Merge branch '23234-deleting-a-milestone-removes-source-branch-deletion-options-of-associated-merge-requests' into 'master'

Maintain "force_remove_source_branch" options on Merge Request unless specified

Fixes a problem where Merge Requests were losing the state associated with the flag to remove the source branch upon merge

* Closes #23234
* Closes #23191
* Closes #19351

See merge request !6817

Signed-off-by: Rémy Coutable <remy@rymai.me>

3 files changed, 16 insertions, 1 deletions

diff --git a/CHANGELOG b/CHANGELOG
index ccf71700e1a..f849d6eec64 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -6,6 +6,7 @@ v 8.12.7
   - Use gitlab-markup gem instead of github-markup to fix `.rst` file rendering. !6659
   - Prevent flash alert text from being obscured when container is fluid. !6694
   - Fix JS bug with select2 because of missing `data-field` attribute in select box. !6812
+  - Do not alter 'force_remove_source_branch' options on MergeRequest unless specified. !6817
 
 v 8.12.6
   - Update mailroom to 0.8.1 in Gemfile.lock  !6814
diff --git a/app/services/merge_requests/update_service.rb b/app/services/merge_requests/update_service.rb
index f14f9e4b327..0c158bf4477 100644
--- a/app/services/merge_requests/update_service.rb
+++ b/app/services/merge_requests/update_service.rb
@@ -15,7 +15,9 @@ module MergeRequests
         params.except!(:target_branch, :force_remove_source_branch)
       end
 
-      merge_request.merge_params['force_remove_source_branch'] = params.delete(:force_remove_source_branch)
+      if params[:force_remove_source_branch].present?
+        merge_request.merge_params['force_remove_source_branch'] = params.delete(:force_remove_source_branch)
+      end
 
       update(merge_request)
     end
diff --git a/spec/services/merge_requests/update_service_spec.rb b/spec/services/merge_requests/update_service_spec.rb
index 33db34c0f62..aacf95d0b63 100644
--- a/spec/services/merge_requests/update_service_spec.rb
+++ b/spec/services/merge_requests/update_service_spec.rb
@@ -104,6 +104,18 @@ describe MergeRequests::UpdateService, services: true do
         expect(note).not_to be_nil
         expect(note.note).to eq 'Target branch changed from `master` to `target`'
       end
+
+      context 'when not including source branch removal options' do
+        before do
+          opts.delete(:force_remove_source_branch)
+        end
+
+        it 'maintains the original options' do
+          update_merge_request(opts)
+
+          expect(@merge_request.merge_params["force_remove_source_branch"]).to eq("1")
+        end
+      end
     end
 
     context 'todos' do