Use message body for merge request description

When a merge request is created from email, use message body
as merge request description. If message body is empty then
merge request description is still created from the source
branch commit (if there is only single commit in the merge
request).

If message body is empty and there are multiple commits in
the source branch, then merge request description is left empty.

Closes #40968

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/gitlab/email/handler/create_merge_request_handler.rb b/lib/gitlab/email/handler/create_merge_request_handler.rb
index c63666b98c1..e2f7c1d0257 100644
--- a/lib/gitlab/email/handler/create_merge_request_handler.rb
+++ b/lib/gitlab/email/handler/create_merge_request_handler.rb
@@ -55,11 +55,13 @@ module Gitlab
         end
 
         def merge_request_params
-          {
+          params = {
             source_project_id: project.id,
             source_branch: mail.subject,
             target_project_id: project.id
           }
+          params[:description] = message if message.present?
+          params
         end
       end
     end