This PR replaces the existing `skip-to` approach for rendering large diffs with paging over the changeset of a git diff, enabling a more efficient way to render the compare view for PR, compare, and commit views.
## Problem
When a user opens a compare page for a large range of commits, Forgejo calculates the entire diff (potentially multiple times) Which consumes significant CPU time on the server and produces an enormous amount of HTML for the browser to parse and display. At some point the page becomes unusable or fails to load entirely.
The previous `skip-to` approach attempted to mitigate this by allowing the user to jump to a specific file or section within the diff. However, this still required the diff process and prepare the full changeset up to that point. It did not fundamentally bound the amount of work done per request: the server could still spend excessive time calculating the Diff. As a result, `skip-to` was not a reliable solution for very large diffs.
TLDR; `--skip-to` is an output-ordering/presentation option, not a performance optimization. [git docs](https://git-scm.com/docs/diff-options#Documentation/diff-options.txt---skip-tofile)
## Solution
This change introduces paging over the changeset of a git diff. Rather than relying on `skip-to`, the diff is now split into manageable pages. Only a subset of the changed files is fetched, highlighted, and rendered at a time.
### Tests for Go changes
- I added test coverage for Go changes...
- [x] in their respective `*_test.go` for unit tests.
- [x] in the `tests/integration` directory if it involves interactions with a live Forgejo server.
- I ran...
- [x] `make pr-go` before pushing
### Documentation
- [ ] I created a pull request [to the documentation](https://codeberg.org/forgejo/docs) to explain to Forgejo users how to use this change.
- [x] I did not document these changes and I do not expect someone else to do it.
### Release notes
- [x] This change will be noticed by a Forgejo user or admin (feature, bug fix, performance, etc.). I suggest to include a release note for this change.
- [ ] This change is not visible to a Forgejo user or admin (refactor, dependency upgrade, etc.). I think there is no need to add a release note for this change.
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## Release notes
<!--URL:https://codeberg.org/forgejo/forgejo-->
- Security features
- [PR](https://codeberg.org/forgejo/forgejo/pulls/12808): <!--number 12808 --><!--line 0 --><!--description ZG9uJ3QgcmVuZGVyIGxhcmdlIGNvbXBhcmUgZGlmZg==-->don't render large compare diff<!--description-->
<!--end release-notes-assistant-->
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/12808
Reviewed-by: Mathieu Fenniak <mfenniak@noreply.codeberg.org>
Related to #2773
Related to Refactor URL detection [gitea#29960](https://github.com/go-gitea/gitea/pull/29960)
Related to Refactor external URL detection [gitea#29973](https://github.com/go-gitea/gitea/pull/29973)
I added a bunch of tests to `httplib.TestIsRiskyRedirectURL` and some cases should be better handled (however it is not an easy task).
I also ported the removal of `utils.IsExternalURL`, since it prevents duplicated (subtle) code.
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/3167
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: oliverpool <git@olivier.pfad.fr>
Co-committed-by: oliverpool <git@olivier.pfad.fr>
Change all license headers to comply with REUSE specification.
Fix#16132
Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>
This PR updates golangci-lint to the latest version 1.31.0.
The upgrade introduced a new check for which I've fixed or disabled most cases.
Signed-off-by: kolaente <k@knt.li>
Replace all calls to os.Remove/os.RemoveAll by retrying util.Remove/util.RemoveAll and remove circular dependencies from util.
Fix#12339
Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: silverwind <me@silverwind.io>
