Get the Git SccService before IGitActionsExt

IGitActionsExt is proffered by SccProviderPackage, but isn't
advertised. To ensure that getting IGitActionsExt doesn't return null,
we first request the SccService which is advertised. This forces
SccProviderPackage to load and proffer IGitActionsExt.

Author: jcansdale

src/GitHub.TeamFoundation.14/Services/VSGitServices.cs

@@ -86,6 +86,18 @@ public async Task Clone(
             NavigateToHomePage(teamExplorer); // Show progress on Team Explorer - Home
             await WaitForCloneOnHomePageAsync(teamExplorer);
 #elif TEAMEXPLORER15 || TEAMEXPLORER16
+            // IGitActionsExt is proffered by SccProviderPackage, but isn't advertised.
+            // To ensure that getting IGitActionsExt doesn't return null, we first request the
+            // SccService which is advertised. This forces SccProviderPackage to load
+            // and proffer IGitActionsExt.
+            var gitSccServiceGuid = new Guid("28C35EB2-67EA-4C5F-B49D-DACF73A66989");
+            var gitSccServiceType = Type.GetTypeFromCLSID(gitSccServiceGuid);
+            var gitSccService = serviceProvider.GetService(gitSccServiceType);
+            if (gitSccService is null)
+            {
+                log.Warning("Couldn't find Git SccService with Guid {Guid}", gitSccServiceGuid);
+            }
+
             // The progress parameter uses the ServiceProgressData type which is defined in
             // Microsoft.VisualStudio.Shell.Framework. Referencing this assembly directly
             // would cause type conflicts, so we're using reflection to call CloneAsync.