CE upstream

CE changes https://gitlab.com/gitlab-org/gitlab-ce/compare/d636efbe26ee51030bb108d889c2ef867570358a...0c36b810abede73b3cf59f951e7467dbac54ec98?expand_all_diffs=1

app/models/concerns/issuable.rb

@@ -286,6 +286,11 @@ def can_move?(*)
     false
   end
+  def assignee_or_author?(user)
+    # We're comparing IDs here so we don't need to load any associations.
+    author_id == user.id || assignee_id == user.id
+  end
+
   def record_metrics
     metrics = self.metrics || create_metrics
     metrics.record!