Program: 62678
Project: 62678
Buggy source:
@Test public void mergeRequest_build() throws IOException, InterruptedException, GitAPIException, ExecutionException {
  Git.init().setDirectory(tmp.getRoot()).call();
  tmp.newFile("String_Node_Str");
  Git git=Git.open(tmp.getRoot());
  git.add().addFilepattern("String_Node_Str");
  RevCommit commit=git.commit().setMessage("String_Node_Str").call();
  ObjectId head=git.getRepository().resolve(Constants.HEAD);
  String repositoryUrl=tmp.getRoot().toURI().toString();
  final OneShotEvent buildTriggered=new OneShotEvent();
  FreeStyleProject project=jenkins.createFreeStyleProject();
  project.setScm(new GitSCM(repositoryUrl));
  project.getBuildersList().add(new TestBuilder(){
    @Override public boolean perform(    AbstractBuild<?,?> build,    Launcher launcher,    BuildListener listener) throws InterruptedException, IOException {
      buildTriggered.signal();
      return true;
    }
  }
);
  project.setQuietPeriod(0);
  mergeRequestHookTriggerHandler.handle(project,mergeRequestHook().withObjectAttributes(mergeRequestObjectAttributes().withTargetBranch("String_Node_Str" + git.nameRev().add(head).call().get(head)).withState(State.opened).withIid(1).withTitle("String_Node_Str").withTargetProjectId(1).withSourceProjectId(1).withSourceBranch("String_Node_Str").withTargetBranch("String_Node_Str").withLastCommit(commit().withAuthor(user().withName("String_Node_Str").build()).withId(commit.getName()).build()).withSource(project().withName("String_Node_Str").withNamespace("String_Node_Str").withHomepage("String_Node_Str").withUrl("String_Node_Str").withSshUrl("String_Node_Str").withHttpUrl("String_Node_Str").build()).withTarget(project().withName("String_Node_Str").withNamespace("String_Node_Str").withHomepage("String_Node_Str").withUrl("String_Node_Str").withSshUrl("String_Node_Str").withHttpUrl("String_Node_Str").build()).build()).build(),true,BranchFilterFactory.newBranchFilter(branchFilterConfig().build(BranchFilterType.All)));
  buildTriggered.block(10000);
  assertThat(buildTriggered.isSignaled(),is(true));
}

Fixed version (ground truth):
@Test public void mergeRequest_build() throws IOException, InterruptedException, GitAPIException, ExecutionException {
  Git.init().setDirectory(tmp.getRoot()).call();
  tmp.newFile("String_Node_Str");
  Git git=Git.open(tmp.getRoot());
  git.add().addFilepattern("String_Node_Str");
  RevCommit commit=git.commit().setMessage("String_Node_Str").call();
  ObjectId head=git.getRepository().resolve(Constants.HEAD);
  String repositoryUrl=tmp.getRoot().toURI().toString();
  final OneShotEvent buildTriggered=new OneShotEvent();
  FreeStyleProject project=jenkins.createFreeStyleProject();
  project.setScm(new GitSCM(repositoryUrl));
  project.getBuildersList().add(new TestBuilder(){
    @Override public boolean perform(    AbstractBuild<?,?> build,    Launcher launcher,    BuildListener listener) throws InterruptedException, IOException {
      buildTriggered.signal();
      return true;
    }
  }
);
  project.setQuietPeriod(0);
  mergeRequestHookTriggerHandler.handle(project,mergeRequestHook().withObjectAttributes(mergeRequestObjectAttributes().withTargetBranch("String_Node_Str" + git.nameRev().add(head).call().get(head)).withState(State.opened).withIid(1).withTitle("String_Node_Str").withTargetProjectId(1).withSourceProjectId(1).withSourceBranch("String_Node_Str").withTargetBranch("String_Node_Str").withLastCommit(commit().withAuthor(user().withName("String_Node_Str").build()).withId(commit.getName()).build()).withSource(project().withName("String_Node_Str").withNamespace("String_Node_Str").withHomepage("String_Node_Str").withUrl("String_Node_Str").withSshUrl("String_Node_Str").withHttpUrl("String_Node_Str").build()).withTarget(project().withName("String_Node_Str").withNamespace("String_Node_Str").withHomepage("String_Node_Str").withUrl("String_Node_Str").withSshUrl("String_Node_Str").withHttpUrl("String_Node_Str").build()).build()).withProject(project().withWebUrl("String_Node_Str").build()).build(),true,BranchFilterFactory.newBranchFilter(branchFilterConfig().build(BranchFilterType.All)));
  buildTriggered.block(10000);
  assertThat(buildTriggered.isSignaled(),is(true));
}