Fix CI_COMMIT_REF_NAME and SLUG variable

With Pipelines for Merge Requests feature, users cannout keep using
$CI_COMMIT_REF_NAME and _SLUG predefined variables for dynamic
environments. We fix this problem by explicitly looking at the source
ref.

3 files changed, 14 insertions, 4 deletions

diff --git a/app/models/ci/bridge.rb b/app/models/ci/bridge.rb
index 0d8d7d95791..644716ba8e7 100644
--- a/app/models/ci/bridge.rb
+++ b/app/models/ci/bridge.rb
@@ -4,6 +4,7 @@ module Ci
   class Bridge < CommitStatus
     include Ci::Processable
     include Ci::Contextable
+    include Ci::PipelineDelegator
     include Importable
     include AfterCommitQueue
     include HasRef
@@ -13,8 +14,6 @@ module Ci
     belongs_to :trigger_request
     validates :ref, presence: true
 
-    delegate :merge_request_event?, to: :pipeline
-
     def self.retry(bridge, current_user)
       raise NotImplementedError
     end
diff --git a/app/models/ci/build.rb b/app/models/ci/build.rb
index e5236051118..5a2ead41578 100644
--- a/app/models/ci/build.rb
+++ b/app/models/ci/build.rb
@@ -6,6 +6,7 @@ module Ci
     include Ci::Processable
     include Ci::Metadatable
     include Ci::Contextable
+    include Ci::PipelineDelegator
     include TokenAuthenticatable
     include AfterCommitQueue
     include ObjectStorage::BackgroundMove
@@ -49,8 +50,6 @@ module Ci
     delegate :terminal_specification, to: :runner_session, allow_nil: true
     delegate :gitlab_deploy_token, to: :project
     delegate :trigger_short_token, to: :trigger_request, allow_nil: true
-    delegate :merge_request_event?, :merge_request_ref?,
-             :legacy_detached_merge_request_pipeline?, to: :pipeline
 
     ##
     # Since Gitlab 11.5, deployments records started being created right after
diff --git a/app/models/ci/pipeline.rb b/app/models/ci/pipeline.rb
index bbd21eb0e78..2b7835d7fab 100644
--- a/app/models/ci/pipeline.rb
+++ b/app/models/ci/pipeline.rb
@@ -759,6 +759,18 @@ module Ci
       user == current_user
     end
 
+    def source_ref
+      if triggered_by_merge_request?
+        merge_request.source_branch
+      else
+        ref
+      end
+    end
+
+    def source_ref_slug
+      Gitlab::Utils.slugify(source_ref.to_s)
+    end
+
     private
 
     def ci_yaml_from_repo