Code Quality: Don't wait canceled git fetch (#17330)

Author: hishitetsu

src/Files.App/Utils/Git/GitHelpers.cs

@@ -333,7 +333,7 @@ public static bool ValidateBranchNameForRepository(string branchName, string rep
 				branch.FriendlyName.Equals(branchName, StringComparison.OrdinalIgnoreCase));
 		}
 
-		public static async void FetchOrigin(string? repositoryPath)
+		public static async void FetchOrigin(string? repositoryPath, CancellationToken cancellationToken = default)
 		{
 			if (string.IsNullOrWhiteSpace(repositoryPath))
 				return;
@@ -359,18 +359,24 @@ public static async void FetchOrigin(string? repositoryPath)
 
 			await DoGitOperationAsync<GitOperationResult>(() =>
 			{
+				cancellationToken.ThrowIfCancellationRequested();
+
 				var result = GitOperationResult.Success;
 				try
 				{
 					foreach (var remote in repository.Network.Remotes)
 					{
+						cancellationToken.ThrowIfCancellationRequested();
+
 						LibGit2Sharp.Commands.Fetch(
 							repository,
 							remote.Name,
 							remote.FetchRefSpecs.Select(rs => rs.Specification),
 							_fetchOptions,
 							"git fetch updated a ref");
 					}
+
+					cancellationToken.ThrowIfCancellationRequested();
 				}
 				catch (Exception ex)
 				{
@@ -384,6 +390,10 @@ await DoGitOperationAsync<GitOperationResult>(() =>
 
 			MainWindow.Instance.DispatcherQueue.TryEnqueue(() =>
 			{
+				if (cancellationToken.IsCancellationRequested)
+					// Do nothing because the operation was cancelled and another fetch may be in progress
+					return;
+
 				IsExecutingGitAction = false;
 				GitFetchCompleted?.Invoke(null, EventArgs.Empty);
 			});

src/Files.App/Views/Shells/BaseShellPage.cs

@@ -238,16 +238,17 @@ protected async void FilesystemViewModel_DirectoryInfoUpdated(object sender, Eve
 					? headBranch.Name
 					: string.Empty;
 
+				var isGitFetchCanceled = false;
 				if (!_gitFetch.IsCompleted)
 				{
 					_gitFetchToken.Cancel();
-					await _gitFetch;
-					_gitFetchToken.TryReset();
+					_gitFetchToken = new CancellationTokenSource();
+					isGitFetchCanceled = true;
 				}
-				if (InstanceViewModel.IsGitRepository && !GitHelpers.IsExecutingGitAction)
+				if (InstanceViewModel.IsGitRepository && (!GitHelpers.IsExecutingGitAction || isGitFetchCanceled))
 				{
 					_gitFetch = Task.Run(
-						() => GitHelpers.FetchOrigin(InstanceViewModel.GitRepositoryPath),
+						() => GitHelpers.FetchOrigin(InstanceViewModel.GitRepositoryPath, _gitFetchToken.Token),
 						_gitFetchToken.Token);
 				}
 			}