Merge branch 'fix-mr-push-range' into 'master'

Fix condensed range in MR push comment.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/1246

In https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/326#note_984907, you see that the compare page doesn't actually have 39 commits because we're using `first_new_commit^`, which is not always the same as `oldrev`. With this MR, we use `oldrev` instead, which will always work.

See merge request !1721

app/models/note.rb

@@ -151,7 +151,7 @@ class Note < ActiveRecord::Base
       )
     end
 
-    def create_new_commits_note(merge_request, project, author, new_commits, existing_commits = [])
+    def create_new_commits_note(merge_request, project, author, new_commits, existing_commits = [], oldrev = nil)
       total_count = new_commits.length + existing_commits.length
       commits_text = ActionController::Base.helpers.pluralize(total_count, 'commit')
       body = "Added #{commits_text}:\n\n"
@@ -161,7 +161,11 @@ class Note < ActiveRecord::Base
           if existing_commits.length == 1
             existing_commits.first.short_id
           else
-            "#{existing_commits.first.short_id}..#{existing_commits.last.short_id}"
+            if oldrev
+              "#{Commit.truncate_sha(oldrev)}...#{existing_commits.last.short_id}"
+            else
+              "#{existing_commits.first.short_id}..#{existing_commits.last.short_id}"
+            end
           end
 
         commits_text = ActionController::Base.helpers.pluralize(existing_commits.length, 'commit')

app/services/merge_requests/refresh_service.rb

@@ -89,7 +89,7 @@ module MergeRequests
         end
 
         Note.create_new_commits_note(merge_request, merge_request.project,
-                                     @current_user, new_commits, existing_commits)
+                                     @current_user, new_commits, existing_commits, @oldrev)
       end
     end