Current directory (lodaer.path=.) pathology workaround

It turns out that loader.path=. was pathological and before this
change ended up making the classpath empty (loader.path=.,lib/
would have fixed it). With this change the old behaviour is still
supported, but if the only user-supplied path entry is "." (or
empty) then it is now kept, and translates into the root of the
current archive if running as "java -jar ...".

Fixes gh-270

spring-boot-cli/src/it/java/org/springframework/boot/cli/JarCommandIT.java

@@ -64,7 +64,7 @@ public class JarCommandIT {
 		Invocation invocation = this.cli.invoke("jar", jar.getAbsolutePath(),
 				"jar.groovy");
 		invocation.await();
-		assertEquals(0, invocation.getErrorOutput().length());
+		assertEquals(invocation.getErrorOutput(), 0, invocation.getErrorOutput().length());
 		assertTrue(jar.exists());
 
 		Process process = new JavaExecutable().processBuilder("-jar",

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/PropertiesLauncher.java

@@ -310,12 +310,18 @@ public class PropertiesLauncher extends Launcher {
 		List<String> paths = new ArrayList<String>();
 		for (String path : commaSeparatedPaths.split(",")) {
 			path = cleanupPath(path);
-			// Empty path is always on the classpath so no need for it to be explicitly
-			// listed here
+			// Empty path (i.e. the archive itself if running from a JAR) is always added
+			// to the classpath so no need for it to be explicitly listed
 			if (!(path.equals(".") || path.equals(""))) {
 				paths.add(path);
 			}
 		}
+		if (paths.isEmpty()) {
+			// On the other hand, we don't want a completely empty path. If the app is
+			// running from an archive (java -jar) then this will make sure the archive
+			// itself is included at the very least.
+			paths.add(".");
+		}
 		return paths;
 	}
 
@@ -453,12 +459,12 @@ public class PropertiesLauncher extends Launcher {
 		}
 		if (file.isDirectory()) {
 			this.logger.info("Adding classpath entries from " + file);
-			Archive archive = new ExplodedArchive(file);
+			Archive archive = new ExplodedArchive(file, false);
 			lib.add(archive);
 		}
 		Archive archive = getArchive(file);
 		if (archive != null) {
-			this.logger.info("Adding classpath entries from nested " + archive.getUrl()
+			this.logger.info("Adding classpath entries from archive " + archive.getUrl()
 					+ root);
 			lib.add(archive);
 		}

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/archive/ExplodedArchive.java

@@ -85,9 +85,9 @@ public class ExplodedArchive extends Archive {
 			this.entries.put(entry.getName(), entry);
 		}
 		if (file.isDirectory()) {
-			if (this.recursive) {
-				for (File child : file.listFiles()) {
-					if (!SKIPPED_NAMES.contains(child.getName())) {
+			for (File child : file.listFiles()) {
+				if (!SKIPPED_NAMES.contains(child.getName())) {
+					if (file.equals(this.root) || this.recursive) {
 						buildEntries(child);
 					}
 				}

spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/PropertiesLauncherTests.java

@@ -83,7 +83,14 @@ public class PropertiesLauncherTests {
 	}
 
 	@Test
-	public void testUserSpecifiedPath() throws Exception {
+	public void testUserSpecifiedDotPath() throws Exception {
+		System.setProperty("loader.path", ".");
+		PropertiesLauncher launcher = new PropertiesLauncher();
+		assertEquals("[.]", ReflectionTestUtils.getField(launcher, "paths").toString());
+	}
+
+	@Test
+	public void testUserSpecifiedWildcardPath() throws Exception {
 		System.setProperty("loader.path", "jars/*");
 		System.setProperty("loader.main", "demo.Application");
 		PropertiesLauncher launcher = new PropertiesLauncher();