Program: 7684
Project: 7684
Buggy source:
@Override public IProject[] addToWorkspace(final String[] referenceStrings,final ProjectSetSerializationContext context,final IProgressMonitor monitor) throws TeamException {
  final Map<URIish,Map<String,Set<ProjectReference>>> repositories=new LinkedHashMap<URIish,Map<String,Set<ProjectReference>>>();
  for (  final String reference : referenceStrings) {
    try {
      final ProjectReference projectReference=new ProjectReference(reference);
      Map<String,Set<ProjectReference>> repositoryBranches=repositories.get(projectReference.repository);
      if (repositoryBranches == null) {
        repositoryBranches=new HashMap<String,Set<ProjectReference>>();
        repositories.put(projectReference.repository,repositoryBranches);
      }
      Set<ProjectReference> projectReferences=repositoryBranches.get(projectReference.branch);
      if (projectReferences == null) {
        projectReferences=new TreeSet<ProjectReference>(new ProjectReferenceComparator());
        repositoryBranches.put(projectReference.branch,projectReferences);
      }
      projectReferences.add(projectReference);
    }
 catch (    final IllegalArgumentException e) {
      throw new TeamException(reference,e);
    }
catch (    final URISyntaxException e) {
      throw new TeamException(reference,e);
    }
  }
  final ArrayList<IProject> importedProjects=new ArrayList<IProject>();
  for (  final URIish gitUrl : repositories.keySet()) {
    Map<String,Set<ProjectReference>> branches=repositories.get(gitUrl);
    for (    final String branch : branches.keySet()) {
      final Set<ProjectReference> projects=branches.get(branch);
      try {
        final IPath workDir=getWorkingDir(gitUrl,branch,branches.keySet());
        if (workDir.toFile().exists()) {
          final Collection<String> projectNames=new LinkedList<String>();
          for (          final ProjectReference projectReference : projects)           projectNames.add(projectReference.projectDir);
          throw new TeamException(NLS.bind(CoreText.GitProjectSetCapability_CloneToExistingDirectory,new Object[]{workDir,projectNames,gitUrl}));
        }
        int timeout=60;
        String refName=Constants.R_HEADS + branch;
        final CloneOperation cloneOperation=new CloneOperation(gitUrl,true,null,workDir.toFile(),refName,Constants.DEFAULT_REMOTE_NAME,timeout);
        cloneOperation.run(monitor);
        final File repositoryPath=workDir.append(Constants.DOT_GIT_EXT).toFile();
        Activator.getDefault().getRepositoryUtil().addConfiguredRepository(repositoryPath);
        final IWorkspace workspace=ResourcesPlugin.getWorkspace();
        final IWorkspaceRoot root=workspace.getRoot();
        for (        final ProjectReference projectToImport : projects) {
          final IPath projectDir=workDir.append(projectToImport.projectDir);
          final IProjectDescription projectDescription=workspace.loadProjectDescription(projectDir.append(IProjectDescription.DESCRIPTION_FILE_NAME));
          final IProject project=root.getProject(projectDescription.getName());
          project.create(projectDescription,monitor);
          importedProjects.add(project);
          project.open(monitor);
          final ConnectProviderOperation connectProviderOperation=new ConnectProviderOperation(project,repositoryPath);
          connectProviderOperation.execute(monitor);
        }
      }
 catch (      final InvocationTargetException e) {
        throw TeamException.asTeamException(e);
      }
catch (      final CoreException e) {
        throw TeamException.asTeamException(e);
      }
catch (      final InterruptedException e) {
        return new IProject[0];
      }
    }
  }
  final IProject[] result=importedProjects.toArray(new IProject[importedProjects.size()]);
  return result;
}

Fixed version (ground truth):
@Override public IProject[] addToWorkspace(final String[] referenceStrings,final ProjectSetSerializationContext context,final IProgressMonitor monitor) throws TeamException {
  final Map<URIish,Map<String,Set<ProjectReference>>> repositories=new LinkedHashMap<URIish,Map<String,Set<ProjectReference>>>();
  for (  final String reference : referenceStrings) {
    try {
      final ProjectReference projectReference=new ProjectReference(reference);
      Map<String,Set<ProjectReference>> repositoryBranches=repositories.get(projectReference.repository);
      if (repositoryBranches == null) {
        repositoryBranches=new HashMap<String,Set<ProjectReference>>();
        repositories.put(projectReference.repository,repositoryBranches);
      }
      Set<ProjectReference> projectReferences=repositoryBranches.get(projectReference.branch);
      if (projectReferences == null) {
        projectReferences=new TreeSet<ProjectReference>(new ProjectReferenceComparator());
        repositoryBranches.put(projectReference.branch,projectReferences);
      }
      projectReferences.add(projectReference);
    }
 catch (    final IllegalArgumentException e) {
      throw new TeamException(reference,e);
    }
catch (    final URISyntaxException e) {
      throw new TeamException(reference,e);
    }
  }
  final ArrayList<IProject> importedProjects=new ArrayList<IProject>();
  for (  final Map.Entry<URIish,Map<String,Set<ProjectReference>>> entry : repositories.entrySet()) {
    final URIish gitUrl=entry.getKey();
    final Map<String,Set<ProjectReference>> branches=entry.getValue();
    for (    final Map.Entry<String,Set<ProjectReference>> branchEntry : branches.entrySet()) {
      final String branch=branchEntry.getKey();
      final Set<ProjectReference> projects=branchEntry.getValue();
      try {
        final IPath workDir=getWorkingDir(gitUrl,branch,branches.keySet());
        if (workDir.toFile().exists()) {
          final Collection<String> projectNames=new LinkedList<String>();
          for (          final ProjectReference projectReference : projects)           projectNames.add(projectReference.projectDir);
          throw new TeamException(NLS.bind(CoreText.GitProjectSetCapability_CloneToExistingDirectory,new Object[]{workDir,projectNames,gitUrl}));
        }
        int timeout=60;
        String refName=Constants.R_HEADS + branch;
        final CloneOperation cloneOperation=new CloneOperation(gitUrl,true,null,workDir.toFile(),refName,Constants.DEFAULT_REMOTE_NAME,timeout);
        cloneOperation.run(monitor);
        final File repositoryPath=workDir.append(Constants.DOT_GIT_EXT).toFile();
        Activator.getDefault().getRepositoryUtil().addConfiguredRepository(repositoryPath);
        final IWorkspace workspace=ResourcesPlugin.getWorkspace();
        final IWorkspaceRoot root=workspace.getRoot();
        for (        final ProjectReference projectToImport : projects) {
          final IPath projectDir=workDir.append(projectToImport.projectDir);
          final IProjectDescription projectDescription=workspace.loadProjectDescription(projectDir.append(IProjectDescription.DESCRIPTION_FILE_NAME));
          final IProject project=root.getProject(projectDescription.getName());
          project.create(projectDescription,monitor);
          importedProjects.add(project);
          project.open(monitor);
          final ConnectProviderOperation connectProviderOperation=new ConnectProviderOperation(project,repositoryPath);
          connectProviderOperation.execute(monitor);
        }
      }
 catch (      final InvocationTargetException e) {
        throw TeamException.asTeamException(e);
      }
catch (      final CoreException e) {
        throw TeamException.asTeamException(e);
      }
catch (      final InterruptedException e) {
        return new IProject[0];
      }
    }
  }
  final IProject[] result=importedProjects.toArray(new IProject[importedProjects.size()]);
  return result;
}