Add latest changes from gitlab-org/gitlab@master

3 files changed, 30 insertions, 10 deletions

diff --git a/app/services/merge_requests/merge_service.rb b/app/services/merge_requests/merge_service.rb
index 31097b9151a..3405ea389f8 100644
--- a/app/services/merge_requests/merge_service.rb
+++ b/app/services/merge_requests/merge_service.rb
@@ -27,6 +27,7 @@ module MergeRequests
           success
         end
       end
+
       log_info("Merge process finished on JID #{merge_jid} with state #{state}")
     rescue MergeError => e
       handle_merge_error(log_message: e.message, save_message_on_model: true)
@@ -54,7 +55,7 @@ module MergeRequests
       error =
         if @merge_request.should_be_rebased?
           'Only fast-forward merge is allowed for your project. Please update your source branch'
-        elsif !@merge_request.mergeable?
+        elsif !@merge_request.merged? && !@merge_request.mergeable?
           'Merge request is not mergeable'
         end
 
diff --git a/app/services/merge_requests/post_merge_service.rb b/app/services/merge_requests/post_merge_service.rb
index 0364c0dd479..a3d7f623546 100644
--- a/app/services/merge_requests/post_merge_service.rb
+++ b/app/services/merge_requests/post_merge_service.rb
@@ -8,17 +8,28 @@ module MergeRequests
   #
   class PostMergeService < MergeRequests::BaseService
     def execute(merge_request)
-      merge_request.mark_as_merged
-      close_issues(merge_request)
-      todo_service.merge_merge_request(merge_request, current_user)
-      create_event(merge_request)
-      create_note(merge_request)
+      # These operations need to happen transactionally
+      ActiveRecord::Base.transaction(requires_new: true) do
+        merge_request.mark_as_merged
+
+        # These options do not call external services and should be
+        # relatively quick enough to put in a Transaction
+        create_event(merge_request)
+        todo_service.merge_merge_request(merge_request, current_user)
+      end
+
+      # These operations are idempotent so can be safely run multiple times
       notification_service.merge_mr(merge_request, current_user)
-      execute_hooks(merge_request, 'merge')
+      create_note(merge_request)
+      close_issues(merge_request)
       invalidate_cache_counts(merge_request, users: merge_request.assignees)
       merge_request.update_project_counter_caches
       delete_non_latest_diffs(merge_request)
       cleanup_environments(merge_request)
+
+      # Anything after this point will be executed at-most-once. Less important activity only
+      # TODO: make all the work in here a separate sidekiq job so it can go in the transaction
+      execute_hooks(merge_request, 'merge')
     end
 
     private
diff --git a/app/services/merge_requests/squash_service.rb b/app/services/merge_requests/squash_service.rb
index d25997c925e..09d867f39ae 100644
--- a/app/services/merge_requests/squash_service.rb
+++ b/app/services/merge_requests/squash_service.rb
@@ -4,12 +4,14 @@ module MergeRequests
   class SquashService < MergeRequests::BaseService
     include Git::Logger
 
+    def idempotent?
+      true
+    end
+
     def execute
       # If performing a squash would result in no change, then
       # immediately return a success message without performing a squash
-      if merge_request.commits_count < 2 && message.nil?
-        return success(squash_sha: merge_request.diff_head_sha)
-      end
+      return success(squash_sha: merge_request.diff_head_sha) if squash_redundant?
 
       if merge_request.squash_in_progress?
         return error(s_('MergeRequests|Squash task canceled: another squash is already in progress.'))
@@ -20,6 +22,12 @@ module MergeRequests
 
     private
 
+    def squash_redundant?
+      return true if merge_request.merged?
+
+      merge_request.commits_count < 2 && message.nil?
+    end
+
     def squash!
       squash_sha = repository.squash(current_user, merge_request, message || merge_request.default_squash_commit_message)