GitHub Fork Compare Fix per Nico

GitHub assumes every fork exists to contribute upstream. Its Contribute menu, Compare & pull request banner, and N commits ahead link therefore open comparisons against the upstream repository.

That is useful when you are contributing back. It is wrong when your fork has its own default branch and pull requests.

GitHub Fork Compare Fix changes this only in repositories you enable:

• Compare and pull request links stay inside your fork and use its default branch as the base.
• The branch info bar and Contribute menu show commit counts against your fork's default branch.
• The N commits behind link still points upstream, where it belongs.
• An optional redirect catches upstream compare pages after you open them.
• Enable one repository from the toolbar, or manage owner/repo and owner/* patterns in the options page.

Repositories you do not enable keep GitHub's usual behavior, so forks used for upstream contributions are unaffected.

Privacy

The extension has no telemetry and asks for no separate account or API token. It runs only on github.com. Requests go only to GitHub through your existing session. Your list of enabled repositories stays in browser extension storage.

Source code under GPL-3.0:
https://github.com/D3SOX/gh-fork-compare-fix