Create detached merge request pipelinespersist-fulll-ref-path-for-mr-pipelines

By using `refs/merge-requests/:iid/head`

ok

ok

Improve naming nicely

Add nice tests

add nice tests

fix some more

revert

3 files changed, 10 insertions, 1 deletions

diff --git a/lib/gitlab/ci/pipeline/chain/command.rb b/lib/gitlab/ci/pipeline/chain/command.rb
index bf9f03f6134..03af99ba9a5 100644
--- a/lib/gitlab/ci/pipeline/chain/command.rb
+++ b/lib/gitlab/ci/pipeline/chain/command.rb
@@ -33,6 +33,13 @@ module Gitlab
             end
           end
 
+          def merge_request_ref_exists?
+            strong_memoize(:merge_request_ref_exists) do
+              MergeRequest.merge_request_ref?(origin_ref) &&
+                project.repository.ref_exists?(origin_ref)
+            end
+          end
+
           def ref
             strong_memoize(:ref) do
               Gitlab::Git.ref_name(origin_ref)
diff --git a/lib/gitlab/ci/pipeline/chain/validate/abilities.rb b/lib/gitlab/ci/pipeline/chain/validate/abilities.rb
index ebd7e6e8289..aaa3daddcc5 100644
--- a/lib/gitlab/ci/pipeline/chain/validate/abilities.rb
+++ b/lib/gitlab/ci/pipeline/chain/validate/abilities.rb
@@ -44,6 +44,8 @@ module Gitlab
                 access.can_update_branch?(@command.ref)
               elsif @command.tag_exists?
                 access.can_create_tag?(@command.ref)
+              elsif @command.merge_request_ref_exists?
+                access.can_update_branch?(@command.merge_request.source_branch)
               else
                 true # Allow it for now and we'll reject when we check ref existence
               end
diff --git a/lib/gitlab/ci/pipeline/chain/validate/repository.rb b/lib/gitlab/ci/pipeline/chain/validate/repository.rb
index 9c6c2bc8e25..8f5445850d7 100644
--- a/lib/gitlab/ci/pipeline/chain/validate/repository.rb
+++ b/lib/gitlab/ci/pipeline/chain/validate/repository.rb
@@ -9,7 +9,7 @@ module Gitlab
             include Chain::Helpers
 
             def perform!
-              unless @command.branch_exists? || @command.tag_exists?
+              unless @command.branch_exists? || @command.tag_exists? || @command.merge_request_ref_exists?
                 return error('Reference not found')
               end