Fix merge request comments on files with multiple commits

Having a merge request with a comments on a line which is then changed
in a later commit prevented new comments from properly showing up in the
merge request show page.

 * `Note#set_diff` do not use stored the diff when creating a new note
   in merge requests (we can not be sure the diff did not changed since
   the last comment on that line)
 * Do not rely just on `outdated?` of the first note when displaying
   comments of a MR in the discussion tab, but partition the
   active/outdated notes and display them all
 * In the inline changes tab just select the active notes, so an
   outdated note does not prevent an active one from being rendered
 * Just show active comments in the side-by-side changes tab

1 files changed, 1 insertions, 1 deletions

diff --git a/app/helpers/diff_helper.rb b/app/helpers/diff_helper.rb
index b56f21c7a18..4f42972a4dd 100644
--- a/app/helpers/diff_helper.rb
+++ b/app/helpers/diff_helper.rb
@@ -101,7 +101,7 @@ module DiffHelper
   end
 
   def line_comments
-    @line_comments ||= @line_notes.group_by(&:line_code)
+    @line_comments ||= @line_notes.select(&:active?).group_by(&:line_code)
   end
 
   def organize_comments(type_left, type_right, line_code_left, line_code_right)