[JENKINS-59793] A test showing how a build with faulty SubTasks doesn't stop

test/src/test/java/hudson/model/queue/BuildKeepsRunningWhenFaultySubTasksTest.java

+package hudson.model.queue;
+
+import hudson.model.AbstractProject;
+import hudson.model.Executor;
+import hudson.model.FreeStyleBuild;
+import hudson.model.FreeStyleProject;
+import hudson.model.Label;
+import hudson.model.Node;
+import hudson.model.Queue;
+import hudson.model.ResourceList;
+import org.junit.Rule;
+import org.junit.Test;
+import org.jvnet.hudson.test.Issue;
+import org.jvnet.hudson.test.JenkinsRule;
+import org.jvnet.hudson.test.LoggerRule;
+import org.jvnet.hudson.test.TestExtension;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+
+import static org.hamcrest.Matchers.notNullValue;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+
+public class BuildKeepsRunningWhenFaultySubTasksTest {
+    @Rule
+    public JenkinsRule j = new JenkinsRule();
+    
+    @Rule
+    public LoggerRule logs = new LoggerRule().record(Executor.class.getName(), Level.SEVERE).capture(100); //just in case future versions add more logs
+
+    public static final String ERROR_MESSAGE = "My unexpected exception";
+    
+    // When using SubTaskContributor (FailingSubTaskContributor) the build never ends
+    @Test
+    @Issue("JENKINS-59793")
+    public void buildDoesntFinishWhenSubTaskFails() throws Exception {
+        FreeStyleProject p = j.createProject(FreeStyleProject.class);
+        QueueTaskFuture<FreeStyleBuild> future = p.scheduleBuild2(0);
+        assertThat("Build should be actually scheduled by Jenkins", future, notNullValue());
+
+        // We get stalled waiting the finalization of the job
+        FreeStyleBuild build = future.get(5, TimeUnit.SECONDS);
+        assertTrue("The message is printed in the log", logs.getRecords().stream().anyMatch(r -> r.getThrown().getMessage().equals(ERROR_MESSAGE)));
+    }
+    
+    // A SubTask failing with an exception
+    @TestExtension
+    public static class FailingSubTaskContributor extends SubTaskContributor {
+        @Override
+        public Collection<? extends SubTask> forProject(final AbstractProject<?, ?> p) {
+            return Collections.singleton(new SubTask() {
+                private final SubTask outer = this;
+
+                public Queue.Executable createExecutable() throws IOException {
+                    return new Queue.Executable() {
+                        public SubTask getParent() {
+                            return outer;
+                        }
+
+                        public void run() {
+                            throw new ArrayIndexOutOfBoundsException(ERROR_MESSAGE);
+                        }
+
+                        public long getEstimatedDuration() {
+                            return 0;
+                        }
+                    };
+                }
+
+                @Override
+                public Label getAssignedLabel() {
+                    return null;
+                }
+                @Override
+                public Node getLastBuiltOn() {
+                    return null;
+                }
+                @Override
+                public long getEstimatedDuration() {
+                    return 0;
+                }
+                @Override
+                public Queue.Task getOwnerTask() {
+                    return p;
+                }
+                @Override
+                public Object getSameNodeConstraint() {
+                    return null;
+                }
+                @Override
+                public ResourceList getResourceList() {
+                    return ResourceList.EMPTY;
+                }
+                @Override
+                public String getDisplayName() {
+                    return "Subtask of " + p.getDisplayName();
+                }
+            });
+        }
+    }
+}