Eliminate N+1 queries in loading namespaces for every issuable in milestones

If we rely on the helper functions in GitlabRoutingHelper for merge_request_path, we end up calling a database query to look up the Namespace association for every merge request since entity.project.namespace is called. By reusing the project defined in the controller, we avoid that problem.

Partial fix to #27387 (closed)

mentioned in issue #27387 (closed)

@stanhu thanks, good catch! One question.

assigned to @stanhu

added 1 commit

• f081e781 - Optimize project namespace lookup for milestones and add specs

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mentioned in merge request !10872 (merged)

resolved all discussions

added 1 commit

• 68bb2a53 - Optimize project namespace lookup for milestones and add specs

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assigned to @smcgivern

approved this merge request

enabled an automatic merge when the pipeline for 68bb2a53 succeeds

merged

mentioned in commit 3ac4ef22

mentioned in commit 3e40fb27

Picked into 9-1-stable, will go into 9.1.1.

mentioned in issue #31285 (closed)

mentioned in merge request !12670 (merged)