Fixes: https://github.com/go-gitea/gitea/issues/36152
Enable the `nilnil` linter while adding `//nolint` comments to existing
violations. This will ensure no new issues enter the code base while we
can fix existing issues gradually.
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Mainly for MySQL/MSSQL.
It is important for Gitea to use case-sensitive database charset
collation. If the database is using a case-insensitive collation, Gitea
will show startup error/warning messages, and show the errors/warnings
on the admin panel's Self-Check page.
Make `gitea doctor convert` work for MySQL to convert the collations of
database & tables & columns.
* Fix#28131
## ⚠️ BREAKING ⚠️
It is not quite breaking, but it's highly recommended to convert the
database&table&column to a consistent and case-sensitive collation.