1 files changed, 24 insertions, 11 deletions
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 8d9a30397a9..0ba00d447e8 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -524,6 +524,14 @@ class MergeRequest < ActiveRecord::Base
     true
   end
 
+  def ff_merge_possible?
+    project.repository.ancestor?(target_branch_sha, diff_head_sha)
+  end
+
+  def should_be_rebased?
+    project.ff_merge_must_be_possible? && !ff_merge_possible?
+  end
+
   def can_cancel_merge_when_pipeline_succeeds?(current_user)
     can_be_merged_by?(current_user) || self.author == current_user
   end
@@ -552,14 +560,20 @@ class MergeRequest < ActiveRecord::Base
     commits_for_notes_limit = 100
     commit_ids = commit_shas.take(commits_for_notes_limit)
 
-    Note.where(
-      "(project_id = :target_project_id AND noteable_type = 'MergeRequest' AND noteable_id = :mr_id) OR" +
-      "((project_id = :source_project_id OR project_id = :target_project_id) AND noteable_type = 'Commit' AND commit_id IN (:commit_ids))",
-      mr_id: id,
-      commit_ids: commit_ids,
-      target_project_id: target_project_id,
-      source_project_id: source_project_id
-    )
+    commit_notes = Note
+      .except(:order)
+      .where(project_id: [source_project_id, target_project_id])
+      .where(noteable_type: 'Commit', commit_id: commit_ids)
+
+    # We're using a UNION ALL here since this results in better performance
+    # compared to using OR statements. We're using UNION ALL since the queries
+    # used won't produce any duplicates (e.g. a note for a commit can't also be
+    # a note for an MR).
+    union = Gitlab::SQL::Union
+      .new([notes, commit_notes], remove_duplicates: false)
+      .to_sql
+
+    Note.from("(#{union}) #{Note.table_name}")
   end
 
   alias_method :discussion_notes, :related_notes
@@ -734,10 +748,9 @@ class MergeRequest < ActiveRecord::Base
   end
 
   def has_ci?
-    has_ci_integration = source_project.try(:ci_service)
-    uses_gitlab_ci = all_pipelines.any?
+    return false if has_no_commits?
 
-    (has_ci_integration || uses_gitlab_ci) && commits.any?
+    !!(head_pipeline_id || all_pipelines.any? || source_project&.ci_service)
   end
 
   def branch_missing?