1 files changed, 17 insertions, 6 deletions
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index d0811a715bc..861211ffc0a 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -539,15 +539,26 @@ class MergeRequest < ActiveRecord::Base
 
   def validate_branches
     if target_project == source_project && target_branch == source_branch
-      errors.add :branch_conflict, "You can not use same project/branch for source and target"
+      errors.add :branch_conflict, "You can't use same project/branch for source and target"
+      return
     end
 
     if opened?
-      similar_mrs = self.target_project.merge_requests.where(source_branch: source_branch, target_branch: target_branch, source_project_id: source_project.try(:id)).opened
-      similar_mrs = similar_mrs.where('id not in (?)', self.id) if self.id
-      if similar_mrs.any?
-        errors.add :validate_branches,
-                   "Cannot Create: This merge request already exists: #{similar_mrs.pluck(:title)}"
+      similar_mrs = target_project
+        .merge_requests
+        .where(source_branch: source_branch, target_branch: target_branch)
+        .where(source_project_id: source_project&.id)
+        .opened
+
+      similar_mrs = similar_mrs.where.not(id: id) if persisted?
+
+      conflict = similar_mrs.first
+
+      if conflict.present?
+        errors.add(
+          :validate_branches,
+          "Another open merge request already exists for this source branch: #{conflict.to_reference}"
+        )
       end
     end
   end