Merge pull request #1250 from github/fixes/1249-temp-remote

Fix race condition when fetching from and deleting a temporary remote

Author: jcansdale

src/GitHub.App/Services/GitClient.cs

@@ -86,6 +86,41 @@ public Task Fetch(IRepository repository, string remoteName)
             });
         }
 
+        public Task Fetch(IRepository repo, UriString cloneUrl, params string[] refspecs)
+        {
+            var httpsUrl = UriString.ToUriString(cloneUrl.ToRepositoryUrl());
+
+            var originRemote = repo.Network.Remotes[defaultOriginName];
+            if (originRemote != null && originRemote.Url == httpsUrl)
+            {
+                return Fetch(repo, defaultOriginName, refspecs);
+            }
+
+            return Task.Factory.StartNew(() =>
+            {
+                try
+                {
+                    var tempRemoteName = cloneUrl.Owner + "-" + Guid.NewGuid();
+                    var remote = repo.Network.Remotes.Add(tempRemoteName, httpsUrl);
+                    try
+                    {
+                        repo.Network.Fetch(remote, refspecs, fetchOptions);
+                    }
+                    finally
+                    {
+                        repo.Network.Remotes.Remove(tempRemoteName);
+                    }
+                }
+                catch (Exception ex)
+                {
+                    log.Error("Failed to fetch", ex);
+#if DEBUG
+                    throw;
+#endif
+                }
+            });
+        }
+
         public Task Fetch(IRepository repository, string remoteName, params string[] refspecs)
         {
             Guard.ArgumentNotNull(repository, nameof(repository));
@@ -430,26 +465,6 @@ public Task<bool> IsHeadPushed(IRepository repo)
             });
         }
 
-        public Task Fetch(IRepository repo, UriString cloneUrl, params string[] refspecs)
-        {
-            var httpsUrl = UriString.ToUriString(cloneUrl.ToRepositoryUrl());
-            if (repo.Network.Remotes[defaultOriginName]?.Url == httpsUrl)
-            {
-                return Fetch(repo, defaultOriginName, refspecs);
-            }
-
-            var tempRemoteName = cloneUrl.Owner + "-" + Guid.NewGuid();
-            repo.Network.Remotes.Add(tempRemoteName, httpsUrl);
-            try
-            {
-                return Fetch(repo, tempRemoteName, refspecs);
-            }
-            finally
-            {
-                repo.Network.Remotes.Remove(tempRemoteName);
-            }
-        }
-
         static bool IsCanonical(string s)
         {
             Guard.ArgumentNotEmptyString(s, nameof(s));