Automatic merge of gitlab-org/gitlab-ce master

app/assets/javascripts/notes/stores/actions.js

@@ -415,12 +415,13 @@ export const submitSuggestion = (
       commit(types.APPLY_SUGGESTION, { discussionId, noteId, suggestionId });
       callback();
     })
-    .catch(() => {
-      Flash(
-        __('Something went wrong while applying the suggestion. Please try again.'),
-        'alert',
-        flashContainer,
+    .catch(err => {
+      const defaultMessage = __(
+        'Something went wrong while applying the suggestion. Please try again.',
       );
+      const flashMessage = err.response.data ? `${err.response.data.message}.` : defaultMessage;
+
+      Flash(__(flashMessage), 'alert', flashContainer);
       callback();
     });
 };

app/services/suggestions/apply_service.rb

@@ -11,7 +11,7 @@ module Suggestions
         return error('Suggestion is not appliable')
       end
 
-      unless latest_diff_refs?(suggestion)
+      unless latest_source_head?(suggestion)
         return error('The file has been changed')
       end
 
@@ -29,12 +29,13 @@ module Suggestions
 
     private
 
-    # Checks whether the latest diff refs for the branch matches with
-    # the position refs we're using to update the file content. Since
-    # the persisted refs are updated async (for MergeRequest),
-    # it's more consistent to fetch this data directly from the repository.
-    def latest_diff_refs?(suggestion)
-      suggestion.position.diff_refs == suggestion.noteable.repository_diff_refs
+    # Checks whether the latest source branch HEAD matches with
+    # the position HEAD we're using to update the file content. Since
+    # the persisted HEAD is updated async (for MergeRequest),
+    # it's more consistent to fetch this data directly from the
+    # repository.
+    def latest_source_head?(suggestion)
+      suggestion.position.head_sha == suggestion.noteable.source_branch_sha
     end
 
     def file_update_params(suggestion)

changelogs/unreleased/osw-adjusts-suggestions-unable-to-be-applied.yml

+---
+title: Adjusts suggestions unable to be applied
+merge_request: 24603
+author:
+type: fixed

spec/services/suggestions/apply_service_spec.rb

@@ -134,12 +134,11 @@ describe Suggestions::ApplyService do
         end
       end
 
-      context 'when diff ref from position is different from repo diff refs' do
+      context 'when HEAD from position is different from source branch HEAD on repo' do
         it 'returns error message' do
-          outdated_refs = Gitlab::Diff::DiffRefs.new(base_sha: 'foo', start_sha: 'bar', head_sha: 'outdated')
-
           allow(suggestion).to receive(:appliable?) { true }
-          allow(suggestion.position).to receive(:diff_refs) { outdated_refs }
+          allow(suggestion.position).to receive(:head_sha) { 'old-sha' }
+          allow(suggestion.noteable).to receive(:source_branch_sha) { 'new-sha' }
 
           result = subject.execute(suggestion)