Merge pull request #1123 from github/fixes/1044-pending-review-comments

Add message for pending review comments.

Author: jcansdale

src/GitHub.InlineReviews/ViewModels/CommentViewModel.cs

@@ -7,6 +7,7 @@
 using GitHub.Extensions;
 using GitHub.Models;
 using GitHub.UI;
+using Octokit;
 using ReactiveUI;
 
 namespace GitHub.InlineReviews.ViewModels
@@ -154,7 +155,18 @@ async Task DoCommitEdit(object unused)
             }
             catch (Exception e)
             {
-                ErrorMessage = e.Message;
+                var message = e.Message;
+
+                if (e is ApiValidationException)
+                {
+                    // HACK: If the user has pending review comments on the server then we can't
+                    // post new comments. The correct way to test for this would be to make a
+                    // request to /repos/:owner/:repo/pulls/:number/reviews and check for comments
+                    // with a PENDING state. For the moment however we'll just display a message.
+                    message += ". Do you have pending review comments?";
+                }
+
+                ErrorMessage = message;
             }
         }