For some old merge requests, we don't have enough information to figure out the
old blob and the new blob for the file. This means that we can't highlight the
diff correctly, but we can still display it without highlighting.

We didn't have a fallback case before, because we believed the conditions were
exhaustive. They weren't, so we can always fallback to not previewing.

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

Remove superfluous lib: true, type: redis, service: true, models: true, services: true, no_db: true, api: true

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

Use the EnforcedStyleForMultiline: no_comma option.

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

This reverts commit 96bef54154e669f9a3e92c3a4bc76c0be3a52e48.

Reason for renaming is to comply with naming convention of services in
codebase.

Backport changes from the EE-only squash implementation, which would
otherwise conflict when merge CE into EE.

<https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1024>

Ports changes from https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/642 back into CE

Don't try to highlight and cache files hidden by .gitattributes entries.

Steps to reproduce:

1. Start with a repo with an image
2. Add a commit to delete the image
3. Add another commit to replace the image with another image

In a diff comparison, we really just compare about what the image was before the diff, not
the direct parent of the last commit. This MR fixes that.

Closes #3893, gitlab-org/gitlab-ee#678

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

The initial commit doesn't have a parent, so explicitly pass the blank
SHA and handle that when calculating the position.

So we have raw_diffs too

This reverts commit 530f5158.

See !4892.

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