Approval rules for merge requests containing only code comments should be configurable separately
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## Problem to Solve
Merge request approval rules are currently configured on a per-project basis. This makes it challenging to move MRs to additional branches when something might not require approvals since it's already been through that process.
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### Proposal
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Maintainers should be able to configure separate approval rules for merge requests that only contain code comments. Comments are non-functional changes, and as a result may not require as rigorous of an approval process; requiring full approvals in these cases is inefficient, unless the maintainer wants to enforce specific comment quality standards.
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