Closes #28857

Previously, this would issue a query for each unique `diff_refs_or_sha`
passed. This was because we didn't want to load other MR diffs into memory, as
they had some very large columns.

Now they are actually very small, and it's more efficient to just load them all
at once and do the finding in Ruby.

Douwe Maan authored 6 years ago and Mark Fletcher committed 6 years ago

Server Side Request Forgery in Services and Web Hooks

See merge request gitlab/gitlabhq!2337

This is a first step to decouple pipeline from YAML processing. It
reduces the coupling by removing some methods that introduce coupling
and by moving logic into separate chain element that is being used to
populate pipelines with stages and builds.

The specs are based on a schema version that doesn't know about
`internal_ids` table. However, the actual code being execute relies on
it.

Previously, we kept them all in the cache. We don't need the highlight results
for older diffs - if someone does view that (which is rare), we can do the
highlighting on the fly.

Prior to this change, this method was called add_namespace, which broke
the CRUD convention and made it harder to grep for what I was looking
for. Given the change was a find and replace kind of fix, this was
changed without opening an issue and on another feature branch.

If more dynamic calls are made to add_namespace, these could've been
missed which might lead to incorrect bahaviour. However, going through
the commit log it seems thats not the case.

We only allow users that can merge the merge request to push to the
fork.