Show RightViewOnly when no changes in PR file diff

If LeftView and RightView text are identical, simply show RightViewOnly.

Author: jcansdale

src/GitHub.App/Services/PullRequestEditorService.cs

@@ -194,16 +194,23 @@ await pullRequestService.ExtractToTempFile(
 
                 diffViewer = GetDiffViewer(frame);
 
-                if (diffViewer.LeftView.TextBuffer.CurrentSnapshot.GetText() == string.Empty)
+                var leftText = diffViewer.LeftView.TextBuffer.CurrentSnapshot.GetText();
+                var rightText = diffViewer.RightView.TextBuffer.CurrentSnapshot.GetText();
+                if (leftText == string.Empty)
                 {
                     // Don't show LeftView when empty.
                     diffViewer.ViewMode = DifferenceViewMode.RightViewOnly;
                 }
-                else if (diffViewer.RightView.TextBuffer.CurrentSnapshot.GetText() == string.Empty)
+                else if (rightText == string.Empty)
                 {
                     // Don't show RightView when empty.
                     diffViewer.ViewMode = DifferenceViewMode.LeftViewOnly;
                 }
+                else if (leftText == rightText)
+                {
+                    // Don't show LeftView when no changes.
+                    diffViewer.ViewMode = DifferenceViewMode.RightViewOnly;
+                }
 
                 AddBufferTag(diffViewer.LeftView.TextBuffer, session, leftPath, mergeBase, DiffSide.Left);
 

src/GitHub.VisualStudio/Commands/OpenFileInSolutionCommand.cs

@@ -108,12 +108,6 @@ public override async Task Execute()
                 // TODO: add metrics
                 // await usageTracker.Value.IncrementCounter(x => x.NumberOf???);
 
-                var sessionFile = await session.GetFile(relativePath);
-                if (sessionFile.Diff.Count == 0)
-                {
-                    statusBar.Value.ShowMessage("No changes in PR file: " + relativePath);
-                    return;
-                }
 
                 var diffViewer = await pullRequestEditorService.Value.OpenDiff(session, relativePath, "HEAD", scrollToFirstDiff: false);
                 if (diffViewer == null)