Add workaround for out of date CurrentBranch issue

It appears VSGitExt.ActiveRepositoriesChanged is fired before the local
repository has actually changed its branch. This means we can't read
the branch information immediately!

Author: jcansdale

src/GitHub.App/ViewModels/GitHubPane/PullRequestDetailViewModel.cs

@@ -39,6 +39,7 @@ public sealed class PullRequestDetailViewModel : PanePageViewModelBase, IPullReq
         readonly ITeamExplorerContext teamExplorerContext;
         readonly ISyncSubmodulesCommand syncSubmodulesCommand;
         readonly IViewViewModelFactory viewViewModelFactory;
+        readonly IGitService gitService;
         IModelService modelService;
         PullRequestDetailModel model;
         IActorViewModel author;
@@ -77,7 +78,8 @@ public PullRequestDetailViewModel(
             ITeamExplorerContext teamExplorerContext,
             IPullRequestFilesViewModel files,
             ISyncSubmodulesCommand syncSubmodulesCommand,
-            IViewViewModelFactory viewViewModelFactory)
+            IViewViewModelFactory viewViewModelFactory,
+            IGitService gitService)
         {
             Guard.ArgumentNotNull(pullRequestsService, nameof(pullRequestsService));
             Guard.ArgumentNotNull(sessionManager, nameof(sessionManager));
@@ -86,6 +88,7 @@ public PullRequestDetailViewModel(
             Guard.ArgumentNotNull(teamExplorerContext, nameof(teamExplorerContext));
             Guard.ArgumentNotNull(syncSubmodulesCommand, nameof(syncSubmodulesCommand));
             Guard.ArgumentNotNull(viewViewModelFactory, nameof(viewViewModelFactory));
+            Guard.ArgumentNotNull(gitService, nameof(gitService));
 
             this.pullRequestsService = pullRequestsService;
             this.sessionManager = sessionManager;
@@ -94,6 +97,7 @@ public PullRequestDetailViewModel(
             this.teamExplorerContext = teamExplorerContext;
             this.syncSubmodulesCommand = syncSubmodulesCommand;
             this.viewViewModelFactory = viewViewModelFactory;
+            this.gitService = gitService;
             Files = files;
 
             Checkout = ReactiveCommand.CreateFromObservable(
@@ -401,6 +405,8 @@ public async Task Load(PullRequestDetailModel pullRequest)
 
                 var localBranches = await pullRequestsService.GetLocalBranches(LocalRepository, pullRequest).ToList();
 
+                // HACK: This is only necessary because the CurrentBranch is being read too early
+                gitService.Refresh(LocalRepository);
                 IsCheckedOut = localBranches.Contains(LocalRepository.CurrentBranch);
 
                 if (IsCheckedOut)

test/GitHub.App.UnitTests/ViewModels/GitHubPane/PullRequestDetailViewModelTests.cs

@@ -607,7 +607,8 @@ static Tuple<PullRequestDetailViewModel, IPullRequestService> CreateTargetAndSer
                 Substitute.For<ITeamExplorerContext>(),
                 Substitute.For<IPullRequestFilesViewModel>(),
                 Substitute.For<ISyncSubmodulesCommand>(),
-                Substitute.For<IViewViewModelFactory>());
+                Substitute.For<IViewViewModelFactory>(),
+                Substitute.For<IGitService>());
             vm.InitializeAsync(repository, Substitute.For<IConnection>(), "owner", "repo", 1).Wait();
 
             return Tuple.Create(vm, pullRequestService);