Clone: surface the real clone failure instead of a misleading InvalidDataException

GVFS/GVFS.FunctionalTests/Tests/EnlistmentPerFixture/CloneTests.cs

@@ -73,6 +73,31 @@ public void CloneCreatesCorrectFilesInRoot()
             }
         }
 
+        [TestCase]
+        public void CloneWithNonExistentBranchFailsWithBranchError()
+        {
+            string newEnlistmentRoot = GVFSFunctionalTestEnlistment.GetUniqueEnlistmentRoot();
+
+            ProcessStartInfo processInfo = new ProcessStartInfo(GVFSTestConfig.PathToGVFS);
+            processInfo.Arguments = $"clone {GVFSTestConfig.RepoToClone} {newEnlistmentRoot} --branch nonexistent/branch/that/does/not/exist";
+            processInfo.WindowStyle = ProcessWindowStyle.Hidden;
+            processInfo.CreateNoWindow = true;
+            processInfo.WorkingDirectory = Path.GetDirectoryName(this.Enlistment.EnlistmentRoot);
+            processInfo.UseShellExecute = false;
+            processInfo.RedirectStandardOutput = true;
+
+            ProcessResult result = ProcessHelper.Run(processInfo);
+            result.ExitCode.ShouldEqual(GVFSGenericError);
+
+            // The clone should surface the real, actionable failure...
+            result.Output.ShouldContain("Remote branch nonexistent/branch/that/does/not/exist not found in upstream origin");
+
+            // ...and NOT the misleading downstream exception that used to be thrown when
+            // a LibGit2RepoInvoker was constructed against a src folder that was never created.
+            result.Output.ShouldNotContain(false, "Couldn't open repo");
+            result.Output.ShouldNotContain(false, "InvalidDataException");
+        }
+
         private void SubfolderCloneShouldFail()
         {
             ProcessStartInfo processInfo = new ProcessStartInfo(GVFSTestConfig.PathToGVFS);

GVFS/GVFS/CommandLine/CloneVerb.cs

@@ -152,7 +152,7 @@ public override void Execute()
 
                 CacheServerInfo cacheServer = null;
                 ServerGVFSConfig serverGVFSConfig = null;
-                bool trustPackIndexes;
+                bool trustPackIndexes = false;
 
                 using (JsonTracer tracer = new JsonTracer(GVFSConstants.GVFSEtwProviderName, "GVFSClone"))
                 {
@@ -248,10 +248,17 @@ public override void Execute()
                     {
                         tracer.RelatedError(cloneResult.ErrorMessage);
                     }
-
-                    using (var repo = new LibGit2RepoInvoker(tracer, enlistment.WorkingDirectoryBackingRoot))
+                    else
                     {
-                        trustPackIndexes = repo.GetConfigBoolOrDefault(GVFSConstants.GitConfig.TrustPackIndexes, GVFSConstants.GitConfig.TrustPackIndexesDefault);
+                        // Only inspect the freshly-cloned repo when the clone succeeded. On a failed
+                        // clone the 'src' working directory was never created, so constructing a
+                        // LibGit2RepoInvoker here would log a misleading "Couldn't open repo" warning
+                        // and throw an InvalidDataException that masks the real failure (e.g. the
+                        // "Remote branch ... not found in upstream origin" error surfaced below).
+                        using (var repo = new LibGit2RepoInvoker(tracer, enlistment.WorkingDirectoryBackingRoot))
+                        {
+                            trustPackIndexes = repo.GetConfigBoolOrDefault(GVFSConstants.GitConfig.TrustPackIndexes, GVFSConstants.GitConfig.TrustPackIndexesDefault);
+                        }
                     }
                 }