Auto resolve new notes of resolved discussions

**Why?**

The previous behavior had resolved discussions being unresolved
when commented on. This was strange UX, especially since there
is a separate button for "Comment & unresolve discussion".

https://gitlab.com/gitlab-org/gitlab-ce/issues/24128

**Note:**

- Also adds changelog

1 files changed, 14 insertions, 0 deletions

diff --git a/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb b/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb
index 8f595a2b095..8a16c011067 100644
--- a/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb
+++ b/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb
@@ -149,6 +149,20 @@ describe 'Merge request > User resolves diff notes and discussions', :js do
             end
           end
 
+          it 'allows user to comment' do
+            page.within '.diff-content' do
+              find('.js-note-text').set 'testing'
+
+              click_button 'Comment'
+
+              wait_for_requests
+            end
+
+            page.within '.line-resolve-all-container' do
+              expect(page).to have_content('1/1 discussion resolved')
+            end
+          end
+
           it 'allows user to unresolve from reply form without a comment' do
             page.within '.diff-content' do
               click_button 'Unresolve discussion'