Gitblame: fix fatal error on `chdir()` when `basepath` is set and phpcs is run from subdir

[jrfnl]

Description

The Reporter::prepareFileReport() method strips the basepath off the file name for the $report['filename'].

https://github.com/squizlabs/PHP_CodeSniffer/blob/276f68cc74a3e4e1855bab6d01f0089337d00ae0/src/Reporter.php#L337

While this is fine in most cases, for "blame" reports, the full path is needed.

This changes the path passed to the getBlameContent() method in subclasses of the VersionControl class to the full path, which fixes the fatal error for the Gitblame report (and probably similar/related errors in the Hgblame and the Svnblame reports, but I don't have any repos to test this on).

Suggested changelog entry

Fixed bug #3854 : Fatal error when using Gitblame report in combination with basepath and running from project subdirectory

Related issues/external references

Fixes #3854

Loosely related to #3809

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
  • [ ] This change is only breaking for integrators, not for external standards or end-users.
• [ ] Documentation improvement

[jrfnl]

Closing as replaced by https://github.com/PHPCSStandards/PHP_CodeSniffer/pull/67

[jrfnl]

FYI: this fix is included in today's PHP_CodeSniffer 3.8.0 release.

As per #3932, development on PHP_CodeSniffer will continue in the PHPCSStandards/PHP_CodeSniffer repository. If you want to stay informed, you may want to start "watching" that repo (or watching releases from that repo).