOGGER.log(Level.SEVERE, "Error migrating users.", ioe);
-                throw ioe;
-            }
-        } else {
-            XmlFile config = getXmlConfigFile();
-            try {
-                config.unmarshal(this);
-            } catch (NoSuchFileException e) {
-                LOGGER.log(Level.FINE, "User id mapping file does not exist. It will be created when a user is saved.");
-            } catch (IOException e) {
-                LOGGER.log(Level.WARNING, "Failed to load " + config, e);
-                throw e;
+        // Also look for any remaining user dirs, such as those predating even UserIdMapper, or PresetData or incomplete @LocalData.
+        var subdirectories = usersDirectory.listFiles();
+        if (subdirectories != null) {
+            for (var oldDirectory : subdirectories) {
+                if (!User.HASHED_DIRNAMES.matcher(oldDirectory.getName()).matches()) {
+                    var userXml = new XmlFile(User.XSTREAM, new File(oldDirectory, User.CONFIG_XML));
+                    if (userXml.exists()) {
+                        try {
+                            var user = (User) userXml.read();
+                            var id = user.id;
+                            if (id == null) {
+                                id = idStrategy.idFromFilename(oldDirectory.getName());
+                                user.id = id;
+                                userXml.write(user);
+                            }
+                            var newDirectory = User.getUserFolderFor(id);
+                            Files.move(oldDirectory.toPath(), newDirectory.toPath(), StandardCopyOption.REPLACE_EXISTING);
+                            LOGGER.info(() -> "migrated " + oldDirectory + " to " + newDirectory);
+                        } catch (Exception x) {
+                            LOGGER.log(Level.WARNING, "failed to migrate " + oldDirectory, x);
+                        }
+                    }
+                }
             }
         }
     }

core/src/main/java/hudson/model/UserIdMigrator.java

@@ -1,103 +0,0 @@
-/*
- * The MIT License
- *
- * Copyright (c) 2018 CloudBees, Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-package hudson.model;
-
-import java.io.File;
-import java.io.IOException;
-import java.nio.file.Files;
-import java.nio.file.StandardCopyOption;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import jenkins.model.IdStrategy;
-import org.kohsuke.accmod.Restricted;
-import org.kohsuke.accmod.restrictions.NoExternalUse;
-
-@Restricted(NoExternalUse.class)
-class UserIdMigrator {
-
-    private static final Logger LOGGER = Logger.getLogger(UserIdMigrator.class.getName());
-    private static final String EMPTY_USERNAME_DIRECTORY_NAME = "emptyUsername";
-
-    private final File usersDirectory;
-    private final IdStrategy idStrategy;
-
-    UserIdMigrator(File usersDirectory, IdStrategy idStrategy) {
-        this.usersDirectory = usersDirectory;
-        this.idStrategy = idStrategy;
-    }
-
-    boolean needsMigration() {
-        File mappingFile = UserIdMapper.getConfigFile(usersDirectory);
-        if (mappingFile.exists() && mappingFile.isFile()) {
-            LOGGER.finest("User mapping file already exists. No migration needed.");
-            return false;
-        }
-        File[] userDirectories = listUserDirectories();
-        return userDirectories != null && userDirectories.length > 0;
-    }
-
-    private File[] listUserDirectories() {
-        return usersDirectory.listFiles(file -> file.isDirectory() && new File(file, User.CONFIG_XML).exists());
-    }
-
-    Map<String, File> scanExistingUsers() throws IOException {
-        Map<String, File> users = new HashMap<>();
-        File[] userDirectories = listUserDirectories();
-        if (userDirectories != null) {
-            for (File directory : userDirectories) {
-                String userId = idStrategy.idFromFilename(directory.getName());
-                users.put(userId, directory);
-            }
-        }
-        addEmptyUsernameIfExists(users);
-        return users;
-    }
-
-    private void addEmptyUsernameIfExists(Map<String, File> users) throws IOException {
-        File emptyUsernameConfigFile = new File(usersDirectory, User.CONFIG_XML);
-        if (emptyUsernameConfigFile.exists()) {
-            File newEmptyUsernameDirectory = new File(usersDirectory, EMPTY_USERNAME_DIRECTORY_NAME);
-            Files.createDirectory(newEmptyUsernameDirectory.toPath());
-            File newEmptyUsernameConfigFile = new File(newEmptyUsernameDirectory, User.CONFIG_XML);
-            Files.move(emptyUsernameConfigFile.toPath(), newEmptyUsernameConfigFile.toPath());
-            users.put("", newEmptyUsernameDirectory);
-        }
-    }
-
-    void migrateUsers(UserIdMapper mapper) throws IOException {
-        LOGGER.fine("Beginning migration of users to userId mapping.");
-        Map<String, File> existingUsers = scanExistingUsers();
-        for (Map.Entry<String, File> existingUser : existingUsers.entrySet()) {
-            File newDirectory = mapper.putIfAbsent(existingUser.getKey(), false);
-            LOGGER.log(Level.INFO, "Migrating user '" + existingUser.getKey() + "' from 'users/" + existingUser.getValue().getName() + "/' to 'users/" + newDirectory.getName() + "/'");
-            Files.move(existingUser.getValue().toPath(), newDirectory.toPath(), StandardCopyOption.REPLACE_EXISTING);
-        }
-        mapper.save();
-        LOGGER.fine("Completed migration of users to userId mapping.");
-    }
-
-}

core/src/main/java/hudson/model/queue/MappingWorksheet.java

@@ -27,6 +27,7 @@ package hudson.model.queue;
 import static java.lang.Math.max;
 
 import com.google.common.collect.Iterables;
+import edu.umd.cs.findbugs.annotations.NonNull;
 import hudson.model.Computer;
 import hudson.model.Executor;
 import hudson.model.Label;
@@ -48,6 +49,7 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.logging.Logger;
+import jenkins.model.Named;
 
 /**
  * Defines a mapping problem for answering "where do we execute this task?"
@@ -114,7 +116,7 @@ public class MappingWorksheet {
         }
     }
 
-    public final class ExecutorChunk extends ReadOnlyList<ExecutorSlot> {
+    public final class ExecutorChunk extends ReadOnlyList<ExecutorSlot> implements Named {
         public final int index;
         public final Computer computer;
         public final Node node;
@@ -150,6 +152,8 @@ public class MappingWorksheet {
         /**
          * Node name.
          */
+        @NonNull
+        @Override
         public String getName() {
             return node.getNodeName();
         }

core/src/main/java/hudson/slaves/NodeProvisioner.java

@@ -251,7 +251,7 @@ public class NodeProvisioner {
                                 LOGGER.log(Level.INFO,
                                         "{0} provisioning successfully completed. "
                                                 + "We have now {1,number,integer} computer(s)",
-                                        new Object[]{f.displayName, jenkins.getComputers().length});
+                                        new Object[]{f.displayName, jenkins.getComputersCollection().size()});
                                 fireOnCommit(f, node);
                             } catch (IOException e) {
                                 LOGGER.log(Level.WARNING,

core/src/main/java/hudson/slaves/SlaveComputer.java

@@ -66,6 +66,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.PrintStream;
+import java.nio.channels.ClosedChannelException;
 import java.nio.charset.Charset;
 import java.security.Security;
 import java.util.ArrayList;
@@ -641,9 +642,11 @@ public class SlaveComputer extends Computer {
                 // Orderly shutdown will have null exception
                 if (cause != null) {
                     offlineCause = new ChannelTermination(cause);
-                    Functions.printStackTrace(cause, taskListener.error("Connection terminated"));
-                } else {
+                }
+                if (cause == null || cause instanceof ClosedChannelException) {
                     taskListener.getLogger().println("Connection terminated");
+                } else {
+                    Functions.printStackTrace(cause, taskListener.error("Connection terminated"));
                 }
                 closeChannel();
                 try {

core/src/main/java/hudson/util/CachingClassLoader.java

@@ -0,0 +1,56 @@
+package hudson.util;
+
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+import org.kohsuke.accmod.Restricted;
+import org.kohsuke.accmod.restrictions.NoExternalUse;
+
+/**
+ *
+ * ClassLoader with internal caching of class loading results.
+ *
+ * <p>
+ * Caches both successful and failed class lookups to avoid redundant delegation
+ * and repeated class resolution attempts. Designed for performance optimization
+ * in systems that repeatedly query class presence (e.g., plugin environments,
+ * reflective loading, optional dependencies).
+ * </p>
+ *
+ * Useful for classloaders that have heavy-weight loadClass() implementations
+ *
+ * @author Dmytro Ukhlov
+ */
+@Restricted(NoExternalUse.class)
+public class CachingClassLoader extends DelegatingClassLoader {
+    private final ConcurrentHashMap<String, Object> cache = new ConcurrentHashMap<>();
+
+    public CachingClassLoader(String name, ClassLoader parent) {
+        super(name, parent);
+    }
+
+    @Override
+    protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
+        Object classOrEmpty = cache.computeIfAbsent(name, key -> {
+            try {
+                return super.loadClass(name, false);
+            } catch (ClassNotFoundException e) {
+                // Not found.
+                return Optional.empty();
+            }
+        });
+
+        if (classOrEmpty == Optional.empty()) {
+            throw new ClassNotFoundException(name);
+        }
+
+        Class<?> clazz = (Class<?>) classOrEmpty;
+        if (resolve) {
+            resolveClass(clazz);
+        }
+        return clazz;
+    }
+
+    public void clearCacheMisses() {
+        cache.values().removeIf(v -> v == Optional.empty());
+    }
+}

core/src/main/java/hudson/util/CopyOnWriteMap.java

@@ -37,7 +37,10 @@ import java.util.Comparator;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.NavigableMap;
+import java.util.NavigableSet;
 import java.util.Set;
+import java.util.SortedMap;
 import java.util.TreeMap;
 
 /**
@@ -64,15 +67,23 @@ public abstract class CopyOnWriteMap<K, V> implements Map<K, V> {
         update(Collections.emptyMap());
     }
 
+    protected Map<K, V> getView() {
+        return view;
+    }
+
+    protected Map<K, V> createView() {
+        return Collections.unmodifiableMap(core);
+    }
+
     protected void update(Map<K, V> m) {
         core = m;
-        view = Collections.unmodifiableMap(core);
+        view = createView();
     }
 
     /**
      * Atomically replaces the entire map by the copy of the specified map.
      */
-    public void replaceBy(Map<? extends K, ? extends V> data) {
+    public synchronized void replaceBy(Map<? extends K, ? extends V> data) {
         Map<K, V> d = copy();
         d.clear();
         d.putAll(data);
@@ -214,7 +225,7 @@ public abstract class CopyOnWriteMap<K, V> implements Map<K, V> {
     /**
      * {@link CopyOnWriteMap} backed by {@link TreeMap}.
      */
-    public static final class Tree<K, V> extends CopyOnWriteMap<K, V> {
+    public static final class Tree<K, V> extends CopyOnWriteMap<K, V> implements NavigableMap<K, V> {
         private final Comparator<K> comparator;
 
         public Tree(Map<K, V> core, Comparator<K> comparator) {
@@ -232,7 +243,7 @@ public abstract class CopyOnWriteMap<K, V> implements Map<K, V> {
         }
 
         @Override
-        protected Map<K, V> copy() {
+        protected TreeMap<K, V> copy() {
             TreeMap<K, V> m = new TreeMap<>(comparator);
             m.putAll(core);
             return m;
@@ -243,6 +254,142 @@ public abstract class CopyOnWriteMap<K, V> implements Map<K, V> {
             update(new TreeMap<>(comparator));
         }
 
+        @Override
+        protected NavigableMap<K, V> createView() {
+            return Collections.unmodifiableNavigableMap((NavigableMap<K, V>) core);
+        }
+
+        @Override
+        protected NavigableMap<K, V> getView() {
+            return (NavigableMap<K, V>) super.getView();
+        }
+
+        @Override
+        public synchronized Entry<K, V> pollFirstEntry() {
+            TreeMap<K, V> d = copy();
+            Entry<K, V> res = d.pollFirstEntry();
+            update(d);
+            return res;
+        }
+
+        @Override
+        public synchronized Entry<K, V> pollLastEntry() {
+            TreeMap<K, V> d = copy();
+            Entry<K, V> res = d.pollLastEntry();
+            update(d);
+            return res;
+        }
+
+        @Override
+        public Entry<K, V> lowerEntry(K key) {
+            return getView().lowerEntry(key);
+        }
+
+        @Override
+        public K lowerKey(K key) {
+            return getView().lowerKey(key);
+        }
+
+        @Override
+        public Entry<K, V> floorEntry(K key) {
+            return getView().floorEntry(key);
+        }
+
+        @Override
+        public K floorKey(K key) {
+            return getView().floorKey(key);
+        }
+
+        @Override
+        public Entry<K, V> ceilingEntry(K key) {
+            return getView().ceilingEntry(key);
+        }
+
+        @Override
+        public K ceilingKey(K key) {
+            return getView().ceilingKey(key);
+        }
+
+        @Override
+        public Entry<K, V> higherEntry(K key) {
+            return getView().higherEntry(key);
+        }
+
+        @Override
+        public K higherKey(K key) {
+            return getView().higherKey(key);
+        }
+
+        @Override
+        public Entry<K, V> firstEntry() {
+            return getView().firstEntry();
+        }
+
+        @Override
+        public Entry<K, V> lastEntry() {
+            return getView().lastEntry();
+        }
+
+        @Override
+        public NavigableMap<K, V> descendingMap() {
+            return getView().descendingMap();
+        }
+
+        @Override
+        public NavigableSet<K> navigableKeySet() {
+            return getView().navigableKeySet();
+        }
+
+        @Override
+        public NavigableSet<K> descendingKeySet() {
+            return getView().descendingKeySet();
+        }
+
+        @Override
+        public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
+            return getView().subMap(fromKey, fromInclusive, toKey, toInclusive);
+        }
+
+        @Override
+        public NavigableMap<K, V> headMap(K toKey, boolean inclusive) {
+            return getView().headMap(toKey, inclusive);
+        }
+
+        @Override
+        public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {
+            return getView().tailMap(fromKey, inclusive);
+        }
+
+        @Override
+        public Comparator<? super K> comparator() {
+            return getView().comparator();
+        }
+
+        @Override
+        public SortedMap<K, V> subMap(K fromKey, K toKey) {
+            return getView().subMap(fromKey, toKey);
+        }
+
+        @Override
+        public SortedMap<K, V> headMap(K toKey) {
+            return getView().headMap(toKey);
+        }
+
+        @Override
+        public SortedMap<K, V> tailMap(K fromKey) {
+            return getView().tailMap(fromKey);
+        }
+
+        @Override
+        public K firstKey() {
+            return getView().firstKey();
+        }
+
+        @Override
+        public K lastKey() {
+            return getView().lastKey();
+        }
+
         public static class ConverterImpl extends TreeMapConverter {
             public ConverterImpl(Mapper mapper) {
                 super(mapper);

core/src/main/java/hudson/util/DelegatingClassLoader.java

@@ -0,0 +1,83 @@
+package hudson.util;
+
+import java.util.Objects;
+import org.kohsuke.accmod.Restricted;
+import org.kohsuke.accmod.restrictions.NoExternalUse;
+
+/**
+ * A {@link ClassLoader} that does not define any classes itself but delegates class loading to
+ * other class loaders to avoid the JDK's per-class-name locking and lock retention.
+ *
+ * <p>This class first attempts to load classes via its {@link ClassLoader#getParent} class loader,
+ * then falls back to {@link ClassLoader#findClass} to allow for custom delegation logic.
+ *
+ * <p>In a parallel-capable {@link ClassLoader}, the JDK maintains a per-name lock object
+ * indefinitely. In Jenkins, many class loading misses across many loaders can accumulate hundreds
+ * of thousands of such locks, retaining significant memory. This loader never defines classes and
+ * bypasses {@link ClassLoader}'s default {@code loadClass} locking; it delegates to the parent
+ * first and then to {@code findClass} for custom delegation.
+ *
+ * <p>The actual defining loader (parent or a delegate) still performs the necessary synchronization
+ * and class definition. A runtime guard ({@link #verify}) throws if this loader ever becomes the
+ * defining loader.
+ *
+ * <p>Subclasses must not call {@code defineClass}; implement delegation in {@code findClass} if
+ * needed and do not mark subclasses as parallel-capable.
+ *
+ * @author Dmytro Ukhlov
+ */
+@Restricted(NoExternalUse.class)
+public abstract class DelegatingClassLoader extends ClassLoader {
+    protected DelegatingClassLoader(String name, ClassLoader parent) {
+        super(name, Objects.requireNonNull(parent));
+    }
+
+    public DelegatingClassLoader(ClassLoader parent) {
+        super(Objects.requireNonNull(parent));
+    }
+
+    /**
+     * Parent-first delegation without synchronizing on {@link #getClassLoadingLock(String)}. This
+     * prevents creation/retention of per-name lock objects in a loader that does not define
+     * classes. The defining loader downstream still serializes class definition as required.
+     *
+     * @param name The binary name of the class
+     * @param resolve If {@code true} then resolve the class
+     * @return The resulting {@link Class} object
+     * @throws ClassNotFoundException If the class could not be found
+     */
+    @Override
+    protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
+        Class<?> c = null;
+        try {
+            c = getParent().loadClass(name);
+        } catch (ClassNotFoundException e) {
+            // ClassNotFoundException thrown if class not found
+            // from the non-null parent class loader
+        }
+
+        if (c == null) {
+            // If still not found, then invoke findClass in order
+            // to find the class.
+            c = findClass(name);
+        }
+
+        verify(c);
+        if (resolve) {
+            resolveClass(c);
+        }
+        return c;
+    }
+
+    /**
+     * Safety check to ensure this delegating loader never becomes the defining loader.
+     *
+     * <p>Fails fast if a subclass erroneously defines a class here, which would violate the
+     * delegation-only contract and could reintroduce locking/retention issues.
+     */
+    private void verify(Class<?> clazz) {
+        if (clazz.getClassLoader() == this) {
+            throw new IllegalStateException("DelegatingClassLoader must not be the defining loader: " + clazz.getName());
+        }
+    }
+}

core/src/main/java/hudson/util/ExistenceCheckingClassLoader.java

@@ -0,0 +1,60 @@
+package hudson.util;
+
+import java.util.Objects;
+import jenkins.util.URLClassLoader2;
+import org.kohsuke.accmod.Restricted;
+import org.kohsuke.accmod.restrictions.NoExternalUse;
+
+/**
+ * A {@link ClassLoader} that verifies the existence of a {@code .class} resource before attempting
+ * to load the class. Intended to sit in front of servlet container loaders we do not control.
+ *
+ * <p>This implementation overrides {@link #loadClass(String, boolean)} and uses {@link
+ * #getResource(String)} to check whether the corresponding <code>.class</code> file is available in
+ * the classpath. If the resource is not found, a {@link ClassNotFoundException} is thrown
+ * immediately.
+ *
+ * <p>Parallel-capable parent loaders retain a per-class-name lock object for every load attempt,
+ * including misses. By checking getResource(name + ".class") first and throwing {@link
+ * ClassNotFoundException} on absence, we avoid calling {@code loadClass} on misses, thus preventing
+ * the parent from populating its lock map for nonexistent classes.
+ *
+ * <p>This class is only needed in {@link hudson.PluginManager.UberClassLoader}. It is unnecessary
+ * for plugin {@link ClassLoader}s (because {@link URLClassLoader2} mitigates lock retention via
+ * {@link ClassLoader#getClassLoadingLock}) and redundant for delegators (because {@link
+ * DelegatingClassLoader} already avoids base locking).
+ *
+ * @author Dmytro Ukhlov
+ * @see ClassLoader
+ * @see #getResource(String)
+ */
+@Restricted(NoExternalUse.class)
+public final class ExistenceCheckingClassLoader extends DelegatingClassLoader {
+
+    public ExistenceCheckingClassLoader(String name, ClassLoader parent) {
+        super(name, Objects.requireNonNull(parent));
+    }
+
+    public ExistenceCheckingClassLoader(ClassLoader parent) {
+        super(Objects.requireNonNull(parent));
+    }
+
+    /**
+     * Short-circuits misses by checking for the {@code .class} resource prior to delegation.
+     * Successful loads behave exactly as the parent would; misses do not touch the parent's
+     * per-name lock map.
+     */
+    @Override
+    protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
+        // Add support for loading of JaCoCo dynamic instrumentation classes
+        if (name.equals("java.lang.$JaCoCo")) {
+            return super.loadClass(name, resolve);
+        }
+
+        if (getResource(name.replace('.', '/') + ".class") == null) {
+            throw new ClassNotFoundException(name);
+        }
+
+        return super.loadClass(name, resolve);
+    }
+}

core/src/main/java/hudson/util/Iterators.java

@@ -35,6 +35,7 @@ import java.util.ListIterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
 import java.util.Set;
+import java.util.function.Function;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
 
@@ -326,6 +327,18 @@ public class Iterators {
         return com.google.common.collect.Iterators.filter(itr, Objects::nonNull);
     }
 
+    /**
+     * Wraps another iterator and map iterable objects.
+     */
+    public static <T, U> Iterator<U> map(final Iterator<T> itr, Function<T, U> mapper) {
+        return new AdaptedIterator<>(itr) {
+            @Override
+            protected U adapt(T item) {
+                return mapper.apply(item);
+            }
+        };
+    }
+
     /**
      * Returns an {@link Iterable} that iterates over all the given {@link Iterable}s.
      *

core/src/main/java/hudson/util/MaskingClassLoader.java

@@ -42,7 +42,7 @@ import java.util.stream.Collectors;
  *
  * @author Kohsuke Kawaguchi
  */
-public class MaskingClassLoader extends ClassLoader {
+public class MaskingClassLoader extends DelegatingClassLoader {
     /**
      * Prefix of the packages that should be hidden.
      */
@@ -50,10 +50,6 @@ public class MaskingClassLoader extends ClassLoader {
 
     private final List<String> masksResources;
 
-    static {
-        registerAsParallelCapable();
-    }
-
     public MaskingClassLoader(ClassLoader parent, String... masks) {
         this(parent, Arrays.asList(masks));
     }

core/src/main/java/hudson/util/jna/RegistryKey.java

@@ -17,6 +17,7 @@ Lesser General Public License for more details.
 package hudson.util.jna;
 
 import com.sun.jna.ptr.IntByReference;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.nio.charset.StandardCharsets;
 import java.util.Collection;
 import java.util.TreeMap;
@@ -89,6 +90,7 @@ public class RegistryKey implements AutoCloseable {
         return convertBufferToInt(getValue(valueName));
     }
 
+    @SuppressFBWarnings(value = "SF_SWITCH_FALLTHROUGH", justification = "TODO needs triage")
     private byte[] getValue(String valueName) {
         IntByReference pType, lpcbData;
         byte[] lpData = new byte[1];
@@ -149,6 +151,7 @@ public class RegistryKey implements AutoCloseable {
     /**
      * Does a specified value exist?
      */
+    @SuppressFBWarnings(value = "SF_SWITCH_FALLTHROUGH", justification = "TODO needs triage")
     public boolean valueExists(String name) {
         IntByReference pType, lpcbData;
         byte[] lpData = new byte[1];
@@ -223,6 +226,7 @@ public class RegistryKey implements AutoCloseable {
      *
      * @return TreeMap with name and value pairs
      */
+    @SuppressFBWarnings(value = "SF_SWITCH_FALLTHROUGH", justification = "TODO needs triage")
     public TreeMap<String, Object> getValues() {
         int dwIndex, result;
         char[] lpValueName;

core/src/main/java/jenkins/agents/CloudSet.java

@@ -141,7 +141,7 @@ public class CloudSet extends AbstractModelObject implements Describable<CloudSe
     @Override
     public ModelObjectWithContextMenu.ContextMenu doChildrenContextMenu(StaplerRequest2 request, StaplerResponse2 response) throws Exception {
         ModelObjectWithContextMenu.ContextMenu m = new ModelObjectWithContextMenu.ContextMenu();
-        Jenkins.get().clouds.stream().forEach(m::add);
+        Jenkins.get().clouds.forEach(m::add);
         return m;
     }
 

core/src/main/java/jenkins/agents/WebSocketAgents.java

@@ -137,10 +137,10 @@ public final class WebSocketAgents extends InvisibleAction implements Unprotecte
         @SuppressFBWarnings(value = "RV_RETURN_VALUE_IGNORED_BAD_PRACTICE", justification = "method signature does not permit plumbing through the return value")
         @Override
         protected void opened() {
+            transport = new Transport();
             Computer.threadPoolForRemoting.submit(() -> {
                 LOGGER.fine(() -> "setting up channel for " + agent);
                 state.fireBeforeChannel(new ChannelBuilder(agent, Computer.threadPoolForRemoting));
-                transport = new Transport();
                 try {
                     state.fireAfterChannel(state.getChannelBuilder().build(transport));
                     LOGGER.fine(() -> "set up channel for " + agent);

core/src/main/java/jenkins/diagnostics/URICheckEncodingMonitor.java

@@ -31,6 +31,11 @@ public class URICheckEncodingMonitor extends AdministrativeMonitor {
         return true;
     }
 
+    @Override
+    public boolean isActivationFake() {
+        return true;
+    }
+
     @Override
     public String getDisplayName() {
         return Messages.URICheckEncodingMonitor_DisplayName();

core/src/main/java/jenkins/management/AdministrativeMonitorsApi.java

@@ -1,50 +0,0 @@
-package jenkins.management;
-
-import hudson.Extension;
-import hudson.model.PageDecorator;
-import hudson.model.RootAction;
-import jakarta.servlet.ServletException;
-import java.io.IOException;
-import jenkins.model.Jenkins;
-import org.kohsuke.accmod.Restricted;
-import org.kohsuke.accmod.restrictions.NoExternalUse;
-import org.kohsuke.stapler.StaplerRequest2;
-import org.kohsuke.stapler.StaplerResponse2;
-import org.kohsuke.stapler.verb.GET;
-
-@Extension
-@Restricted(NoExternalUse.class)
-public class AdministrativeMonitorsApi implements RootAction {
-    @GET
-    public void doNonSecurityPopupContent(StaplerRequest2 req, StaplerResponse2 resp) throws IOException, ServletException {
-        AdministrativeMonitorsApiData viewData = new AdministrativeMonitorsApiData(getDecorator().getNonSecurityAdministrativeMonitors());
-        req.getView(viewData, "monitorsList.jelly").forward(req, resp);
-    }
-
-    @GET
-    public void doSecurityPopupContent(StaplerRequest2 req, StaplerResponse2 resp) throws IOException, ServletException {
-        AdministrativeMonitorsApiData viewData = new AdministrativeMonitorsApiData(getDecorator().getSecurityAdministrativeMonitors());
-        req.getView(viewData, "monitorsList.jelly").forward(req, resp);
-    }
-
-    @Override
-    public String getIconFileName() {
-        return null;
-    }
-
-    @Override
-    public String getDisplayName() {
-        return null;
-    }
-
-    @Override
-    public String getUrlName() {
-        return "administrativeMonitorsApi";
-    }
-
-    private AdministrativeMonitorsDecorator getDecorator() {
-        return Jenkins.get()
-                .getExtensionList(PageDecorator.class)
-                .get(AdministrativeMonitorsDecorator.class);
-    }
-}

core/src/main/java/jenkins/management/AdministrativeMonitorsApiData.java

@@ -1,24 +0,0 @@
-package jenkins.management;
-
-import hudson.model.AdministrativeMonitor;
-import java.util.ArrayList;
-import java.util.List;
-import org.kohsuke.accmod.Restricted;
-import org.kohsuke.accmod.restrictions.NoExternalUse;
-
-@Restricted(NoExternalUse.class)
-public class AdministrativeMonitorsApiData {
-    private final List<AdministrativeMonitor> monitorsList = new ArrayList<>();
-
-    AdministrativeMonitorsApiData(List<AdministrativeMonitor> monitors) {
-        monitorsList.addAll(monitors);
-    }
-
-    public List<AdministrativeMonitor> getMonitorsList() {
-        return this.monitorsList;
-    }
-
-    public boolean hasActiveMonitors() {
-        return !this.monitorsList.isEmpty();
-    }
-}

core/src/main/java/jenkins/management/AdministrativeMonitorsDecorator.java

@@ -1,173 +0,0 @@
-/*
- * The MIT License
- *
- * Copyright (c) 2016, Daniel Beck, CloudBees, Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-package jenkins.management;
-
-import edu.umd.cs.findbugs.annotations.NonNull;
-import hudson.Extension;
-import hudson.diagnosis.ReverseProxySetupMonitor;
-import hudson.model.AdministrativeMonitor;
-import hudson.model.PageDecorator;
-import hudson.util.HudsonIsLoading;
-import hudson.util.HudsonIsRestarting;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-import java.util.stream.Collectors;
-import jenkins.diagnostics.URICheckEncodingMonitor;
-import jenkins.model.Jenkins;
-import org.kohsuke.accmod.Restricted;
-import org.kohsuke.accmod.restrictions.NoExternalUse;
-import org.kohsuke.stapler.Ancestor;
-import org.kohsuke.stapler.Stapler;
-import org.kohsuke.stapler.StaplerRequest2;
-
-/**
- * Show notifications and popups for active administrative monitors on all pages.
- */
-@Extension
-@Restricted(NoExternalUse.class)
-public class AdministrativeMonitorsDecorator extends PageDecorator {
-    private final Collection<String> ignoredJenkinsRestOfUrls = new ArrayList<>();
-
-    public AdministrativeMonitorsDecorator() {
-        // otherwise this would be added to every internal context menu building request
-        ignoredJenkinsRestOfUrls.add("contextMenu");
-    }
-
-    @NonNull
-    @Override
-    public String getDisplayName() {
-        return Messages.AdministrativeMonitorsDecorator_DisplayName();
-    }
-
-    // Used by Jelly
-    public Collection<AdministrativeMonitor> filterNonSecurityAdministrativeMonitors(Collection<AdministrativeMonitor> activeMonitors) {
-        return this.filterActiveAdministrativeMonitors(activeMonitors, false);
-    }
-
-    // Used by Jelly
-    public Collection<AdministrativeMonitor> filterSecurityAdministrativeMonitors(Collection<AdministrativeMonitor> activeMonitors) {
-        return this.filterActiveAdministrativeMonitors(activeMonitors, true);
-    }
-
-    /**
-     * Prevent us to compute multiple times the {@link AdministrativeMonitor#isActivated()} by re-using the same list
-     */
-    private Collection<AdministrativeMonitor> filterActiveAdministrativeMonitors(Collection<AdministrativeMonitor> activeMonitors, boolean isSecurity) {
-        Collection<AdministrativeMonitor> active = new ArrayList<>();
-        for (AdministrativeMonitor am : activeMonitors) {
-            if (am.isSecurity() == isSecurity) {
-                active.add(am);
-            }
-        }
-        return active;
-    }
-
-    // Used by API
-    public List<AdministrativeMonitor> getNonSecurityAdministrativeMonitors() {
-        Collection<AdministrativeMonitor> allowedMonitors = getMonitorsToDisplay();
-
-        if (allowedMonitors == null) {
-            return Collections.emptyList();
-        }
-
-        return allowedMonitors.stream()
-                .filter(administrativeMonitor -> !administrativeMonitor.isSecurity())
-                .collect(Collectors.toList());
-    }
-
-    // Used by API
-    public List<AdministrativeMonitor> getSecurityAdministrativeMonitors() {
-        Collection<AdministrativeMonitor> allowedMonitors = getMonitorsToDisplay();
-
-        if (allowedMonitors == null) {
-            return Collections.emptyList();
-        }
-
-        return allowedMonitors.stream()
-                .filter(AdministrativeMonitor::isSecurity)
-                .collect(Collectors.toList());
-    }
-
-    private Collection<AdministrativeMonitor> getAllActiveAdministrativeMonitors() {
-        Collection<AdministrativeMonitor> active = new ArrayList<>();
-        for (AdministrativeMonitor am : Jenkins.get().getActiveAdministrativeMonitors()) {
-            if (am instanceof ReverseProxySetupMonitor) {
-                // TODO make reverse proxy monitor work when shown on any URL
-                continue;
-            }
-            if (am instanceof URICheckEncodingMonitor) {
-                // TODO make URI encoding monitor work when shown on any URL
-                continue;
-            }
-            active.add(am);
-        }
-        return active;
-    }
-
-    /**
-     * Compute the administrative monitors that are active and should be shown.
-     * This is done only when the instance is currently running and the user has the permission to read them.
-     *
-     * @return the list of active monitors if we should display them, otherwise null.
-     */
-    public Collection<AdministrativeMonitor> getMonitorsToDisplay() {
-        if (!(AdministrativeMonitor.hasPermissionToDisplay())) {
-            return null;
-        }
-
-        StaplerRequest2 req = Stapler.getCurrentRequest2();
-
-        if (req == null) {
-            return null;
-        }
-        List<Ancestor> ancestors = req.getAncestors();
-
-        if (ancestors == null || ancestors.isEmpty()) {
-            // ???
-            return null;
-        }
-
-        Ancestor a = ancestors.get(ancestors.size() - 1);
-        Object o = a.getObject();
-
-        // don't show while Jenkins is loading
-        if (o instanceof HudsonIsLoading || o instanceof HudsonIsRestarting) {
-            return null;
-        }
-
-        // don't show for some URLs served directly by Jenkins
-        if (o instanceof Jenkins) {
-            String url = a.getRestOfUrl();
-
-            if (ignoredJenkinsRestOfUrls.contains(url)) {
-                return null;
-            }
-        }
-
-        return getAllActiveAdministrativeMonitors();
-    }
-}

core/src/main/java/jenkins/management/Badge.java

@@ -66,7 +66,6 @@ public class Badge {
      *
      * @param text  The text to be shown in the badge.
      *      Keep it short, ideally just a number. More than 6 or 7 characters do not look good. Avoid spaces as they will lead to line breaks.
-     *      as this might lead to line breaks.
      * @param tooltip  The tooltip to show for the badge.
      *      Do not include html tags.
      * @param severity  The severity of the badge (danger, warning, info)

core/src/main/java/jenkins/model/FullyNamed.java

@@ -0,0 +1,17 @@
+package jenkins.model;
+
+import edu.umd.cs.findbugs.annotations.NonNull;
+
+/**
+ * An interface for objects that have a name and a parent, so exposing a full name.
+ */
+public interface FullyNamed {
+    /**
+     * Returns the full name of this object, which is a qualified name
+     * that includes the names of all its ancestors, separated by '/'.
+     *
+     * @return the full name of this object.
+     */
+    @NonNull
+    String getFullName();
+}

core/src/main/java/jenkins/model/FullyNamedModelObject.java

@@ -0,0 +1,23 @@
+package jenkins.model;
+
+import hudson.model.ModelObject;
+import jenkins.security.stapler.StaplerAccessibleType;
+
+/**
+ * A model object that has a human-readable full name. This is usually valid when nested as part of an object hierarchy.
+ *
+ * <p>
+ * This interface is used to mark objects that can be qualified in the context of a Jenkins instance.
+ * It is typically used for objects that are part of the Jenkins model and can be referenced by their names.
+ *
+ * @see ModelObject
+ */
+@StaplerAccessibleType
+public interface FullyNamedModelObject extends ModelObject {
+    /**
+     * Works like {@link #getDisplayName()} but return
+     * the full path that includes all the display names
+     * of the ancestors in an unspecified format.
+     */
+    String getFullDisplayName();
+}

core/src/main/java/jenkins/model/HistoricalBuild.java

@@ -29,7 +29,6 @@ import edu.umd.cs.findbugs.annotations.NonNull;
 import hudson.markup.MarkupFormatter;
 import hudson.model.BallColor;
 import hudson.model.BuildBadgeAction;
-import hudson.model.ModelObject;
 import hudson.model.ParameterValue;
 import hudson.model.ParametersAction;
 import hudson.model.Queue;
@@ -48,7 +47,7 @@ import org.kohsuke.accmod.restrictions.Beta;
  * @since 2.477
  */
 @Restricted(Beta.class)
-public interface HistoricalBuild extends ModelObject {
+public interface HistoricalBuild extends FullyNamedModelObject {
 
     /**
      * @return A build number
@@ -74,12 +73,6 @@ public interface HistoricalBuild extends ModelObject {
     @CheckForNull
     String getDescription();
 
-    /**
-     * @return a human-readable full display name of this build.
-     */
-    @NonNull
-    String getFullDisplayName();
-
     /**
      * Get the {@link Queue.Item#getId()} of the original queue item from where this {@link HistoricalBuild} instance
      * originated.

core/src/main/java/jenkins/model/IComputer.java

@@ -27,7 +27,7 @@ package jenkins.model;
 import edu.umd.cs.findbugs.annotations.NonNull;
 import hudson.Util;
 import hudson.model.Computer;
-import hudson.model.Node;
+import hudson.model.ModelObject;
 import hudson.security.ACL;
 import hudson.security.AccessControlled;
 import java.util.List;
@@ -45,13 +45,7 @@ import org.kohsuke.accmod.restrictions.Beta;
  * @since 2.480
  */
 @Restricted(Beta.class)
-public interface IComputer extends AccessControlled, IconSpec {
-    /**
-     * Returns {@link Node#getNodeName() the name of the node}.
-     */
-    @NonNull
-    String getName();
-
+public interface IComputer extends AccessControlled, IconSpec, ModelObject, Named {
     /**
      * Used to render the list of executors.
      * @return a snapshot of the executor display information
@@ -60,16 +54,14 @@ public interface IComputer extends AccessControlled, IconSpec {
     List<? extends IDisplayExecutor> getDisplayExecutors();
 
     /**
-     * @return {@code true} if the node is offline. {@code false} if it is online.
+     * Returns whether the agent is offline for scheduling new tasks.
+     * Even if {@code true}, the agent may still be connected to the controller and executing a task,
+     * but is considered offline for scheduling.
+     * @return {@code true} if the agent is offline; {@code false} if online.
+     * @see #isConnected()
      */
     boolean isOffline();
 
-    /**
-     * @return the node name for UI purposes.
-     */
-    @NonNull
-    String getDisplayName();
-
     /**
      * Returns {@code true} if the computer is accepting tasks. Needed to allow agents programmatic suspension of task
      * scheduling that does not overlap with being offline.
@@ -192,10 +184,21 @@ public interface IComputer extends AccessControlled, IconSpec {
     int countExecutors();
 
     /**
-     * @return true if the computer is online.
+     * Indicates whether the agent can accept a new task when it becomes idle.
+     * {@code false} does not necessarily mean the agent is disconnected.
+     * @return {@code true} if the agent is online.
+     * @see #isConnected()
      */
     boolean isOnline();
 
+    /**
+     * Indicates whether the agent is actually connected to the controller.
+     * @return {@code true} if the agent is connected to the controller.
+     */
+    default boolean isConnected() {
+        return isOnline();
+    }
+
     /**
      * @return the number of {@link IExecutor}s that are idle right now.
      */

core/src/main/java/jenkins/model/IDisplayExecutor.java

@@ -25,6 +25,7 @@
 package jenkins.model;
 
 import edu.umd.cs.findbugs.annotations.NonNull;
+import hudson.model.ModelObject;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.Beta;
 
@@ -34,13 +35,7 @@ import org.kohsuke.accmod.restrictions.Beta;
  * @since 2.480
  */
 @Restricted(Beta.class)
-public interface IDisplayExecutor {
-    /**
-     * @return The UI label for this executor.
-     */
-    @NonNull
-    String getDisplayName();
-
+public interface IDisplayExecutor extends ModelObject {
     /**
      * @return the URL where to reach specifically this executor, relative to Jenkins URL.
      */

core/src/main/java/jenkins/model/Jenkins.java

@@ -1731,6 +1731,7 @@ public class Jenkins extends AbstractCIBase implements DirectlyModifiableTopLeve
     }
 
 
+    @NonNull
     @Override
     public String getFullName() {
         return "";

core/src/main/java/jenkins/model/Named.java

@@ -0,0 +1,19 @@
+package jenkins.model;
+
+import edu.umd.cs.findbugs.annotations.NonNull;
+
+/**
+ * An object that has a name.
+ * <p>
+ * This interface is used to provide a consistent way to retrieve the name of an object in Jenkins.
+ * It is typically implemented by objects that need to be identified by a name, such as tasks, nodes, or other model objects.
+ */
+public interface Named {
+    /**
+     * Returns the name of this object.
+     *
+     * @return the name of this object, never null.
+     */
+    @NonNull
+    String getName();
+}

core/src/main/java/jenkins/model/ParameterizedJobMixIn.java

@@ -24,6 +24,7 @@
 
 package jenkins.model;
 
+import static jakarta.servlet.http.HttpServletResponse.SC_BAD_REQUEST;
 import static jakarta.servlet.http.HttpServletResponse.SC_CONFLICT;
 import static jakarta.servlet.http.HttpServletResponse.SC_CREATED;
 
@@ -201,7 +202,7 @@ public abstract class ParameterizedJobMixIn<JobT extends Job<JobT, RunT> & Param
         }
 
         if (!asJob().isBuildable()) {
-            throw HttpResponses.error(SC_CONFLICT, new IOException(asJob().getFullName() + " is not buildable"));
+            throw HttpResponses.errorWithoutStack(SC_CONFLICT, asJob().getFullName() + " is not buildable");
         }
 
         // if a build is parameterized, let that take over
@@ -238,12 +239,12 @@ public abstract class ParameterizedJobMixIn<JobT extends Job<JobT, RunT> & Param
 
         ParametersDefinitionProperty pp = asJob().getProperty(ParametersDefinitionProperty.class);
         if (!asJob().isBuildable()) {
-            throw HttpResponses.error(SC_CONFLICT, new IOException(asJob().getFullName() + " is not buildable!"));
+            throw HttpResponses.errorWithoutStack(SC_CONFLICT, asJob().getFullName() + " is not buildable");
         }
         if (pp != null) {
             pp.buildWithParameters(req, rsp, delay);
         } else {
-            throw new IllegalStateException("This build is not parameterized!");
+            throw HttpResponses.errorWithoutStack(SC_BAD_REQUEST, asJob().getFullName() + " is not parameterized");
         }
     }
 

core/src/main/java/jenkins/model/lazy/AbstractLazyLoadRunMap.java

@@ -26,30 +26,26 @@ package jenkins.model.lazy;
 
 import static jenkins.model.lazy.AbstractLazyLoadRunMap.Direction.ASC;
 import static jenkins.model.lazy.AbstractLazyLoadRunMap.Direction.DESC;
+import static jenkins.model.lazy.AbstractLazyLoadRunMap.Direction.EXACT;
 
 import edu.umd.cs.findbugs.annotations.CheckForNull;
 import hudson.model.Job;
 import hudson.model.Run;
 import hudson.model.RunMap;
 import hudson.model.listeners.RunListener;
+import hudson.util.CopyOnWriteMap;
 import java.io.File;
 import java.io.IOException;
-import java.util.AbstractCollection;
 import java.util.AbstractMap;
-import java.util.AbstractSet;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
-import java.util.Iterator;
-import java.util.ListIterator;
 import java.util.Map;
+import java.util.NavigableMap;
 import java.util.NoSuchElementException;
 import java.util.Set;
 import java.util.SortedMap;
-import java.util.Spliterator;
-import java.util.Spliterators;
 import java.util.TreeMap;
-import java.util.function.IntConsumer;
 import java.util.function.IntPredicate;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -87,203 +83,44 @@ import org.kohsuke.accmod.restrictions.NoExternalUse;
  *
  * <p>
  * Some of the {@link SortedMap} operations are inefficiently implemented, by
- * {@linkplain #all() loading all the build records eagerly}. We hope to replace
+ * loading all the build records eagerly. We hope to replace
  * these implementations by more efficient lazy-loading ones as we go.
  *
  * <p>
  * Object lock of {@code this} is used to make sure mutation occurs sequentially.
  * That is, ensure that only one thread is actually calling {@link #retrieve(File)} and
- * updating {@link jenkins.model.lazy.AbstractLazyLoadRunMap.Index#byNumber}.
+ * updating {@link jenkins.model.lazy.AbstractLazyLoadRunMap#core}.
  *
  * @author Kohsuke Kawaguchi
  * @since 1.485
  */
 public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R> implements SortedMap<Integer, R> {
-    /**
-     * Used in {@link #all()} to quickly determine if we've already loaded everything.
-     */
-    private volatile boolean fullyLoaded;
-
-    /**
-     * Currently visible index.
-     * Updated atomically. Once set to this field, the index object may not be modified.
-     */
-    private volatile Index index = new Index();
-    private LazyLoadRunMapEntrySet<R> entrySet = new LazyLoadRunMapEntrySet<>(this);
-
-    private transient volatile Set<Integer> keySet;
-    private transient volatile Collection<R> values;
+    private final CopyOnWriteMap.Tree<Integer, BuildReference<R>> core = new CopyOnWriteMap.Tree<>(
+            Collections.reverseOrder());
+    private final BuildReferenceMapAdapter.Resolver<R> buildResolver = new BuildReferenceMapAdapterResolver();
+    private final BuildReferenceMapAdapter<R> adapter = new BuildReferenceMapAdapter<>(core, buildResolver) {
+        @Override
+        protected boolean removeValue(R value) {
+            return AbstractLazyLoadRunMap.this.removeValue(value);
+        }
+    };
 
     @Override
     public Set<Integer> keySet() {
-        Set<Integer> ks = keySet;
-        if (ks == null) {
-            ks = new AbstractSet<>() {
-                @Override
-                public Iterator<Integer> iterator() {
-                    return new Iterator() {
-                        private final Iterator<Entry<Integer, R>> it = entrySet().iterator();
-
-                        @Override
-                        public boolean hasNext() {
-                            return it.hasNext();
-                        }
-
-                        @Override
-                        public Integer next() {
-                            return it.next().getKey();
-                        }
-
-                        @Override
-                        public void remove() {
-                            it.remove();
-                        }
-                    };
-                }
-
-                @Override
-                public Spliterator<Integer> spliterator() {
-                    return new Spliterators.AbstractIntSpliterator(
-                            Long.MAX_VALUE,
-                            Spliterator.DISTINCT | Spliterator.ORDERED | Spliterator.SORTED) {
-                        private final Iterator<Integer> it = iterator();
-
-                        @Override
-                        public boolean tryAdvance(IntConsumer action) {
-                            if (action == null) {
-                                throw new NullPointerException();
-                            }
-                            if (it.hasNext()) {
-                                action.accept(it.next());
-                                return true;
-                            }
-                            return false;
-                        }
-
-                        @Override
-                        public Comparator<Integer> getComparator() {
-                            return Collections.reverseOrder();
-                        }
-                    };
-                }
-
-                @Override
-                public int size() {
-                    return AbstractLazyLoadRunMap.this.size();
-                }
-
-                @Override
-                public boolean isEmpty() {
-                    return AbstractLazyLoadRunMap.this.isEmpty();
-                }
-
-                @Override
-                public void clear() {
-                    AbstractLazyLoadRunMap.this.clear();
-                }
-
-                @Override
-                public boolean contains(Object k) {
-                    return AbstractLazyLoadRunMap.this.containsKey(k);
-                }
-            };
-            keySet = ks;
-        }
-        return ks;
+        return adapter.keySet();
     }
 
     @Override
     public Collection<R> values() {
-        Collection<R> vals = values;
-        if (vals == null) {
-            vals = new AbstractCollection<>() {
-                @Override
-                public Iterator<R> iterator() {
-                    return new Iterator<>() {
-                        private final Iterator<Entry<Integer, R>> it = entrySet().iterator();
-
-                        @Override
-                        public boolean hasNext() {
-                            return it.hasNext();
-                        }
-
-                        @Override
-                        public R next() {
-                            return it.next().getValue();
-                        }
-
-                        @Override
-                        public void remove() {
-                            it.remove();
-                        }
-                    };
-                }
-
-                @Override
-                public Spliterator<R> spliterator() {
-                    return Spliterators.spliteratorUnknownSize(
-                            iterator(), Spliterator.DISTINCT | Spliterator.ORDERED);
-                }
-
-                @Override
-                public int size() {
-                    return AbstractLazyLoadRunMap.this.size();
-                }
-
-                @Override
-                public boolean isEmpty() {
-                    return AbstractLazyLoadRunMap.this.isEmpty();
-                }
-
-                @Override
-                public void clear() {
-                    AbstractLazyLoadRunMap.this.clear();
-                }
-
-                @Override
-                public boolean contains(Object v) {
-                    return AbstractLazyLoadRunMap.this.containsValue(v);
-                }
-            };
-            values = vals;
-        }
-        return vals;
+        return adapter.values();
     }
 
-    /**
-     * Historical holder for map.
-     *
-     * TODO all this mess including {@link #numberOnDisk} could probably be simplified to a single {@code TreeMap<Integer,BuildReference<R>>}
-     * where a null value means not yet loaded and a broken entry just uses {@code NoHolder}.
-     *
-     * The idiom is that you put yourself in a synchronized block, {@linkplain #copy() make a copy of this},
-     * update the copy, then set it to {@link #index}.
-     */
-    private class Index {
-        /**
-         * Stores the mapping from build number to build, for builds that are already loaded.
-         *
-         * If we have known load failure of the given ID, we record that in the map
-         * by using the null value (not to be confused with a non-null {@link BuildReference}
-         * with null referent, which just means the record was GCed.)
-         */
-        private final TreeMap<Integer, BuildReference<R>> byNumber;
-
-        private Index() {
-            byNumber = new TreeMap<>(Collections.reverseOrder());
-        }
-
-        private Index(Index rhs) {
-            byNumber = new TreeMap<>(rhs.byNumber);
-        }
+    @Override
+    public Set<Entry<Integer, R>> entrySet() {
+        assert baseDirInitialized();
+        return adapter.entrySet();
     }
 
-    /**
-     * Build numbers found on disk, in the ascending order.
-     */
-    // copy on write
-    private volatile SortedIntList numberOnDisk = new SortedIntList(0);
-
     /**
      * Base directory for data.
      * In effect this is treated as a final field, but can't mark it final
@@ -330,8 +167,6 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
      * @since 1.507
      */
     public synchronized void purgeCache() {
-        index = new Index();
-        fullyLoaded = false;
         loadNumberOnDisk();
     }
 
@@ -343,7 +178,7 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
             // the job may have just been created
             kids = MemoryReductionUtil.EMPTY_STRING_ARRAY;
         }
-        SortedIntList list = new SortedIntList(kids.length / 2);
+        TreeMap<Integer, BuildReference<R>> newBuildRefsMap = new TreeMap<>();
         var allower = createLoadAllower();
         for (String s : kids) {
             if (!BUILD_NUMBER.matcher(s).matches()) {
@@ -353,7 +188,7 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
             try {
                 int buildNumber = Integer.parseInt(s);
                 if (allower.test(buildNumber)) {
-                    list.add(buildNumber);
+                    newBuildRefsMap.put(buildNumber, new BuildReference<>(s));
                 } else {
                     LOGGER.fine(() -> "declining to consider " + buildNumber + " in " + dir);
                 }
@@ -361,8 +196,7 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
                 // matched BUILD_NUMBER but not an int?
             }
         }
-        list.sort();
-        numberOnDisk = list;
+        core.replaceBy(newBuildRefsMap);
     }
 
     @Restricted(NoExternalUse.class)
@@ -384,13 +218,10 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
     public final void recognizeNumber(int buildNumber) {
         if (new File(dir, Integer.toString(buildNumber)).isDirectory()) {
             synchronized (this) {
-                SortedIntList list = new SortedIntList(numberOnDisk);
-                if (list.contains(buildNumber)) {
+                if (this.core.containsKey(buildNumber)) {
                     LOGGER.fine(() -> "already knew about " + buildNumber + " in " + dir);
                 } else {
-                    list.add(buildNumber);
-                    list.sort();
-                    numberOnDisk = list;
+                    core.put(buildNumber, new BuildReference<>(String.valueOf(buildNumber)));
                     LOGGER.fine(() -> "recognizing " + buildNumber + " in " + dir);
                 }
             }
@@ -401,25 +232,36 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
 
     @Override
     public Comparator<? super Integer> comparator() {
-        return Collections.reverseOrder();
+        return core.comparator();
     }
 
     @Override
     public boolean isEmpty() {
-        return search(Integer.MAX_VALUE, DESC) == null;
+        return adapter.isEmpty();
     }
 
     @Override
-    public Set<Entry<Integer, R>> entrySet() {
-        assert baseDirInitialized();
-        return entrySet;
+    public boolean containsKey(Object value) {
+        return adapter.containsKey(value);
+    }
+
+    @Override
+    public boolean containsValue(Object value) {
+        return adapter.containsValue(value);
     }
 
     /**
      * Returns a read-only view of records that has already been loaded.
      */
     public SortedMap<Integer, R> getLoadedBuilds() {
-        return Collections.unmodifiableSortedMap(new BuildReferenceMapAdapter<>(this, index.byNumber));
+        TreeMap<Integer, BuildReference<R>> res = new TreeMap<>(Comparator.reverseOrder());
+        for (var entry : this.core.entrySet()) {
+            BuildReference<R> buildRef = entry.getValue();
+            if (buildRef.isSet() && !buildRef.isUnloadable()) {
+                res.put(entry.getKey(), buildRef);
+            }
+        }
+        return new BuildReferenceMapAdapter<>(res, buildResolver);
     }
 
     /**
@@ -430,47 +272,27 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
      */
     @Override
     public SortedMap<Integer, R> subMap(Integer fromKey, Integer toKey) {
-        // TODO: if this method can produce a lazy map, that'd be wonderful
-        // because due to the lack of floor/ceil/higher/lower kind of methods
-        // to look up keys in SortedMap, various places of Jenkins rely on
-        // subMap+firstKey/lastKey combo.
-
-        R start = search(fromKey, DESC);
-        if (start == null)    return EMPTY_SORTED_MAP;
-
-        R end = search(toKey, ASC);
-        if (end == null)      return EMPTY_SORTED_MAP;
-
-        for (R i = start; i != end; ) {
-            i = search(getNumberOf(i) - 1, DESC);
-            assert i != null;
-        }
-
-        return Collections.unmodifiableSortedMap(new BuildReferenceMapAdapter<>(this, index.byNumber.subMap(fromKey, toKey)));
+        return adapter.subMap(fromKey, toKey);
     }
 
     @Override
     public SortedMap<Integer, R> headMap(Integer toKey) {
-        return subMap(Integer.MAX_VALUE, toKey);
+        return adapter.headMap(toKey);
     }
 
     @Override
     public SortedMap<Integer, R> tailMap(Integer fromKey) {
-        return subMap(fromKey, Integer.MIN_VALUE);
+        return adapter.tailMap(fromKey);
     }
 
     @Override
     public Integer firstKey() {
-        R r = newestBuild();
-        if (r == null)    throw new NoSuchElementException();
-        return getNumberOf(r);
+        return adapter.firstKey();
     }
 
     @Override
     public Integer lastKey() {
-        R r = oldestBuild();
-        if (r == null)    throw new NoSuchElementException();
-        return getNumberOf(r);
+        return adapter.lastKey();
     }
 
     public R newestBuild() {
@@ -483,11 +305,7 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
 
     @Override
     public R get(Object key) {
-        if (key instanceof Integer) {
-            int n = (Integer) key;
-            return get(n);
-        }
-        return super.get(key);
+        return adapter.get(key);
     }
 
     public R get(int n) {
@@ -503,7 +321,7 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
      * @since 2.14
      */
     public boolean runExists(int number) {
-        return numberOnDisk.contains(number);
+        return this.core.containsKey(number);
     }
 
     /**
@@ -518,72 +336,51 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
      *      If DESC, finds the closest #M that satisfies M ≤ N.
      */
     public @CheckForNull R search(final int n, final Direction d) {
-        switch (d) {
-        case EXACT:
-            return getByNumber(n);
-        case ASC:
-            for (int m : numberOnDisk) {
-                if (m < n) {
-                    // TODO could be made more efficient with numberOnDisk.find
-                    continue;
-                }
-                R r = getByNumber(m);
-                if (r != null) {
-                    return r;
-                }
-            }
-            return null;
-        case DESC:
-            // TODO again could be made more efficient
-            ListIterator<Integer> iterator = numberOnDisk.listIterator(numberOnDisk.size());
-            while (iterator.hasPrevious()) {
-                int m = iterator.previous();
-                if (m > n) {
-                    continue;
-                }
-                R r = getByNumber(m);
-                if (r != null) {
-                    return r;
-                }
-            }
-            return null;
-        default:
-            throw new AssertionError();
+        if (d == EXACT) {
+            return this.adapter.get(n);
         }
+        // prepare sub map, where we need to find first resolvable entry
+        NavigableMap<Integer, BuildReference<R>> subCore = (d == ASC)
+                ? core.headMap(n, true).descendingMap()
+                : core.tailMap(n, true);
+        // wrap with BuildReferenceMapAdapter to skip unresolvable entries
+        return new BuildReferenceMapAdapter<>(subCore, buildResolver).values().stream().findFirst().orElse(null);
     }
 
     public R getById(String id) {
         return getByNumber(Integer.parseInt(id));
     }
 
-    public R getByNumber(int n) {
-        Index snapshot = index;
-        if (snapshot.byNumber.containsKey(n)) {
-            BuildReference<R> ref = snapshot.byNumber.get(n);
-            if (ref == null) {
-                LOGGER.fine(() -> "known failure of #" + n + " in " + dir);
-                return null;
-            }
-            R v = unwrap(ref);
-            if (v != null) {
+    /**
+     * Ensure loading referent object if needed, cache it and return
+     * Save that object as 'unloadable' in case of failure to avoid next load attempts
+     *
+     * @param ref reference object to be resolved
+     * @return R referent build object, or null if it can't be resolved
+     */
+    private R resolveBuildRef(BuildReference<R> ref) {
+        if (ref == null || ref.isUnloadable()) {
+            return null;
+        }
+        R v;
+        if ((v = ref.get()) != null) {
+            return v; // already in memory
+        }
+        // otherwise fall through to load
+        synchronized (this) {
+            if ((v = ref.get()) != null) {
                 return v; // already in memory
             }
-            // otherwise fall through to load
-        }
-        synchronized (this) {
-            if (index.byNumber.containsKey(n)) { // JENKINS-22767: recheck inside lock
-                BuildReference<R> ref = index.byNumber.get(n);
-                if (ref == null) {
-                    LOGGER.fine(() -> "known failure of #" + n + " in " + dir);
+            int n = ref.number;
+            if (allowLoad(n)) {
+                v = load(n);
+                // save if build unloadable
+                if (v == null) {
+                    ref.setUnloadable();
                     return null;
                 }
-                R v = unwrap(ref);
-                if (v != null) {
-                    return v;
-                }
-            }
-            if (allowLoad(n)) {
-                return load(n, null);
+                ref.set(v);
+                return v;
             } else {
                 LOGGER.fine(() -> "declining to load " + n + " in " + dir);
                 return null;
@@ -591,17 +388,25 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
         }
     }
 
+    public R getByNumber(int n) {
+        return adapter.get(n);
+    }
+
     /**
      * @return the highest recorded build number, or 0 if there are none
      */
     @Restricted(NoExternalUse.class)
     public synchronized int maxNumberOnDisk() {
-        return numberOnDisk.max();
+        try {
+            return this.core.firstKey();
+        } catch (NoSuchElementException ignored) {
+            return 0;
+        }
     }
 
     protected final synchronized void proposeNewNumber(int number) throws IllegalStateException {
         if (number <= maxNumberOnDisk()) {
-            throw new IllegalStateException("JENKINS-27530: cannot create a build with number " + number + " since that (or higher) is already in use among " + numberOnDisk);
+            throw new IllegalStateException("JENKINS-27530: cannot create a build with number " + number + " since that (or higher) is already in use among " + keySet());
         }
     }
 
@@ -616,95 +421,36 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
     @Override
     public synchronized R put(Integer key, R r) {
         int n = getNumberOf(r);
-
-        Index copy = copy();
-        BuildReference<R> ref = createReference(r);
-        BuildReference<R> old = copy.byNumber.put(n, ref);
-        index = copy;
-
-        if (!numberOnDisk.contains(n)) {
-            SortedIntList a = new SortedIntList(numberOnDisk);
-            a.add(n);
-            a.sort();
-            numberOnDisk = a;
-        }
-
-        entrySet.clearCache();
-
-        return unwrap(old);
-    }
-
-    private R unwrap(BuildReference<R> ref) {
-        return ref != null ? ref.get() : null;
+        BuildReference<R> old = core.put(n, createReference(r));
+        return resolveBuildRef(old);
     }
 
     @Override
-    public synchronized void putAll(Map<? extends Integer, ? extends R> rhs) {
-        Index copy = copy();
-        for (R r : rhs.values()) {
-            BuildReference<R> ref = createReference(r);
-            copy.byNumber.put(getNumberOf(r), ref);
+    public synchronized void putAll(Map<? extends Integer, ? extends R> newData) {
+        TreeMap<Integer, BuildReference<R>> newWrapperData = new TreeMap<>();
+        for (Map.Entry<? extends Integer, ? extends R> entry : newData.entrySet()) {
+            newWrapperData.put(entry.getKey(), createReference(entry.getValue()));
         }
-        index = copy;
+        core.putAll(newWrapperData);
     }
 
-    /**
-     * Loads all the build records to fully populate the map.
-     * Calling this method results in eager loading everything,
-     * so the whole point of this class is to avoid this call as much as possible
-     * for typical code path.
-     *
-     * @return
-     *      fully populated map.
-     */
-    /*package*/ TreeMap<Integer, BuildReference<R>> all() {
-        if (!fullyLoaded) {
-            synchronized (this) {
-                if (!fullyLoaded) {
-                    Index copy = copy();
-                    for (Integer number : numberOnDisk) {
-                        if (!copy.byNumber.containsKey(number))
-                            load(number, copy);
-                    }
-                    index = copy;
-                    fullyLoaded = true;
-                }
-            }
-        }
-        return index.byNumber;
+    @Override
+    public R remove(Object key) {
+        return adapter.remove(key);
     }
 
-    /**
-     * Creates a duplicate for the COW data structure in preparation for mutation.
-     */
-    private Index copy() {
-        return new Index(index);
-   }
-
     /**
      * Tries to load the record #N.
      *
      * @return null if the data failed to load.
      */
-    private R load(int n, Index editInPlace) {
+    private R load(int n) {
         assert Thread.holdsLock(this);
         assert dir != null;
-        R v = load(new File(dir, String.valueOf(n)), editInPlace);
-        if (v == null && editInPlace != null) {
-            // remember the failure.
-            // if editInPlace==null, we can create a new copy for this, but not sure if it's worth doing,
-            // TODO should we also update numberOnDisk?
-            editInPlace.byNumber.put(n, null);
-        }
-        return v;
+        return load(new File(dir, String.valueOf(n)));
     }
 
-    /**
-     * @param editInPlace
-     *      If non-null, update this data structure.
-     *      Otherwise do a copy-on-write of {@link #index}
-     */
-    private R load(File dataDir, Index editInPlace) {
+    private R load(File dataDir) {
         assert Thread.holdsLock(this);
         try {
             R r = retrieve(dataDir);
@@ -712,15 +458,6 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
                 LOGGER.fine(() -> "nothing in " + dataDir);
                 return null;
             }
-
-            Index copy = editInPlace != null ? editInPlace : new Index(index);
-
-            BuildReference<R> ref = createReference(r);
-            BuildReference<R> old = copy.byNumber.put(getNumberOf(r), ref);
-            assert old == null || old.get() == null : "tried to overwrite " + old + " with " + ref;
-
-            if (editInPlace == null)  index = copy;
-
             return r;
         } catch (IOException e) {
             LOGGER.log(Level.WARNING, "Failed to load " + dataDir, e);
@@ -747,7 +484,6 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
         return new BuildReference<>(getIdOf(r), r);
     }
 
-
     /**
      * Parses {@code R} instance from data in the specified directory.
      *
@@ -759,31 +495,22 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
      */
     protected abstract R retrieve(File dir) throws IOException;
 
+    protected abstract Class<R> getBuildClass();
+
     public synchronized boolean removeValue(R run) {
-        Index copy = copy();
-        int n = getNumberOf(run);
-        BuildReference<R> old = copy.byNumber.remove(n);
-        SortedIntList a = new SortedIntList(numberOnDisk);
-        a.removeValue(n);
-        numberOnDisk = a;
-        this.index = copy;
-
-        entrySet.clearCache();
-
-        return old != null;
+        return core.remove(getNumberOf(run)) != null;
     }
 
     /**
      * Replaces all the current loaded Rs with the given ones.
      */
-    public synchronized void reset(TreeMap<Integer, R> builds) {
-        Index index = new Index();
+    public synchronized void reset(Map<Integer, R> builds) {
+        TreeMap<Integer, BuildReference<R>> copy = new TreeMap<>();
         for (R r : builds.values()) {
-            BuildReference<R> ref = createReference(r);
-            index.byNumber.put(getNumberOf(r), ref);
+            copy.put(getNumberOf(r), createReference(r));
         }
 
-        this.index = index;
+        this.core.replaceBy(copy);
     }
 
     @Override
@@ -800,7 +527,22 @@ public abstract class AbstractLazyLoadRunMap<R> extends AbstractMap<Integer, R>
         ASC, DESC, EXACT
     }
 
-    private static final SortedMap EMPTY_SORTED_MAP = Collections.unmodifiableSortedMap(new TreeMap());
+    private class BuildReferenceMapAdapterResolver implements BuildReferenceMapAdapter.Resolver<R> {
+        @Override
+        public R resolveBuildRef(BuildReference<R> buildRef) {
+            return AbstractLazyLoadRunMap.this.resolveBuildRef(buildRef);
+        }
+
+        @Override
+        public Integer getNumberOf(R build) {
+            return AbstractLazyLoadRunMap.this.getNumberOf(build);
+        }
+
+        @Override
+        public Class<R> getBuildClass() {
+            return AbstractLazyLoadRunMap.this.getBuildClass();
+        }
+    }
 
     static final Logger LOGGER = Logger.getLogger(AbstractLazyLoadRunMap.class.getName());
 }

core/src/main/java/jenkins/model/lazy/BuildReference.java

@@ -36,13 +36,57 @@ public final class BuildReference<R> {
     private static final Logger LOGGER = Logger.getLogger(BuildReference.class.getName());
 
     final String id;
+    final int number;
     private volatile Holder<R> holder;
 
-    public BuildReference(String id, R referent) {
+    public BuildReference(String id) {
         this.id = id;
-        this.holder = findHolder(referent);
+        int num;
+        try {
+            num = Integer.parseInt(id);
+        } catch (NumberFormatException ignored) {
+            num = Integer.MAX_VALUE;
+        }
+        this.number = num;
     }
 
+    public BuildReference(String id, R referent) {
+        this(id);
+        set(referent);
+    }
+
+    /**
+     * Set referent if loaded
+     */
+    /*package*/ void set(R referent) {
+        holder = findHolder(referent);
+    }
+
+    /**
+     * check if reference marked as unloadable
+     */
+    /*package*/ boolean isUnloadable() {
+        return DefaultHolderFactory.UnloadableHolder.getInstance() == holder;
+    }
+
+    /**
+     * check if reference holder set.
+     * means there war a try to load build object and we have some result of that try
+     *
+     * @return true if there was a try to
+     */
+    /*package*/ boolean isSet() {
+        return holder != null;
+    }
+
+    /**
+     * Set referent as unloadable
+     */
+    /*package*/ void setUnloadable() {
+        holder = DefaultHolderFactory.UnloadableHolder.getInstance();
+    }
+
+
     /**
      * Gets the build if still in memory.
      * @return the actual build, or null if it has been collected
@@ -155,7 +199,7 @@ public final class BuildReference<R> {
             } else if (mode.equals("strong")) {
                 return new StrongHolder<>(referent);
             } else if (mode.equals("none")) {
-                return new NoHolder<>();
+                return NoHolder.getInstance();
             } else {
                 throw new IllegalStateException("unrecognized value of " + MODE_PROPERTY + ": " + mode);
             }
@@ -186,6 +230,32 @@ public final class BuildReference<R> {
         }
 
         private static final class NoHolder<R> implements Holder<R> {
+            static final NoHolder<?> INSTANCE = new NoHolder<>();
+
+            static <R> NoHolder<R> getInstance() {
+                //noinspection unchecked
+                return (NoHolder<R>) INSTANCE;
+            }
+
+            private NoHolder() {
+            }
+
+            @Override public R get() {
+                return null;
+            }
+        }
+
+        private static final class UnloadableHolder<R> implements Holder<R> {
+            static final UnloadableHolder<?> INSTANCE = new UnloadableHolder<>();
+
+            static <R> UnloadableHolder<R> getInstance() {
+                //noinspection unchecked
+                return (UnloadableHolder<R>) INSTANCE;
+            }
+
+            private UnloadableHolder() {
+            }
+
             @Override public R get() {
                 return null;
             }

core/src/main/java/jenkins/model/lazy/BuildReferenceMapAdapter.java

@@ -1,54 +1,61 @@
 package jenkins.model.lazy;
 
-import edu.umd.cs.findbugs.annotations.Nullable;
 import hudson.util.AdaptedIterator;
 import hudson.util.Iterators;
+import java.util.AbstractCollection;
 import java.util.AbstractMap;
-import java.util.ArrayList;
+import java.util.AbstractSet;
 import java.util.Collection;
 import java.util.Comparator;
 import java.util.Iterator;
-import java.util.LinkedHashMap;
-import java.util.List;
 import java.util.Map;
+import java.util.NavigableMap;
+import java.util.NoSuchElementException;
+import java.util.Objects;
 import java.util.Set;
 import java.util.SortedMap;
+import java.util.Spliterator;
+import java.util.Spliterators;
+import java.util.function.IntConsumer;
 
 /**
  * Take {@code SortedMap<Integer,BuildReference<R>>} and make it look like {@code SortedMap<Integer,R>}.
  *
- * When {@link BuildReference} lost the build object, we'll use {@link AbstractLazyLoadRunMap#getById(String)}
- * to obtain one.
+ * <p>
+ * When {@link BuildReference} lost the build object, we'll use {@link Resolver} to obtain one.
+ * </p>
+ *
+ * <p>
+ * By default, this adapter provides a read-only view of the underlying {@link #core} map,
+ * which may be modified externally to change the adapter's state.
+ * Support for removal operations through {@link #entrySet()}, {@link #values()},
+ * {@link #keySet()}, and their iterators can be enabled by overriding
+ * {@link #removeValue(Object)}. This method is invoked by the internal collection views
+ * to perform the actual removal logic (such as updating {@link #core} or performing other actions).
+ * </p>
+ *
+ * <p>
+ * Some operations are weakly implemented (for example, {@link #size()} may be approximate).
+ * This adapter implements {@link SortedMap}, which does not allow {@code null} keys; however,
+ * methods such as {@code get(null)} or {@code containsKey(null)} do not throw a {@link NullPointerException}
+ * and instead return {@code null} or {@code false}, respectively, indicating that the key was not found.
+ * </p>
  *
  * @author Kohsuke Kawaguchi
  */
-class BuildReferenceMapAdapter<R> implements SortedMap<Integer, R> {
-    private final AbstractLazyLoadRunMap<R> loader;
+class BuildReferenceMapAdapter<R> extends AbstractMap<Integer, R> implements SortedMap<Integer, R> {
+    private final NavigableMap<Integer, BuildReference<R>> core;
+    private final Resolver<R> resolver;
 
-    private final SortedMap<Integer, BuildReference<R>> core;
+    private final Set<Integer> keySet = new KeySetAdapter();
+    private final Collection<R> values = new ValuesAdapter();
+    private final Set<Map.Entry<Integer, R>> entrySet = new EntrySetAdapter();
 
-    BuildReferenceMapAdapter(AbstractLazyLoadRunMap<R> loader, SortedMap<Integer, BuildReference<R>> core) {
-        this.loader = loader;
+    BuildReferenceMapAdapter(NavigableMap<Integer, BuildReference<R>> core, Resolver<R> resolver) {
         this.core = core;
+        this.resolver = resolver;
     }
 
-    private R unwrap(@Nullable BuildReference<R> ref) {
-        if (ref == null)  return null;
-
-        R v = ref.get();
-        if (v == null)
-            v = loader.getById(ref.id);
-        return v;
-    }
-
-    private BuildReference<R> wrap(@Nullable R value) {
-        if (value == null)    return null;
-        return loader.createReference(value);
-    }
-
-
-
-
     @Override
     public Comparator<? super Integer> comparator() {
         return core.comparator();
@@ -56,330 +63,274 @@ class BuildReferenceMapAdapter<R> implements SortedMap<Integer, R> {
 
     @Override
     public SortedMap<Integer, R> subMap(Integer fromKey, Integer toKey) {
-        return new BuildReferenceMapAdapter<>(loader, core.subMap(fromKey, toKey));
+        return new BuildReferenceMapAdapter<>(core.subMap(fromKey, true, toKey, false), resolver);
     }
 
     @Override
     public SortedMap<Integer, R> headMap(Integer toKey) {
-        return new BuildReferenceMapAdapter<>(loader, core.headMap(toKey));
+        return new BuildReferenceMapAdapter<>(core.headMap(toKey, false), resolver);
     }
 
     @Override
     public SortedMap<Integer, R> tailMap(Integer fromKey) {
-        return new BuildReferenceMapAdapter<>(loader, core.tailMap(fromKey));
+        return new BuildReferenceMapAdapter<>(core.tailMap(fromKey, true), resolver);
     }
 
     @Override
     public Integer firstKey() {
-        return core.firstKey();
+        return keySet.stream().findFirst().orElseThrow(NoSuchElementException::new);
     }
 
     @Override
     public Integer lastKey() {
-        return core.lastKey();
+        return new BuildReferenceMapAdapter<>(core.descendingMap(), resolver).firstKey();
     }
 
     @Override
     public Set<Integer> keySet() {
-        return core.keySet();
+        return keySet;
     }
 
     @Override
     public Collection<R> values() {
-        return new CollectionAdapter(core.values());
+        return values;
     }
 
     @Override
     public Set<Entry<Integer, R>> entrySet() {
-        return new SetAdapter(core.entrySet());
-    }
-
-    @Override
-    public int size() {
-        return core.size();
+        return entrySet;
     }
 
     @Override
     public boolean isEmpty() {
-        return core.isEmpty();
+        return entrySet().isEmpty();
     }
 
     @Override
     public boolean containsKey(Object key) {
-        return core.containsKey(key);
+        BuildReference<R> ref = key instanceof Integer ? core.get(key) : null;
+        if (ref == null) {
+            return false;
+        }
+        // if found, check if value is loadable
+        if (!ref.isSet()) {
+            resolver.resolveBuildRef(ref);
+        }
+        return !ref.isUnloadable();
     }
 
     @Override
     public boolean containsValue(Object value) {
-        return core.containsValue(value); // TODO should this be core.containsValue(wrap(value))?
+        if (!resolver.getBuildClass().isInstance(value)) {
+            return false;
+        }
+        R val = resolver.getBuildClass().cast(value);
+        return val.equals(get(resolver.getNumberOf(val)));
     }
 
     @Override
     public R get(Object key) {
-        return unwrap(core.get(key));
-    }
-
-    @Override
-    public R put(Integer key, R value) {
-        return unwrap(core.put(key, wrap(value)));
+        return key instanceof Integer ? resolver.resolveBuildRef(core.get(key)) : null;
     }
 
     @Override
     public R remove(Object key) {
-        return unwrap(core.remove(key));
-    }
-
-    @Override
-    public void putAll(Map<? extends Integer, ? extends R> m) {
-        for (Entry<? extends Integer, ? extends R> e : m.entrySet())
-            put(e.getKey(), e.getValue());
-    }
-
-    @Override
-    public void clear() {
-        core.clear();
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        return core.equals(o); // TODO this is wrong
-    }
-
-    @Override
-    public int hashCode() {
-        return core.hashCode();
-    }
-
-    @Override public String toString() {
-        return new LinkedHashMap<>(this).toString();
-    }
-
-    private class CollectionAdapter implements Collection<R> {
-        private final Collection<BuildReference<R>> core;
-
-        private CollectionAdapter(Collection<BuildReference<R>> core) {
-            this.core = core;
+        R val = get(key);
+        if (val == null) {
+            return null;
         }
+        return removeValue(val) ? val : null;
+    }
 
+    protected boolean removeValue(R value) {
+        throw new UnsupportedOperationException();
+    }
+
+    private class KeySetAdapter extends AbstractSet<Integer> {
         @Override
         public int size() {
-            return core.size();
+            return BuildReferenceMapAdapter.this.size();
         }
 
         @Override
         public boolean isEmpty() {
-            return core.isEmpty();
+            return BuildReferenceMapAdapter.this.isEmpty();
         }
 
         @Override
-        public boolean contains(Object o) {
-            // TODO: to properly pass this onto core, we need to wrap o into BuildReference but also needs to figure out ID.
-            throw new UnsupportedOperationException();
+        public boolean contains(Object k) {
+            return BuildReferenceMapAdapter.this.containsKey(k);
+        }
+
+        @Override
+        public boolean remove(Object o) {
+            return BuildReferenceMapAdapter.this.remove(o) != null;
+        }
+
+        @Override
+        public Iterator<Integer> iterator() {
+            return new AdaptedIterator<>(BuildReferenceMapAdapter.this.entrySet().iterator()) {
+                @Override
+                protected Integer adapt(Entry<Integer, R> e) {
+                    return e.getKey();
+                }
+            };
+        }
+
+        @Override
+        public Spliterator<Integer> spliterator() {
+            return new Spliterators.AbstractIntSpliterator(Long.MAX_VALUE,
+                    Spliterator.DISTINCT | Spliterator.ORDERED | Spliterator.SORTED) {
+                private final Iterator<Integer> it = KeySetAdapter.this.iterator();
+
+                @Override
+                public boolean tryAdvance(IntConsumer action) {
+                    Objects.requireNonNull(action);
+                    if (it.hasNext()) {
+                        action.accept(it.next());
+                        return true;
+                    }
+                    return false;
+                }
+
+                @Override
+                public Comparator<? super Integer> getComparator() {
+                    return BuildReferenceMapAdapter.this.comparator();
+                }
+            };
+        }
+    }
+
+    private class ValuesAdapter extends AbstractCollection<R> {
+        @Override
+        public int size() {
+            return BuildReferenceMapAdapter.this.size();
+        }
+
+        @Override
+        public boolean isEmpty() {
+            return BuildReferenceMapAdapter.this.isEmpty();
+        }
+
+        @Override
+        public boolean contains(Object v) {
+            return BuildReferenceMapAdapter.this.containsValue(v);
+        }
+
+        @Override
+        public boolean remove(Object o) {
+            return resolver.getBuildClass().isInstance(o) &&
+                    BuildReferenceMapAdapter.this.removeValue(resolver.getBuildClass().cast(o));
         }
 
         @Override
         public Iterator<R> iterator() {
-            // silently drop null, as if we didn't have them in this collection in the first place
-            // this shouldn't be indistinguishable from concurrent modifications to the collection
-            return Iterators.removeNull(new AdaptedIterator<>(core.iterator()) {
+            return new AdaptedIterator<>(BuildReferenceMapAdapter.this.entrySet().iterator()) {
                 @Override
-                protected R adapt(BuildReference<R> ref) {
-                    return unwrap(ref);
+                protected R adapt(Entry<Integer, R> e) {
+                    return e.getValue();
                 }
-            });
+            };
         }
 
         @Override
-        public Object[] toArray() {
-            List<Object> list = new ArrayList<>(size());
-            for (var e : this) {
-                list.add(e);
-            }
-            return list.toArray();
-        }
-
-        @Override
-        public <T> T[] toArray(T[] a) {
-            return new ArrayList<>(this).toArray(a);
-        }
-
-        @Override
-        public boolean add(R value) {
-            return core.add(wrap(value));
-        }
-
-        @Override
-        public boolean remove(Object o) {
-//            return core.remove(o);
-            // TODO: to properly pass this onto core, we need to wrap o into BuildReference but also needs to figure out ID.
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public boolean containsAll(Collection<?> c) {
-            for (Object o : c) {
-                if (!contains(o))
-                    return false;
-            }
-            return true;
-        }
-
-        @Override
-        public boolean addAll(Collection<? extends R> c) {
-            boolean b = false;
-            for (R r : c) {
-                b |= add(r);
-            }
-            return b;
-        }
-
-        @Override
-        public boolean removeAll(Collection<?> c) {
-            boolean b = false;
-            for (Object o : c) {
-                b |= remove(o);
-            }
-            return b;
-        }
-
-        @Override
-        public boolean retainAll(Collection<?> c) {
-            // TODO: to properly pass this onto core, we need to wrap o into BuildReference but also needs to figure out ID.
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public void clear() {
-            core.clear();
-        }
-
-        @Override
-        public boolean equals(Object o) {
-            return core.equals(o);
-        }
-
-        @Override
-        public int hashCode() {
-            return core.hashCode();
+        public Spliterator<R> spliterator() {
+            return Spliterators.spliteratorUnknownSize(iterator(), Spliterator.DISTINCT | Spliterator.ORDERED);
         }
     }
 
-    private class SetAdapter implements Set<Entry<Integer, R>> {
-        private final Set<Entry<Integer, BuildReference<R>>> core;
-
-        private SetAdapter(Set<Entry<Integer, BuildReference<R>>> core) {
-            this.core = core;
-        }
-
+    private class EntrySetAdapter extends AbstractSet<Entry<Integer, R>> {
         @Override
         public int size() {
-            return core.size();
+            return BuildReferenceMapAdapter.this.core.size();
         }
 
         @Override
         public boolean isEmpty() {
-            return core.isEmpty();
+            return this.stream().findFirst().isEmpty();
         }
 
         @Override
         public boolean contains(Object o) {
-            // TODO: to properly pass this onto core, we need to wrap o into BuildReference but also needs to figure out ID.
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public Iterator<Entry<Integer, R>> iterator() {
-            return Iterators.removeNull(new AdaptedIterator<>(core.iterator()) {
-                @Override
-                protected Entry<Integer, R> adapt(Entry<Integer, BuildReference<R>> e) {
-                    return _unwrap(e);
-                }
-            });
-        }
-
-        @Override
-        public Object[] toArray() {
-            List<Object> list = new ArrayList<>(size());
-            for (var e : this) {
-                list.add(e);
+            if (o instanceof Map.Entry<?, ?> e && e.getKey() instanceof Integer key) {
+                return e.getValue() != null && e.getValue().equals(BuildReferenceMapAdapter.this.get(key));
             }
-            return list.toArray();
-        }
-
-        @Override
-        public <T> T[] toArray(T[] a) {
-            return new ArrayList<>(this).toArray(a);
-        }
-
-        @Override
-        public boolean add(Entry<Integer, R> value) {
-            return core.add(_wrap(value));
+            return false;
         }
 
         @Override
         public boolean remove(Object o) {
-//            return core.remove(o);
-            // TODO: to properly pass this onto core, we need to wrap o into BuildReference but also needs to figure out ID.
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public boolean containsAll(Collection<?> c) {
-            for (Object o : c) {
-                if (!contains(o))
-                    return false;
+            if (o instanceof Map.Entry<?, ?> e) {
+                return resolver.getBuildClass().isInstance(e.getValue()) &&
+                        BuildReferenceMapAdapter.this.removeValue(resolver.getBuildClass().cast(e.getValue()));
             }
-            return true;
+            return false;
         }
 
         @Override
-        public boolean addAll(Collection<? extends Entry<Integer, R>> c) {
-            boolean b = false;
-            for (Entry<Integer, R> r : c) {
-                b |= add(r);
-            }
-            return b;
+        public Iterator<Entry<Integer, R>> iterator() {
+            return new Iterator<>() {
+                private Entry<Integer, R> current;
+                private final Iterator<Entry<Integer, R>> it = Iterators.removeNull(Iterators.map(
+                        BuildReferenceMapAdapter.this.core.entrySet().iterator(), coreEntry -> {
+                            R v = BuildReferenceMapAdapter.this.resolver.resolveBuildRef(coreEntry.getValue());
+                            return v == null ? null : new AbstractMap.SimpleEntry<>(coreEntry.getKey(), v);
+                        }));
+
+                @Override
+                public boolean hasNext() {
+                    return it.hasNext();
+                }
+
+                @Override
+                public Entry<Integer, R> next() {
+                    return current = it.next();
+                }
+
+                @Override
+                public void remove() {
+                    if (current == null) {
+                        throw new IllegalStateException();
+                    }
+                    BuildReferenceMapAdapter.this.removeValue(current.getValue());
+                }
+            };
         }
 
         @Override
-        public boolean removeAll(Collection<?> c) {
-            boolean b = false;
-            for (Object o : c) {
-                b |= remove(o);
-            }
-            return b;
-        }
-
-        @Override
-        public boolean retainAll(Collection<?> c) {
-            // TODO: to properly pass this onto core, we need to wrap o into BuildReference but also needs to figure out ID.
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public void clear() {
-            core.clear();
-        }
-
-        @Override
-        public boolean equals(Object o) {
-            return core.equals(o);
-        }
-
-        @Override
-        public int hashCode() {
-            return core.hashCode();
-        }
-
-        private Entry<Integer, BuildReference<R>> _wrap(Entry<Integer, R> e) {
-            return new AbstractMap.SimpleEntry<>(e.getKey(), wrap(e.getValue()));
-        }
-
-        private Entry<Integer, R> _unwrap(Entry<Integer, BuildReference<R>> e) {
-            R v = unwrap(e.getValue());
-            if (v == null)
-                return null;
-            return new AbstractMap.SimpleEntry<>(e.getKey(), v);
+        public Spliterator<Map.Entry<Integer, R>> spliterator() {
+            return Spliterators.spliteratorUnknownSize(iterator(), Spliterator.DISTINCT | Spliterator.ORDERED);
         }
     }
+
+    /**
+     * An interface for resolving build references into actual build instances
+     * and extracting basic metadata from them.
+     **/
+    public interface Resolver<R> {
+
+        /**
+         * Resolves the given build reference into an actual build instance.
+         *
+         * @param buildRef the reference to a build to resolve, can be {@code null}
+         * @return the resolved build instance, or {@code null} if the reference is {@code null}
+         *      or could not be resolved
+         */
+        R resolveBuildRef(BuildReference<R> buildRef);
+
+        /**
+         * Returns the build number associated with the given build instance.
+         *
+         * @param build the build instance, cannot be null
+         * @return the build number
+         */
+        Integer getNumberOf(R build);
+
+        /**
+         * Returns the class of the build type handled by this resolver.
+         *
+         * @return the {@link Class} of the build type {@code R}
+         */
+        Class<R> getBuildClass();
+    }
 }

core/src/main/java/jenkins/model/lazy/LazyBuildMixIn.java

@@ -47,6 +47,7 @@ import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
+import java.util.TreeMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import org.kohsuke.accmod.Restricted;
@@ -128,13 +129,15 @@ public abstract class LazyBuildMixIn<JobT extends Job<JobT, RunT> & Queue.Task &
         }
         if (currentBuilds != null) {
             // if we are reloading, keep all those that are still building intact
+            TreeMap<Integer, RunT> stillBuildingBuilds = new TreeMap<>();
             for (RunT r : currentBuilds.getLoadedBuilds().values()) {
                 if (r.isBuilding()) {
                     // Do not use RunMap.put(Run):
-                    _builds.put(r.getNumber(), r);
+                    stillBuildingBuilds.put(r.getNumber(), r);
                     LOGGER.log(Level.FINE, "keeping reloaded {0}", r);
                 }
             }
+            _builds.putAll(stillBuildingBuilds);
         }
         this.builds = _builds;
     }
@@ -145,6 +148,11 @@ public abstract class LazyBuildMixIn<JobT extends Job<JobT, RunT> & Queue.Task &
             public RunT create(File dir) throws IOException {
                 return loadBuild(dir);
             }
+
+            @Override
+            public Class<RunT> getBuildClass() {
+                return LazyBuildMixIn.this.getBuildClass();
+            }
         });
         return r;
     }

core/src/main/java/jenkins/model/lazy/LazyLoadRunMapEntrySet.java

@@ -1,125 +0,0 @@
-package jenkins.model.lazy;
-
-import java.util.AbstractMap;
-import java.util.AbstractSet;
-import java.util.Iterator;
-import java.util.Map;
-import java.util.NoSuchElementException;
-import java.util.Set;
-import java.util.Spliterator;
-import java.util.Spliterators;
-import jenkins.model.lazy.AbstractLazyLoadRunMap.Direction;
-
-/**
- * Set that backs {@link AbstractLazyLoadRunMap#entrySet()}.
- *
- * @author Kohsuke Kawaguchi
- */
-class LazyLoadRunMapEntrySet<R> extends AbstractSet<Map.Entry<Integer, R>> {
-    private final AbstractLazyLoadRunMap<R> owner;
-
-    /**
-     * Lazily loaded all entries.
-     */
-    private Set<Map.Entry<Integer, R>> all;
-
-    LazyLoadRunMapEntrySet(AbstractLazyLoadRunMap<R> owner) {
-        this.owner = owner;
-    }
-
-    private synchronized Set<Map.Entry<Integer, R>> all() {
-        if (all == null)
-            all = new BuildReferenceMapAdapter<>(owner, owner.all()).entrySet();
-        return all;
-    }
-
-    synchronized void clearCache() {
-        all = null;
-    }
-
-    @Override
-    public int size() {
-        return all().size();
-    }
-
-    @Override
-    public boolean isEmpty() {
-        return owner.newestBuild() == null;
-    }
-
-    @Override
-    public boolean contains(Object o) {
-        if (o instanceof Map.Entry) {
-            Map.Entry<?, ?> e = (Map.Entry<?, ?>) o;
-            Object k = e.getKey();
-            if (k instanceof Integer) {
-                return owner.getByNumber((Integer) k).equals(e.getValue());
-            }
-        }
-        return false;
-    }
-
-    @Override
-    public Iterator<Map.Entry<Integer, R>> iterator() {
-        return new Iterator<>() {
-            R last = null;
-            R next = owner.newestBuild();
-
-            @Override
-            public boolean hasNext() {
-                return next != null;
-            }
-
-            @Override
-            public Map.Entry<Integer, R> next() {
-                last = next;
-                if (last != null) {
-                    next = owner.search(owner.getNumberOf(last) - 1, Direction.DESC);
-                } else
-                    throw new NoSuchElementException();
-                return entryOf(last);
-            }
-
-            private Map.Entry<Integer, R> entryOf(R r) {
-                return new AbstractMap.SimpleImmutableEntry<>(owner.getNumberOf(r), r);
-            }
-
-            @Override
-            public void remove() {
-                if (last == null)
-                    throw new UnsupportedOperationException();
-                owner.removeValue(last);
-            }
-        };
-    }
-
-    @Override
-    public Spliterator<Map.Entry<Integer, R>> spliterator() {
-        return Spliterators.spliteratorUnknownSize(
-                iterator(), Spliterator.DISTINCT | Spliterator.ORDERED);
-    }
-
-    @Override
-    public Object[] toArray() {
-        return all().toArray();
-    }
-
-    @Override
-    public <T> T[] toArray(T[] a) {
-        return all().toArray(a);
-    }
-
-    @Override
-    public boolean add(Map.Entry<Integer, R> integerREntry) {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public boolean remove(Object o) {
-        if (o instanceof Map.Entry) {
-            Map.Entry e = (Map.Entry) o;
-            return owner.removeValue((R) e.getValue());
-        }
-        return false;
-    }
-}

core/src/main/java/jenkins/model/lazy/SortedIntList.java

@@ -1,156 +0,0 @@
-/*
- * The MIT License
- *
- * Copyright (c) 2012, CloudBees, Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-package jenkins.model.lazy;
-
-import java.util.AbstractList;
-import java.util.Arrays;
-
-/**
- * {@code ArrayList<Integer>} that uses {@code int} for storage.
- *
- * Plus a number of binary-search related methods that assume the array is sorted in the ascending order.
- *
- * @author Kohsuke Kawaguchi
- */
-class SortedIntList extends AbstractList<Integer> {
-    private int[] data;
-    private int size;
-
-    SortedIntList(int capacity) {
-        this.data = new int[capacity];
-        this.size = 0;
-    }
-
-    /**
-     * Internal copy constructor.
-     */
-    SortedIntList(SortedIntList that) {
-        this.data = new int[that.size + 8];
-        System.arraycopy(that.data, 0, this.data, 0,
-                         that.size);
-        this.size = that.size;
-    }
-
-    /**
-     * Binary search to find the position of the given string.
-     *
-     * @return
-     *      -(insertionPoint+1) if the exact string isn't found.
-     *      That is, -1 means the probe would be inserted at the very beginning.
-     */
-    public int find(int probe) {
-        return Arrays.binarySearch(data, 0, size, probe);
-    }
-
-    @Override
-    public boolean contains(Object o) {
-        return o instanceof Integer && contains(((Integer) o).intValue());
-    }
-
-    public boolean contains(int i) {
-        return find(i) >= 0;
-    }
-
-    @Override
-    public Integer get(int index) {
-        if (size <= index)    throw new IndexOutOfBoundsException();
-        return data[index];
-    }
-
-    @Override
-    public int size() {
-        return size;
-    }
-
-    public int max() {
-        return size > 0 ? data[size - 1] : 0;
-    }
-
-    @Override
-    public boolean add(Integer i) {
-        return add(i.intValue());
-    }
-
-    public boolean add(int i) {
-        ensureCapacity(size + 1);
-        data[size++] = i;
-        return true;
-    }
-
-    private void ensureCapacity(int i) {
-        if (data.length < i) {
-            int[] r = new int[Math.max(data.length * 2, i)];
-            System.arraycopy(data, 0, r, 0, size);
-            data = r;
-        }
-    }
-
-    /**
-     * Finds the index of the entry lower than v.
-     */
-    public int lower(int v) {
-        return Boundary.LOWER.apply(find(v));
-    }
-
-    /**
-     * Finds the index of the entry greater than v.
-     */
-    public int higher(int v) {
-        return Boundary.HIGHER.apply(find(v));
-    }
-
-    /**
-     * Finds the index of the entry lower or equal to v.
-     */
-    public int floor(int v) {
-        return Boundary.FLOOR.apply(find(v));
-    }
-
-    /**
-     * Finds the index of the entry greater or equal to v.
-     */
-    public int ceil(int v) {
-        return Boundary.CEIL.apply(find(v));
-    }
-
-    public boolean isInRange(int idx) {
-        return 0 <= idx && idx < size;
-    }
-
-    public void sort() {
-        Arrays.sort(data, 0, size);
-    }
-
-    public void copyInto(int[] dest) {
-        System.arraycopy(data, 0, dest, 0, size);
-    }
-
-    public void removeValue(int n) {
-        int idx = find(n);
-        if (idx < 0)  return;
-        System.arraycopy(data, idx + 1, data, idx, size - (idx + 1));
-        size--;
-    }
-}

core/src/main/java/jenkins/model/lazy/SortedList.java

@@ -1,135 +0,0 @@
-/*
- * The MIT License
- *
- * Copyright (c) 2012, CloudBees, Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-package jenkins.model.lazy;
-
-import java.util.AbstractList;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-/**
- * {@link List} decorator that provides a number of binary-search related methods
- * by assuming that the array is sorted in the ascending order.
- *
- * @author Kohsuke Kawaguchi
- */
-class SortedList<T extends Comparable<T>> extends AbstractList<T> {
-    private List<T> data;
-
-    SortedList(List<T> data) {
-        this.data = new ArrayList<>(data);
-        assert isSorted();
-    }
-
-    /**
-     * Binary search to find the position of the given string.
-     *
-     * @return
-     *      -(insertionPoint+1) if the exact string isn't found.
-     *      That is, -1 means the probe would be inserted at the very beginning.
-     */
-    public int find(T probe) {
-        return Collections.binarySearch(data, probe);
-    }
-
-    @Override
-    public boolean contains(Object o) {
-        return find((T) o) >= 0;
-    }
-
-    @Override
-    public T get(int idx) {
-        return data.get(idx);
-    }
-
-    @Override
-    public int size() {
-        return data.size();
-    }
-
-    @Override
-    public T remove(int index) {
-        return data.remove(index);
-    }
-
-    @Override
-    public boolean remove(Object o) {
-        return data.remove(o);
-    }
-
-    /**
-     * Finds the index of the entry lower than v.
-     *
-     * @return
-     *      return value will be in the [-1,size) range
-     */
-    public int lower(T v) {
-        return Boundary.LOWER.apply(find(v));
-    }
-
-    /**
-     * Finds the index of the entry greater than v.
-     *
-     * @return
-     *      return value will be in the [0,size] range
-     */
-    public int higher(T v) {
-        return Boundary.HIGHER.apply(find(v));
-    }
-
-    /**
-     * Finds the index of the entry lower or equal to v.
-     *
-     * @return
-     *      return value will be in the [-1,size) range
-     */
-    public int floor(T v) {
-        return Boundary.FLOOR.apply(find(v));
-    }
-
-    /**
-     * Finds the index of the entry greater or equal to v.
-     *
-     * @return
-     *      return value will be in the [0,size] range
-     */
-    public int ceil(T v) {
-        return Boundary.CEIL.apply(find(v));
-    }
-
-    public boolean isInRange(int idx) {
-        return 0 <= idx && idx < data.size();
-    }
-
-    private boolean isSorted() {
-        for (int i = 1; i < data.size(); i++) {
-            if (data.get(i).compareTo(data.get(i - 1)) < 0) {
-                return false;
-            }
-        }
-        return true;
-    }
-
-}

core/src/main/java/jenkins/model/queue/ITask.java

@@ -26,15 +26,15 @@ package jenkins.model.queue;
 
 import edu.umd.cs.findbugs.annotations.CheckForNull;
 import hudson.model.Item;
-import hudson.model.ModelObject;
 import hudson.security.AccessControlled;
+import jenkins.model.FullyNamedModelObject;
 
 /**
  * A task that can be displayed in the executors widget.
  *
  * @since 2.480
  */
-public interface ITask extends ModelObject {
+public interface ITask extends FullyNamedModelObject {
     /**
      * @return {@code true} if the current user can cancel the current task.
      *

core/src/main/java/jenkins/model/queue/QueueItem.java

@@ -3,9 +3,9 @@ package jenkins.model.queue;
 import edu.umd.cs.findbugs.annotations.CheckForNull;
 import edu.umd.cs.findbugs.annotations.NonNull;
 import hudson.model.Cause;
-import hudson.model.ModelObject;
 import hudson.model.Queue;
 import hudson.model.Run;
+import jenkins.model.FullyNamedModelObject;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.Beta;
 
@@ -14,7 +14,7 @@ import org.kohsuke.accmod.restrictions.Beta;
  * @since 2.405
  */
 @Restricted(Beta.class)
-public interface QueueItem extends ModelObject {
+public interface QueueItem extends FullyNamedModelObject {
     /**
      * @return true if the item is starving for an executor for too long.
      */
@@ -73,6 +73,15 @@ public interface QueueItem extends ModelObject {
     @CheckForNull
     @Override
     default String getDisplayName() {
+        // TODO review usage of this method and replace with getFullDisplayName() where appropriate
+        return getTask().getFullDisplayName();
+    }
+
+    /**
+     * @return the full display name for this queue item; by default, {@link Queue.Task#getFullDisplayName()}
+     */
+    @Override
+    default String getFullDisplayName() {
         return getTask().getFullDisplayName();
     }
 }

core/src/main/java/jenkins/util/URLClassLoader2.java

@@ -2,6 +2,8 @@ package jenkins.util;
 
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.util.Objects;
+import java.util.concurrent.atomic.AtomicInteger;
 import jenkins.ClassLoaderReflectionToolkit;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
@@ -12,6 +14,10 @@ import org.kohsuke.accmod.restrictions.NoExternalUse;
  */
 @Restricted(NoExternalUse.class)
 public class URLClassLoader2 extends URLClassLoader implements JenkinsClassLoader {
+    private static final AtomicInteger NEXT_INSTANCE_NUMBER = new AtomicInteger(0);
+
+    private final String lockObjectPrefixName = String.format(
+            "%s@%x-loadClassLock:", URLClassLoader2.class.getName(), NEXT_INSTANCE_NUMBER.getAndIncrement());
 
     static {
         registerAsParallelCapable();
@@ -69,8 +75,25 @@ public class URLClassLoader2 extends URLClassLoader implements JenkinsClassLoade
         return super.findLoadedClass(name);
     }
 
+    /**
+     * Replace the JDK's per-name lock map with a GC-collectable lock object. This is a workaround
+     * for JDK-8005233. When JDK-8005233 is resolved, this should be deleted. See also the
+     * discussion in <a
+     * href="https://mail.openjdk.org/pipermail/core-libs-dev/2025-May/146392.html">this OpenJDK
+     * thread</a>.
+     *
+     * <p>Parallel-capable {@link ClassLoader} implementations keep a distinct lock object per class
+     * name indefinitely, which can retain huge maps when there are many misses. Returning an
+     * interned {@link String} keyed by this loader and the class name preserves mutual exclusion
+     * for a given (loader, name) pair but allows the JVM to reclaim the lock when no longer
+     * referenced. Interned Strings are heap objects and GC-eligible on modern JDKs (7+).
+     *
+     * @param className the binary name of the class being loaded (must not be null)
+     * @return a lock object unique to this classloader/class pair
+     */
     @Override
     public Object getClassLoadingLock(String className) {
-        return super.getClassLoadingLock(className);
+        Objects.requireNonNull(className);
+        return (lockObjectPrefixName + className).intern();
     }
 }

core/src/main/java/org/acegisecurity/util/FieldUtils.java

@@ -24,36 +24,70 @@
 
 package org.acegisecurity.util;
 
+import edu.umd.cs.findbugs.annotations.NonNull;
 import java.lang.reflect.Field;
 
 /**
- * @deprecated use {@link org.apache.commons.lang.reflect.FieldUtils}
+ * @deprecated Add a dependency to commons-lang3-api plugin and use {@code org.apache.commons.lang3.reflect.FieldUtils}
  */
 @Deprecated
 public final class FieldUtils {
 
-    public static Object getProtectedFieldValue(String protectedField, Object object) {
+    public static Object getProtectedFieldValue(@NonNull String protectedField, @NonNull Object object) {
         try {
-            return org.apache.commons.lang.reflect.FieldUtils.readField(object, protectedField, true);
+            Field field = getField(object.getClass(), protectedField);
+            return field.get(object);
         } catch (IllegalAccessException x) {
             throw new RuntimeException(x);
         }
     }
 
-    public static void setProtectedFieldValue(String protectedField, Object object, Object newValue) {
+    public static void setProtectedFieldValue(@NonNull String protectedField, @NonNull Object object, @NonNull Object newValue) {
         try {
-            // acgegi would silently fail to write to final fields
-            // FieldUtils.writeField(Object, field, true) only sets accessible on *non* public fields
-            // and then fails with IllegalAccessException (even if you make the field accessible in the interim!
-            // for backwards compatability we need to use a few steps
-            Field field = org.apache.commons.lang.reflect.FieldUtils.getField(object.getClass(), protectedField, true);
-            field.setAccessible(true);
+            Field field = getField(object.getClass(), protectedField);
             field.set(object, newValue);
-        } catch (Exception x) {
+        } catch (IllegalAccessException x) {
             throw new RuntimeException(x);
         }
     }
 
+    /**
+     * Return the field with the given name from the class or its superclasses.
+     * If the field is not found, an {@link IllegalArgumentException} is thrown.
+     *
+     * @param clazz the class to search for the field
+     * @param fieldName the name of the field to find
+     * @return the {@link Field} object representing the field
+     * @throws IllegalArgumentException if the field is not found
+     */
+    private static Field getField(@NonNull final Class<?> clazz, @NonNull final String fieldName) {
+        // Check class and its superclasses
+        Class<?> current = clazz;
+        while (current != null) {
+            try {
+                Field field = current.getDeclaredField(fieldName);
+                field.setAccessible(true);
+                return field;
+            } catch (NoSuchFieldException e) {
+                // Continue to check superclass
+            }
+            current = current.getSuperclass();
+        }
+
+        // Check interfaces
+        for (Class<?> iface : clazz.getInterfaces()) {
+            try {
+                Field field = iface.getDeclaredField(fieldName);
+                field.setAccessible(true);
+                return field;
+            } catch (NoSuchFieldException e) {
+                // Continue to check next interface
+            }
+        }
+
+        throw new IllegalArgumentException("Field '" + fieldName + "' not found in class " + clazz.getName());
+    }
+
     // TODO other methods as needed
 
     private FieldUtils() {}

core/src/main/resources/hudson/model/AllView/noJob_pl.properties

@@ -1,6 +1,6 @@
 # The MIT License
 #
-# Copyright (c) 2004-2019, Sun Microsystems, Inc., Damian Szczepanik
+# Copyright (c) 2004-2025, Sun Microsystems, Inc., Damian Szczepanik
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -20,3 +20,10 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 Welcome\ to\ Jenkins!=Witamy w Jenkinsie!
+noJobDescription=To jest miejsce, gdzie projekty Jenkinsa będą wyświetlane. Aby rozpocząć, możesz skonfigurować rozproszone zadania albo zacząć budować swoje oprogramowanie.
+setUpDistributedBuilds=Skonfiguruj rozproszone zadania
+setUpAgent=Skonfiguruj agenta
+setUpCloud=Skonfiguruj chmurę
+learnMoreDistributedBuilds=Dowiedz się więcej o rozproszonych zadaniach
+startBuilding=Zacznij budować swoje oprogramowanie
+createJob=Utwórz projekt

core/src/main/resources/hudson/model/BooleanParameterValue/value.jelly

@@ -28,6 +28,7 @@ THE SOFTWARE.
 	xmlns:i="jelly:fmt" xmlns:p="/lib/hudson/project">
     <j:set var="escapeEntryTitleAndDescription" value="false"/>
     <f:entry description="${it.formattedDescription}">
-        <f:checkbox title="${h.escape(it.name)}" name="value" checked="${it.value}" readonly="true" />
+      <j:set var="readOnlyMode" value="true"/>
+      <f:checkbox title="${h.escape(it.name)}" name="value" checked="${it.value}"/>
     </f:entry>
 </j:jelly>

core/src/main/resources/hudson/model/Messages.properties

@@ -199,8 +199,7 @@ LabelExpression.LabelLink=<a href="{0}{2}">Label {1}</a> matches {3,choice,0#no
 LabelExpression.NoMatch=No agent/cloud matches this label expression.
 LabelExpression.NoMatch_DidYouMean=No agent/cloud matches this label expression. Did you mean ‘{1}’ instead of ‘{0}’?
 ManageJenkinsAction.DisplayName=Manage Jenkins
-ManageJenkinsAction.notification={0} notification
-ManageJenkinsAction.notifications={0} notifications
+ManageJenkinsAction.notifications=One or more notifications
 MultiStageTimeSeries.EMPTY_STRING=
 ParametersDefinitionProperty.BuildButtonText=Build
 Queue.AllNodesOffline=All nodes of label ‘{0}’ are offline

core/src/main/resources/hudson/model/ParametersAction/index.jelly

@@ -35,6 +35,7 @@ THE SOFTWARE.
     <l:main-panel>
 	  <t:buildCaption it="${build}">${title}</t:buildCaption>
       <j:set var="escapeEntryTitleAndDescription" value="true" /> <!-- SECURITY-353 defense unless overridden -->
+      <j:set var="readOnlyMode" value="true"/>
       <j:forEach var="parameterValue" items="${it.parameters}">
 	    <st:include it="${parameterValue}" page="value.jelly" />
       </j:forEach>

core/src/main/resources/hudson/model/Run/configure_pl.properties

@@ -1,6 +1,6 @@
 # The MIT License
 #
-# Copyright (c) 2004-2010, Sun Microsystems, Inc.
+# Copyright (c) 2004-2025, Sun Microsystems, Inc.
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -24,3 +24,4 @@ Description=Opis
 DisplayName=Wyświetlana nazwa
 LOADING=ŁADOWANIE
 Save=Zapisz
+Edit\ Build\ Information=Edycja informacji o zadaniu

core/src/main/resources/hudson/model/Run/console_pl.properties

@@ -1,6 +1,6 @@
 # The MIT License
 #
-# Copyright (c) 2004-2016, Kohsuke Kawaguchi, Sun Microsystems, Inc., and a number of other of contributors
+# Copyright (c) 2004-2025, Kohsuke Kawaguchi, Sun Microsystems, Inc., and a number of other of contributors
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -21,4 +21,7 @@
 # THE SOFTWARE.
 
 Console\ Output=Logi konsoli
+Download=Pobierz
+Copy=Kopiuj
 skipSome=Pominięto {0,number,integer} KB.. <a href="{1}">Pokaż wszystko</a>
+View\ as\ plain\ text=Wyświetl bez formatowania

core/src/main/resources/hudson/model/StringParameterValue/value.jelly

@@ -24,10 +24,11 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define"
-	xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form"
-	xmlns:i="jelly:fmt" xmlns:p="/lib/hudson/project">
-        <j:set var="escapeEntryTitleAndDescription" value="false"/>
-        <f:entry title="${h.escape(it.name)}" description="${it.formattedDescription}">
-		<f:textbox name="value" value="${it.value}" readonly="true" />
-	</f:entry>
+         xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form"
+         xmlns:i="jelly:fmt" xmlns:p="/lib/hudson/project">
+  <j:set var="escapeEntryTitleAndDescription" value="false"/>
+  <f:entry title="${h.escape(it.name)}" description="${it.formattedDescription}">
+    <j:set var="readOnlyMode" value="true"/>
+    <f:textbox name="value" value="${it.value}"/>
+  </f:entry>
 </j:jelly>

core/src/main/resources/hudson/model/TextParameterValue/value.jelly

@@ -26,8 +26,9 @@ THE SOFTWARE.
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define"
 	xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form"
 	xmlns:i="jelly:fmt" xmlns:p="/lib/hudson/project">
-        <j:set var="escapeEntryTitleAndDescription" value="false"/>
-        <f:entry title="${h.escape(it.name)}" description="${it.formattedDescription}">
-		<f:textarea name="value" value="${it.value}" readonly="readonly" />
-	</f:entry>
+    <j:set var="escapeEntryTitleAndDescription" value="false"/>
+    <f:entry title="${h.escape(it.name)}" description="${it.formattedDescription}">
+      <j:set var="readOnlyMode" value="true"/>
+      <f:textarea name="value" value="${it.value}"/>
+    </f:entry>
 </j:jelly>

core/src/main/resources/hudson/model/User/app-bar.jelly

@@ -0,0 +1,27 @@
+<!--
+The MIT License
+
+Copyright (c) 2025 Jan Faracik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+-->
+<?jelly escape-by-default='true'?>
+<j:jelly xmlns:j="jelly:core" xmlns:l="/lib/layout">
+  <l:app-bar title="${it.fullName}" icon="${h.getUserAvatar(it, '96x96')}" />
+</j:jelly>

core/src/main/resources/hudson/model/User/builds.jelly

@@ -27,9 +27,7 @@ THE SOFTWARE.
     <st:include page="sidepanel.jelly" />
     <l:breadcrumb title="${%Builds}" />
     <l:main-panel>
-      <h1>
-        ${%title(it)}
-      </h1>
+      <l:app-bar title="${%Builds}" />
 
       <t:buildListTable builds="${it.builds}"/>
     </l:main-panel>

core/src/main/resources/hudson/model/User/index.jelly

@@ -28,12 +28,7 @@ THE SOFTWARE.
     <!-- no need for additional breadcrumb here as we're on an index page already including breadcrumb -->
     <l:main-panel>
       <div class="jenkins-app-bar">
-        <div class="jenkins-app-bar__content jenkins-build-caption">
-          <l:icon src="${h.getUserAvatar(it, '96x96')}" class="jenkins-avatar" />
-          <h1>
-            ${it.fullName}
-          </h1>
-        </div>
+        <div class="jenkins-app-bar__content" />
         <div class="jenkins-app-bar__controls">
           <t:editDescriptionButton permission="${app.ADMINISTER}"/>
         </div>

core/src/main/resources/hudson/model/User/sidepanel.jelly

@@ -30,8 +30,10 @@ THE SOFTWARE.
 <j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form" xmlns:i="jelly:fmt">
   <l:header />
   <l:side-panel>
+    <st:include page="app-bar.jelly" />
+
     <l:tasks>
-      <l:task contextMenu="false" href="${rootURL}/${it.url}/" icon="symbol-person-circle" title="${%Status}"/>
+      <l:task contextMenu="false" href="${rootURL}/${it.url}/" icon="symbol-person" title="${%Profile}"/>
       <l:task href="${rootURL}/${it.url}/builds" icon="symbol-build-history" title="${%Builds}"/>
       <t:actions actions="${it.propertyActions}"/>
       <t:actions actions="${it.transientActions}"/>

core/src/main/resources/hudson/model/User/sidepanel_pl.properties

@@ -1,6 +1,6 @@
 # The MIT License
 #
-# Copyright (c) 2004-2016, Kohsuke Kawaguchi, Sun Microsystems, Inc., and a number of other of contributors
+# Copyright (c) 2004-2025, Kohsuke Kawaguchi, Sun Microsystems, Inc., and a number of other of contributors
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -25,3 +25,4 @@ Configure=Konfiguracja
 Delete=Usuń
 People=Użytkownicy
 Status=Status
+Profile=Profil

core/src/main/resources/hudson/model/View/newJob_pl.properties

@@ -1,6 +1,6 @@
 # The MIT License
 #
-# Copyright (c) 2004-2016, Kohsuke Kawaguchi, Sun Microsystems, Inc., and a number of other of contributors
+# Copyright (c) 2004-2025, Kohsuke Kawaguchi, Sun Microsystems, Inc., and a number of other of contributors
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -25,6 +25,7 @@ ItemName.help=Pole wymagane
 ItemName.label=Podaj nazwę projektu
 ItemName.validation.required=To pole nie może być puste, podaj nazwę projektu
 ItemType.validation.required=Wybierz rodzaj projektu
+ItemType.label=Wybierz rodzaj projektu
 CopyOption.placeholder=Podaj nazwę
 CopyOption.description=Jeśli chcesz stworzyć nowy projekt na podstawie istniejącego, możesz użyć tej opcji:
 CopyOption.label=Kopiuj z

core/src/main/resources/hudson/model/View/sidepanel.jelly

@@ -35,6 +35,9 @@ THE SOFTWARE.
     <link rel="alternate" title="Jenkins:${it.viewName} (failed builds) (RSS 2.0)" href="${rootURL}/${it.url}rssFailed?flavor=rss20" type="application/rss+xml" />
   </l:header>
   <l:side-panel>
+    <!-- Display the user's name for their views -->
+    <st:include page="app-bar.jelly" it="${it.owner.user}" optional="true" />
+
     <l:tasks>
       <st:include page="tasks-top.jelly" it="${it.owner}" optional="true" />
 

core/src/main/resources/hudson/model/userproperty/Messages_pl.properties

@@ -0,0 +1,32 @@
+# The MIT License
+#
+# Copyright 2025 Damian Szczepanik
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+UserPropertyCategory.Account.DisplayName=Konto
+UserPropertyCategory.Preferences.DisplayName=Ustawienia
+UserPropertyCategory.Experimental.DisplayName=Eksperymenty
+UserPropertyCategory.Appearance.DisplayName=Wygląd
+UserPropertyCategory.Security.DisplayName=Bezpieczeństwo
+UserPropertyCategory.Invisible.DisplayName=Niewidoczny
+UserPropertyCategoryAccountAction.DisplayName=Konto
+UserPropertyCategoryAppearanceAction.DisplayName=Wygląd
+UserPropertyCategoryExperimentalAction.DisplayName=Eksperymenty
+UserPropertyCategoryPreferencesAction.DisplayName=Ustawienia
+UserPropertyCategorySecurityAction.DisplayName=Bezpieczeństwo

core/src/main/resources/hudson/model/userproperty/UserPropertyCategoryAccountAction/index.jelly

@@ -30,16 +30,14 @@ THE SOFTWARE.
     <l:layout permission="${app.ADMINISTER}" title="${%title}">
         <st:include page="sidepanel.jelly" it="${it.targetUser}" />
         <l:main-panel>
-            <f:form method="post" action="configSubmit" name="config" class="jenkins-form">
-                <h1>
-                    ${%title}
-                </h1>
+            <l:app-bar title="${%title}" />
 
+            <f:form method="post" action="configSubmit" name="config" class="jenkins-form">
                 <j:set var="thisAction" value="${it}" />
                 <j:set var="it" value="${thisAction.targetUser}" />
                 <j:set var="instance" value="${it}"/>
 
-                <f:section>
+                <f:section title="${%General}">
                     <f:entry title="${%Full name}" description="${%Full name.Description}">
                         <f:textbox field="fullName" />
                     </f:entry>

core/src/main/resources/hudson/model/userproperty/UserPropertyCategoryAppearanceAction/index.jelly

@@ -30,11 +30,9 @@ THE SOFTWARE.
     <l:layout permission="${app.ADMINISTER}" title="${%title}">
         <st:include page="sidepanel.jelly" it="${it.targetUser}" />
         <l:main-panel>
+            <l:app-bar title="${%title}" />
+
             <f:form method="post" action="configSubmit" name="config" class="jenkins-form">
-                <h1>
-                    ${%title}
-                </h1>
-    
                 <j:set var="instance" value="${it}"/>
                 <j:set var="descriptors" value="${it.myCategoryDescriptors}" />
                 <j:set var="instances" value="${it.targetUser.properties}" />

core/src/main/resources/hudson/model/userproperty/UserPropertyCategoryExperimentalAction/index.jelly

@@ -30,11 +30,9 @@ THE SOFTWARE.
     <l:layout permission="${app.ADMINISTER}" title="${%title}">
         <st:include page="sidepanel.jelly" it="${it.targetUser}" />
         <l:main-panel>
+            <l:app-bar title="${%title}" />
+
             <f:form method="post" action="configSubmit" name="config">
-                <h1>
-                    ${%title}
-                </h1>
-    
                 <j:set var="instance" value="${it}"/>
                 <j:set var="descriptors" value="${it.myCategoryDescriptors}" />
                 <j:set var="instances" value="${it.targetUser.properties}" />

core/src/main/resources/hudson/model/userproperty/UserPropertyCategoryPreferencesAction/index.jelly

@@ -30,11 +30,9 @@ THE SOFTWARE.
     <l:layout permission="${app.ADMINISTER}" title="${%title}">
         <st:include page="sidepanel.jelly" it="${it.targetUser}" />
         <l:main-panel>
-            <f:form method="post" action="configSubmit" name="config">
-                <h1>
-                    ${%title}
-                </h1>
+            <l:app-bar title="${%title}" />
 
+            <f:form method="post" action="configSubmit" name="config">
                 <j:set var="instance" value="${it}"/>
                 <j:set var="descriptors" value="${it.myCategoryDescriptors}" />
                 <j:set var="instances" value="${it.targetUser.properties}" />

core/src/main/resources/hudson/model/userproperty/UserPropertyCategorySecurityAction/index.jelly

@@ -30,11 +30,9 @@ THE SOFTWARE.
     <l:layout permission="${app.ADMINISTER}" title="${%title}">
         <st:include page="sidepanel.jelly" it="${it.targetUser}" />
         <l:main-panel>
-            <f:form method="post" action="configSubmit" name="config">
-                <h1>
-                    ${%title}
-                </h1>
+            <l:app-bar title="${%title}" />
 
+            <f:form method="post" action="configSubmit" name="config">
                 <j:set var="instance" value="${it}"/>
                 <j:set var="descriptors" value="${it.myCategoryDescriptors}" />
                 <j:set var="instances" value="${it.targetUser.properties}" />

core/src/main/resources/hudson/widgets/HistoryWidget/index_pl.properties

@@ -1,6 +1,6 @@
 # The MIT License
 #
-# Copyright (c) 2004-2022, Kohsuke Kawaguchi, Sun Microsystems, Inc., and a number of other of contributors
+# Copyright (c) 2004-2025, Kohsuke Kawaguchi, Sun Microsystems, Inc., and a number of other of contributors
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -25,3 +25,4 @@ for\ failures=dla nieudanych
 Clear=wyczyść
 trend=trend
 find=szukaj
+No\ builds=Brak zadań

core/src/main/resources/jenkins/agents/Messages_pl.properties

@@ -1 +1,23 @@
-IOfflineCause.offline=rozłączony
+# The MIT License
+#
+# Copyright (c) 2025, Damian Szczepanik
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+CloudsLink.DisplayName=Chmura
+IOfflineCause.offline=Offline

core/src/main/resources/jenkins/install/Messages_pl.properties

@@ -0,0 +1,25 @@
+# The MIT License
+# 
+# Copyright 2025 Damian Szczepanik
+# 
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+# 
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+# 
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+SetupWizard_ConfigureInstance_ValidationErrors=Niektóre ustawienia są niepoprawne. Sprawdź komunikat błędu, aby zobaczyć szczegóły.
+SetupWizard_ConfigureInstance_RootUrl_Empty=Adres URL nie może być pusty
+SetupWizard_ConfigureInstance_RootUrl_Invalid=Adres URL jest niepoprawny, upewnij się, że używasz http:// lub https:// wraz z poprawnym adresem domeny.
+SetupWizard.DisplayName=Kreator konfiguracji

core/src/main/resources/jenkins/management/Messages.properties

@@ -66,5 +66,3 @@ ShutdownLink.Description=Stops executing new builds, so that the system can be e
 ShutdownLink.ShuttingDownInProgressDescription=Jenkins is currently shutting down. New builds are not executing.
 ShutdownLink.ShutDownReason_title=Reason
 ShutdownLink.ShutDownReason_update=Update reason
-
-AdministrativeMonitorsDecorator.DisplayName=Administrative Monitors Notifier

core/src/main/resources/jenkins/management/Messages_bg.properties

@@ -74,6 +74,3 @@ ShutdownLink.Description=\
 # Configure tools, their locations and automatic installers.
 ConfigureTools.Description=\
  Настройване на инструментите, местоположенията и автоматичното инсталиране.
-# Administrative Monitors Notifier
-AdministrativeMonitorsDecorator.DisplayName=\
- Известия за предупреждения

core/src/main/resources/jenkins/management/Messages_de.properties

@@ -49,5 +49,4 @@ NodesLink.Description=Knoten hinzufügen, entfernen, steuern und überwachen, au
 CliLink.Description=Jenkins aus der Kommandozeile oder skriptgesteuert nutzen und verwalten.
 CliLink.DisplayName=Jenkins CLI
 SystemLogLink.DisplayName=Systemlog
-AdministrativeMonitorsDecorator.DisplayName=Anzeige aktiver Administrator-Warnungen
 ConfigureTools.Description=Hilfsprogramme, ihre Installationsverzeichnisse und Installationsverfahren konfigurieren

core/src/main/resources/jenkins/management/Messages_it.properties

@@ -21,8 +21,6 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 
-AdministrativeMonitorsDecorator.DisplayName=Componente di notifica monitor \
-  amministrativi
 CliLink.Description=Accedi/gestisci Jenkins dal terminale o da uno script.
 CliLink.DisplayName=Interfaccia a riga di comando di Jenkins
 ConfigureLink.Description=Configura le impostazioni e i percorsi globali.

core/src/main/resources/jenkins/management/Messages_pt_BR.properties

@@ -45,7 +45,6 @@ NodesLink.Description=Adiciona, remove, controla e monitora o vários nós
 CliLink.DisplayName=Interface de Linha de Commando do Jenkins (CLI)
 ShutdownLink.DisplayName_update=Atualizar preparação de desligamento
 ShutdownLink.ShutDownReason_update=Atualizar razão
-AdministrativeMonitorsDecorator.DisplayName=Notificador de monitorações administrativas
 ConfigureTools.Description=Configurar ferramentas, suas localizações e instaladores automáticos.
 ShutdownLink.ShuttingDownInProgressDescription=O Jenkins está sendo desligado no momento. Novas construções não serão executadas.
 ShutdownLink.ShutDownReason_title=Razão

core/src/main/resources/jenkins/management/Messages_ru.properties

@@ -41,4 +41,3 @@ NodesLink.Description=Позволяет добавлять, удалять, к
 PluginsLink.Description=Добавить, удалить, отключить или включить плагины, расширяющие функционональные возможности Jenkins.
 ConfigureTools.Description=Конфигурация инструментов, их расположение и автоматическая инсталяция.
 SystemLogLink.DisplayName=Системный журнал
-AdministrativeMonitorsDecorator.DisplayName=Системные уведомления

core/src/main/resources/jenkins/management/Messages_sv_SE.properties

@@ -66,5 +66,3 @@ ShutdownLink.Description=Slutar köra nya byggen så att systemet eventuellt kan
 ShutdownLink.ShuttingDownInProgressDescription=Jenkins stängs ned för tillfället. Nya byggen körs inte.
 ShutdownLink.ShutDownReason_title=Anledning
 ShutdownLink.ShutDownReason_update=Uppdatera anledning
-
-AdministrativeMonitorsDecorator.DisplayName=Avisering om administrativ övervakning

core/src/main/resources/jenkins/management/Messages_zh_TW.properties

@@ -58,5 +58,3 @@ ShutdownLink.Description=不再執行新的建置作業，讓系統可以安全
 ShutdownLink.ShuttingDownInProgressDescription=Jenkins 正在停機，不會執行新的建置作業。
 ShutdownLink.ShutDownReason_title=原因
 ShutdownLink.ShutDownReason_update=更新原因
-
-AdministrativeMonitorsDecorator.DisplayName=管理監視器通知

core/src/main/resources/jenkins/model/Jenkins/_api.jelly

@@ -41,7 +41,7 @@ THE SOFTWARE.
 
   <h2>Restarting Jenkins</h2>
   <p>
-    Jenkins will enter into the "quiet down" mode by sending a POST request with optional <code>reason</code> query parameter to <a href="../quietDown">this URL</a>.
+    Jenkins will enter into the "quiet down" mode by sending a POST request with optional <code>message</code> query parameter as the reason to <a href="../quietDown">this URL</a>.
     You can also send another request to this URL to update the reason.
     You can cancel this mode by sending a POST request to <a href="../cancelQuietDown">this URL</a>. On environments
     where Jenkins can restart itself (such as when Jenkins is installed as a Windows service), POSTing to

core/src/main/resources/jenkins/model/Jenkins/login_pl.properties

@@ -1,6 +1,6 @@
 # The MIT License
 #
-# Copyright (c) 2013-2019, Sun Microsystems, Inc., Kohsuke Kawaguchi
+# Copyright (c) 2013-2025, Sun Microsystems, Inc., Kohsuke Kawaguchi
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -23,6 +23,7 @@
 Password=Hasło
 signUp=Zaloguj się poniżej lub <a href="signup">załóż konto</a>.
 signIn=Zaloguj
+Sign\ in\ to\ Jenkins=Zaloguj się do Jenkinsa
 Keep\ me\ signed\ in=Zapamiętaj mnie
 Username=Użytkownik
 Invalid\ username\ or\ password=Niepoprawny użytkownik lub hasło

core/src/main/resources/jenkins/model/experimentalflags/BooleanUserExperimentalFlag/flagConfig.jelly

@@ -24,12 +24,14 @@ THE SOFTWARE.
 
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:f="/lib/form">
-    <select class="jenkins-select__input" name="[${it.flagKey}]">
-        <f:option selected="${flagValue == null}" value="">
-            <j:if test="${it.getDefaultValue() == true}">${%Default_True}</j:if>
-            <j:if test="${it.getDefaultValue() == false}">${%Default_False}</j:if>
-        </f:option>
-        <f:option selected="${flagValue == true}" value="true">${%True}</f:option>
-        <f:option selected="${flagValue == false}" value="false">${%False}</f:option>
-    </select>
+    <div class="jenkins-select">
+        <select class="jenkins-select__input" name="[${it.flagKey}]">
+            <f:option selected="${flagValue == null}" value="">
+                <j:if test="${it.getDefaultValue() == true}">${%Default_True}</j:if>
+                <j:if test="${it.getDefaultValue() == false}">${%Default_False}</j:if>
+            </f:option>
+            <f:option selected="${flagValue == true}" value="true">${%True}</f:option>
+            <f:option selected="${flagValue == false}" value="false">${%False}</f:option>
+        </select>
+    </div>
 </j:jelly>

core/src/main/resources/jenkins/model/experimentalflags/UserExperimentalFlagsProperty/config.jelly

@@ -23,20 +23,20 @@ THE SOFTWARE.
 -->
 
 <?jelly escape-by-default='true'?>
-<j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:f="/lib/form">
+<j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:f="/lib/form" xmlns:l="/lib/layout">
     <j:set var="userProperty" value="${instance}"/>
-    <f:entry field="experimentalFlags">
-        <j:invokeStatic var="flagConfigs" className="jenkins.model.experimentalflags.UserExperimentalFlag"
-                        method="all"/>
-    
-        <j:if test="${empty(flagConfigs)}">
-            <div class="jenkins-form-item">
-                ${%NoFlagInfo}
-            </div>
-        </j:if>
-        <j:if test="${!empty(flagConfigs)}">
+    <j:invokeStatic var="flagConfigs" className="jenkins.model.experimentalflags.UserExperimentalFlag"
+                    method="all"/>
+
+    <j:if test="${empty(flagConfigs)}">
+        <l:notice icon="symbol-flask"
+                  title="${%NoFlagInfo}" />
+    </j:if>
+
+    <j:if test="${!empty(flagConfigs)}">
+        <f:entry field="experimentalFlags">
             <f:rowSet name="flags">
-                <table class="jenkins-table sortable">
+                <table class="jenkins-table sortable jenkins-!-margin-0">
                     <thead>
                         <tr>
                             <th>${%FlagDisplayName}</th>
@@ -62,6 +62,6 @@ THE SOFTWARE.
                     </tbody>
                 </table>
             </f:rowSet>
-        </j:if>
-    </f:entry>
+        </f:entry>
+    </j:if>
 </j:jelly>