Allow user to specify default remote when there's no remote named "origin"

src/GitHub.App/SampleData/GitServiceDesigner.cs

@@ -8,9 +8,10 @@ namespace GitHub.SampleData
     class GitServiceDesigner : IGitService
     {
         public Task<string> GetLatestPushedSha(string path) => Task.FromResult<string>(null);
-        public UriString GetRemoteUri(IRepository repo, string remote = "origin") => null;
+        public UriString GetRemoteUri(IRepository repo, string remote = null) => null;
         public IRepository GetRepository(string path) => null;
-        public UriString GetUri(string path, string remote = "origin") => null;
-        public UriString GetUri(IRepository repository, string remote = "origin") => null;
+        public UriString GetUri(string path, string remote = null) => null;
+        public UriString GetUri(IRepository repository, string remote = null) => null;
+        public string GetDefaultRemoteName(IRepository repo) => null;
     }
 }

src/GitHub.App/Services/GitClient.cs

@@ -17,7 +17,6 @@ namespace GitHub.Services
     [PartCreationPolicy(CreationPolicy.Shared)]
     public class GitClient : IGitClient
     {
-        const string defaultOriginName = "origin";
         static readonly ILogger log = LogManager.ForContext<GitClient>();
         readonly IGitService gitService;
         readonly PullOptions pullOptions;
@@ -98,10 +97,11 @@ public Task Fetch(IRepository repo, UriString cloneUrl, params string[] refspecs
         {
             var httpsUrl = UriString.ToUriString(cloneUrl.ToRepositoryUrl());
 
-            var originRemote = repo.Network.Remotes[defaultOriginName];
+            var originName = gitService.GetDefaultRemoteName(repo);
+            var originRemote = repo.Network.Remotes[originName];
             if (originRemote != null && originRemote.Url == httpsUrl)
             {
-                return Fetch(repo, defaultOriginName, refspecs);
+                return Fetch(repo, originName, refspecs);
             }
 
             return Task.Factory.StartNew(() =>
@@ -335,13 +335,13 @@ public Task UnsetConfig(IRepository repository, string key)
             });
         }
 
-        public Task<Remote> GetHttpRemote(IRepository repo, string remote)
+        public Task<Remote> GetHttpRemote(IRepository repo, string remote = null)
         {
             Guard.ArgumentNotNull(repo, nameof(repo));
-            Guard.ArgumentNotEmptyString(remote, nameof(remote));
 
             return Task.Factory.StartNew(() =>
             {
+                remote = remote ?? gitService.GetDefaultRemoteName(repo);
                 var uri = gitService.GetRemoteUri(repo, remote);
                 var remoteName = uri.IsHypertextTransferProtocol ? remote : remote + "-http";
                 var ret = repo.Network.Remotes[remoteName];

src/GitHub.App/Services/PullRequestService.cs

@@ -287,7 +287,7 @@ public IObservable<Unit> Checkout(ILocalRepositoryModel repository, IPullRequest
                     }
                     else if (repository.CloneUrl.ToRepositoryUrl() == pullRequest.Head.RepositoryCloneUrl.ToRepositoryUrl())
                     {
-                        var remote = await gitClient.GetHttpRemote(repo, "origin");
+                        var remote = await gitClient.GetHttpRemote(repo);
                         await gitClient.Fetch(repo, remote.Name);
                         await gitClient.Checkout(repo, localBranchName);
                     }
@@ -371,7 +371,7 @@ public IObservable<TreeChanges> GetTreeChanges(ILocalRepositoryModel repository,
                 // TreeChanges doesn't keep a reference to Repository
                 using (var repo = gitService.GetRepository(repository.LocalPath))
                 {
-                    var remote = await gitClient.GetHttpRemote(repo, "origin");
+                    var remote = await gitClient.GetHttpRemote(repo);
                     await gitClient.Fetch(repo, remote.Name);
                     var changes = await gitClient.Compare(repo, pullRequest.Base.Sha, pullRequest.Head.Sha, detectRenames: true);
                     return Observable.Return(changes);
@@ -437,7 +437,7 @@ public IObservable<Unit> SwitchToBranch(ILocalRepositoryModel repository, IPullR
 
                     if (branchName != null)
                     {
-                        var remote = await gitClient.GetHttpRemote(repo, "origin");
+                        var remote = await gitClient.GetHttpRemote(repo);
                         await gitClient.Fetch(repo, remote.Name);
 
                         var branch = repo.Branches[branchName];
@@ -497,7 +497,7 @@ public async Task<string> ExtractToTempFile(
             {
                 using (var repo = gitService.GetRepository(repository.LocalPath))
                 {
-                    var remote = await gitClient.GetHttpRemote(repo, "origin");
+                    var remote = await gitClient.GetHttpRemote(repo);
                     await ExtractToTempFile(repo, pullRequest.Number, commitSha, relativePath, encoding, tempFilePath);
                 }
             }
@@ -610,7 +610,7 @@ async Task ExtractToTempFile(
             catch (FileNotFoundException)
             {
                 var pullHeadRef = $"refs/pull/{pullRequestNumber}/head";
-                var remote = await gitClient.GetHttpRemote(repo, "origin");
+                var remote = await gitClient.GetHttpRemote(repo);
                 await gitClient.Fetch(repo, remote.Name, commitSha, pullHeadRef);
                 contents = await gitClient.ExtractFile(repo, commitSha, relativePath) ?? string.Empty;
             }
@@ -663,7 +663,7 @@ async Task<IPullRequestModel> PushAndCreatePR(IModelService modelService,
             // PullRequestModel doesn't keep a reference to repo
             using (var repo = await Task.Run(() => gitService.GetRepository(sourceRepository.LocalPath)))
             {
-                var remote = await gitClient.GetHttpRemote(repo, "origin");
+                var remote = await gitClient.GetHttpRemote(repo);
                 await gitClient.Push(repo, sourceBranch.Name, remote.Name);
 
                 if (!repo.Branches[sourceBranch.Name].IsTracking)

src/GitHub.App/Services/RepositoryForkService.cs

@@ -76,7 +76,7 @@ public IObservable<object> SwitchRemotes(IRepositoryModel destinationRepository,
 
                         if (addUpstream)
                         {
-                            var remote = await gitClient.GetHttpRemote(activeRepo, "origin");
+                            var remote = await gitClient.GetHttpRemote(activeRepo);
                             currentOrigin = new Uri(remote.Url);
                         }
 

src/GitHub.Exports.Reactive/Services/IGitClient.cs

@@ -152,7 +152,13 @@ public interface IGitClient
         /// <returns></returns>
         Task UnsetConfig(IRepository repository, string key);
 
-        Task<Remote> GetHttpRemote(IRepository repo, string remote);
+        /// <summary>
+        /// Get a <see cref="Remote"/> that used the http protocol.
+        /// </summary>
+        /// <param name="repository">The repository</param>
+        /// <param name="remote">The name of the remote or null to use original remote.</param>
+        /// <returns>A <see cref="Remote"/> that uses the http protocol.</returns>
+        Task<Remote> GetHttpRemote(IRepository repo, string remote = null);
 
         /// <summary>
         /// Extracts a file at a specified commit from the repository.

src/GitHub.Exports/Services/GitService.cs

@@ -13,14 +13,16 @@ namespace GitHub.Services
     [PartCreationPolicy(CreationPolicy.NonShared)]
     public class GitService : IGitService
     {
+        const string defaultOriginName = "origin";
+
         /// <summary>
         /// Returns the URL of the remote for the specified <see cref="repository"/>. If the repository
         /// is null or no remote named origin exists, this method returns null
         /// </summary>
         /// <param name="repository">The repository to look at for the remote.</param>
         /// <param name="remote">The name of the remote to look for</param>
         /// <returns>Returns a <see cref="UriString"/> representing the uri of the remote normalized to a GitHub repository url or null if none found.</returns>
-        public UriString GetUri(IRepository repository, string remote = "origin")
+        public UriString GetUri(IRepository repository, string remote = null)
         {
             return UriString.ToUriString(GetRemoteUri(repository, remote)?.ToRepositoryUrl());
         }
@@ -36,7 +38,7 @@ public UriString GetUri(IRepository repository, string remote = "origin")
         /// <param name="path">The path to start probing</param>
         /// <param name="remote">The name of the remote to look for</param>
         /// <returns>Returns a <see cref="UriString"/> representing the uri of the remote normalized to a GitHub repository url or null if none found.</returns>
-        public UriString GetUri(string path, string remote = "origin")
+        public UriString GetUri(string path, string remote = null)
         {
             using (var repo = GetRepository(path))
             {
@@ -66,10 +68,21 @@ public IRepository GetRepository(string path)
         /// <param name="repo"></param>
         /// <param name="remote">The name of the remote to look for</param>
         /// <returns></returns>
-        public UriString GetRemoteUri(IRepository repo, string remote = "origin")
+        public UriString GetRemoteUri(IRepository repo, string remote = null)
         {
+            if (repo == null)
+            {
+                return null;
+            }
+
+            remote = remote ?? TryGetDefaultRemoteName(repo);
+            if (remote == null)
+            {
+                return null;
+            }
+
             return repo
-                ?.Network
+                .Network
                 .Remotes[remote]
                 ?.Url;
         }
@@ -117,5 +130,43 @@ public Task<string> GetLatestPushedSha(string path)
                 }
             });
         }
+
+        /// <summary>
+        /// Find a remote named "origin" or the remote tracking "master".
+        /// </summary>
+        /// <param name="repo">The <see cref="IRepository" /> to find a remote for.</param>
+        /// <returns>The remote named "origin" or the remote tracking "master"</returns>
+        /// <exception cref="InvalidOperationException">If repository contains no "origin" remote or "master" branch.</exception>
+        public string GetDefaultRemoteName(IRepository repo)
+        {
+            var remoteName = TryGetDefaultRemoteName(repo);
+            if (remoteName != null)
+            {
+                return remoteName;
+            }
+
+            throw new InvalidOperationException("Can't get default remote name because repository contains no `origin` remote or `master` branch.");
+        }
+
+        static string TryGetDefaultRemoteName(IRepository repo)
+        {
+            var remotes = repo.Network.Remotes;
+            var remote = remotes[defaultOriginName];
+            if (remote != null)
+            {
+                // Use remote named "origin"
+                return remote.Name;
+            }
+
+            var masterBranch = repo.Branches["master"];
+            var remoteName = masterBranch?.RemoteName;
+            if (remoteName != null)
+            {
+                // Use remote from the "master" branch
+                return remoteName;
+            }
+
+            return null;
+        }
     }
 }

src/GitHub.Exports/Services/IGitService.cs

@@ -13,7 +13,7 @@ public interface IGitService
         /// </summary>
         /// <param name="repository">The repository to look at for the remote.</param>
         /// <returns>A <see cref="UriString"/> representing the origin or null if none found.</returns>
-        UriString GetUri(IRepository repository, string remote = "origin");
+        UriString GetUri(IRepository repository, string remote = null);
 
         /// <summary>
         /// Probes for a git repository and if one is found, returns a <see cref="UriString"/> for the repository's
@@ -25,8 +25,8 @@ public interface IGitService
         /// </remarks>
         /// <param name="path">The path to start probing</param>
         /// <returns>A <see cref="UriString"/> representing the origin or null if none found.</returns>
-        UriString GetUri(string path, string remote = "origin");
-        
+        UriString GetUri(string path, string remote = null);
+
         /// <summary>
         /// Probes for a git repository and if one is found, returns a <see cref="IRepositoryModel"/> instance for the
         /// repository.
@@ -44,7 +44,7 @@ public interface IGitService
         /// </summary>
         /// <param name="repo"></param>
         /// <returns></returns>
-        UriString GetRemoteUri(IRepository repo, string remote = "origin");
+        UriString GetRemoteUri(IRepository repo, string remote = null);
 
         /// <summary>
         /// Finds the latest pushed commit of a file and returns the sha of that commit. Returns null when no commits have 
@@ -53,5 +53,13 @@ public interface IGitService
         /// <param name="path">The local path of a repository or a file inside a repository. This cannot be null.</param>
         /// <returns></returns>
         Task<string> GetLatestPushedSha(string path);
+
+        /// <summary>
+        /// Find a remote named "origin" or the remote tracking "master".
+        /// </summary>
+        /// <param name="repo">The <see cref="IRepository" /> to find a remote for.</param>
+        /// <returns>The remote named "origin" or the remote tracking "master"</returns>
+        /// <exception cref="InvalidOperationException">If repository contains no "origin" remote or "master" branch.</exception>
+        string GetDefaultRemoteName(IRepository repo);
     }
 }

test/UnitTests/GitHub.App/Services/GitClientTests.cs

@@ -329,8 +329,10 @@ static IRepository MockRepo(string baseSha, string headSha, string mergeBaseSha)
 
     static GitClient CreateGitClient()
     {
+        var gitService = Substitute.For<IGitService>();
+        gitService.GetDefaultRemoteName(null).ReturnsForAnyArgs("origin");
         return new GitClient(
             Substitute.For<IGitHubCredentialProvider>(),
-            Substitute.For<IGitService>());
+            gitService);
     }
 }

test/UnitTests/GitHub.App/ViewModels/Dialog/PullRequestCreationViewModelTests.cs

@@ -36,6 +36,7 @@ static LibGit2Sharp.IRepository SetupLocalRepoMock(IGitClient gitClient, IGitSer
         l2repo.Branches.Returns(l2branchcol);
         l2repo.Head.Returns(l2branch);
         gitService.GetRepository(Args.String).Returns(l2repo);
+        gitService.GetDefaultRemoteName(l2repo).Returns(remote);
         return l2repo;
     }