Test status quo for @Primary + TransactionManagementConfigurer

This commit introduces tests for the status quo in production support
for multiple transaction managers registered as @Primary and via the
TransactionManagementConfigurer API.

See gh-24869

spring-tx/src/test/java/org/springframework/transaction/annotation/EnableTransactionManagementTests.java

@@ -31,6 +31,7 @@ import org.springframework.context.annotation.ConditionContext;
 import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.ConfigurationCondition;
+import org.springframework.context.annotation.Primary;
 import org.springframework.core.type.AnnotatedTypeMetadata;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.PlatformTransactionManager;
@@ -106,7 +107,6 @@ public class EnableTransactionManagementTests {
 		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(
 				EnableTxConfig.class, MultiTxManagerConfig.class);
 		TransactionalTestBean bean = ctx.getBean(TransactionalTestBean.class);
-
 		CallCountingTransactionManager txManager = ctx.getBean("txManager", CallCountingTransactionManager.class);
 		CallCountingTransactionManager txManager2 = ctx.getBean("txManager2", CallCountingTransactionManager.class);
 
@@ -122,6 +122,48 @@ public class EnableTransactionManagementTests {
 		ctx.close();
 	}
 
+	@Test
+	public void txManagerIsResolvedCorrectlyWhenMultipleManagersArePresentAndOneIsPrimary() {
+		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(
+				EnableTxConfig.class, PrimaryMultiTxManagerConfig.class);
+		TransactionalTestBean bean = ctx.getBean(TransactionalTestBean.class);
+		CallCountingTransactionManager primary = ctx.getBean("primary", CallCountingTransactionManager.class);
+		CallCountingTransactionManager txManager2 = ctx.getBean("txManager2", CallCountingTransactionManager.class);
+
+		// invoke a transactional method, causing the PlatformTransactionManager bean to be resolved.
+		bean.findAllFoos();
+
+		assertThat(primary.begun).isEqualTo(1);
+		assertThat(primary.commits).isEqualTo(1);
+		assertThat(primary.rollbacks).isEqualTo(0);
+		assertThat(txManager2.begun).isEqualTo(0);
+		assertThat(txManager2.commits).isEqualTo(0);
+		assertThat(txManager2.rollbacks).isEqualTo(0);
+
+		ctx.close();
+	}
+
+	@Test
+	public void txManagerIsResolvedCorrectlyWithTxMgmtConfigurerAndPrimaryPresent() {
+		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(
+				EnableTxConfig.class, PrimaryTxManagerAndTxMgmtConfigurerConfig.class);
+		TransactionalTestBean bean = ctx.getBean(TransactionalTestBean.class);
+		CallCountingTransactionManager primary = ctx.getBean("primary", CallCountingTransactionManager.class);
+		CallCountingTransactionManager annotationDriven = ctx.getBean("annotationDrivenTransactionManager", CallCountingTransactionManager.class);
+
+		// invoke a transactional method, causing the PlatformTransactionManager bean to be resolved.
+		bean.findAllFoos();
+
+		assertThat(primary.begun).isEqualTo(0);
+		assertThat(primary.commits).isEqualTo(0);
+		assertThat(primary.rollbacks).isEqualTo(0);
+		assertThat(annotationDriven.begun).isEqualTo(1);
+		assertThat(annotationDriven.commits).isEqualTo(1);
+		assertThat(annotationDriven.rollbacks).isEqualTo(0);
+
+		ctx.close();
+	}
+
 	/**
 	 * A cheap test just to prove that in ASPECTJ mode, the AnnotationTransactionAspect does indeed
 	 * get loaded -- or in this case, attempted to be loaded at which point the test fails.
@@ -295,6 +337,49 @@ public class EnableTransactionManagementTests {
 	}
 
 
+	@Configuration
+	static class PrimaryMultiTxManagerConfig {
+
+		@Bean
+		public TransactionalTestBean testBean() {
+			return new TransactionalTestBean();
+		}
+
+		@Bean
+		@Primary
+		public PlatformTransactionManager primary() {
+			return new CallCountingTransactionManager();
+		}
+
+		@Bean
+		public PlatformTransactionManager txManager2() {
+			return new CallCountingTransactionManager();
+		}
+	}
+
+
+	@Configuration
+	static class PrimaryTxManagerAndTxMgmtConfigurerConfig implements TransactionManagementConfigurer {
+
+		@Bean
+		public TransactionalTestBean testBean() {
+			return new TransactionalTestBean();
+		}
+
+		@Bean
+		@Primary
+		public PlatformTransactionManager primary() {
+			return new CallCountingTransactionManager();
+		}
+
+		@Bean
+		@Override
+		public PlatformTransactionManager annotationDrivenTransactionManager() {
+			return new CallCountingTransactionManager();
+		}
+	}
+
+
 	@Configuration
 	@EnableTransactionManagement
 	static class Spr11915Config {