Backend tweaks

app/controllers/projects/discussions_controller.rb

@@ -11,7 +11,7 @@ class Projects::DiscussionsController < Projects::ApplicationController
     render json: {
       resolved_by: discussion.resolved_by.try(:name),
-      updated_html: view_to_html_string('discussions/_headline', discussion: discussion)
+      discussion_headline_html: view_to_html_string('discussions/_headline', discussion: discussion)
     }
   end
@@ -21,7 +21,7 @@ class Projects::DiscussionsController < Projects::ApplicationController
     discussion.unresolve!
     render json: {
-      updated_html: view_to_html_string('discussions/_headline', discussion: discussion)
+      discussion_headline_html: view_to_html_string('discussions/_headline', discussion: discussion)
     }
   end

app/controllers/projects/notes_controller.rb

@@ -72,11 +72,11 @@ class Projects::NotesController < Projects::ApplicationController
     note.resolve!(current_user)
-    discussion = note.noteable.discussions.find { |d| d.id == note.discussion_id } || render_404
+    discussion = note.discussion
     render json: {
       resolved_by: note.resolved_by.try(:name),
-      updated_html: view_to_html_string('discussions/_headline', discussion: discussion)
+      discussion_headline_html: (view_to_html_string('discussions/_headline', discussion: discussion) if discussion)
     }
   end
@@ -85,10 +85,10 @@ class Projects::NotesController < Projects::ApplicationController
     note.unresolve!
-    discussion = note.noteable.discussions.find { |d| d.id == note.discussion_id } || render_404
+    discussion = note.discussion
     render json: {
-      updated_html: view_to_html_string('discussions/_headline', discussion: discussion)
+      discussion_headline_html: (view_to_html_string('discussions/_headline', discussion: discussion) if discussion)
     }
   end
@@ -164,7 +164,7 @@ class Projects::NotesController < Projects::ApplicationController
       }
       if note.diff_note?
-        discussion = Discussion.new([note])
+        discussion = note.as_discussion
         attrs.merge!(
           diff_discussion_html: diff_discussion_html(discussion),

app/models/diff_note.rb

@@ -76,7 +76,7 @@ class DiffNote < Note
   end
   def resolvable?
-    !system? && !for_commit?
+    !system? && for_merge_request?
   end
   def resolved?
@@ -103,10 +103,21 @@ class DiffNote < Note
     save!
   end
+  def discussion
+    return unless resolvable?
+
+    discussion_notes = self.noteable.notes.fresh.select { |n| n.discussion_id == self.discussion_id }
+    Discussion.new(discussion_notes)
+  end
+
+  def as_discussion
+    Discussion.new([self])
+  end
+
   private
   def supported?
-    !self.for_merge_request? || self.noteable.support_new_diff_notes?
+    for_commit? || self.noteable.support_new_diff_notes?
   end
   def set_original_position

app/views/discussions/_jump_to_next.html.haml

-- discussion = local_assigns.fetch(:discussion, false)
+- discussion = local_assigns.fetch(:discussion, nil)
 %jump-to-discussion{ "inline-template" => true, ":discussion-id" => "'#{discussion.try(:id)}'" }
   .btn-group{ role: "group",
     "v-show" => "!allResolved" }

app/views/discussions/_resolve_all.html.haml

-- if discussion.can_resolve?(current_user) && discussion.resolvable?
+- if discussion.can_resolve?(current_user)
   %resolve-all-btn{ ":namespace-path" => "'#{discussion.project.namespace.path}'",
       ":project-path" => "'#{discussion.project.path}'",
       ":discussion-id" => "'#{discussion.id}'",
-      ":merge-request-id" => "#{discussion.first_note.noteable.try(:iid)}",
+      ":merge-request-id" => "#{discussion.noteable.iid}",
       "inline-template" => true,
       "v-cloak" => true }
     %button.btn.btn-default{ type: "button", "@click" => "resolve", ":disabled" => "loading" }