Steps to replicate the issue (include links if applicable):
- Set up MediaWiki with MySQL
- Enable file upload and add additional allowed extension
- $wgEnableUploads = true;
- $wgFileExtensions = [ 'png', 'gif', 'jpg', 'jpeg', 'webp', 'ttf' ];
- If working in development mode, disable strict warnings $wgDBStrictWarnings = false;, otherwise enable strict SQL Mode $wgSQLMode = 'STRICT_ALL_TABLES';.
- Upload file with a non-standard extension, eg. .ttf.
- You can notice that the file is saved in the image table with ''/0 value in img_major_mime column
- Now try to delete the file
What happens?:
There is an error, and the file cannot be deleted:
Wikimedia\Rdbms\DBQueryError from line 1627 of /includes/libs/rdbms/database/Database.php: Error 1265: Data truncated for column 'fa_major_mime' at row 1 Function: LocalFileDeleteBatch::doDBInserts Query: INSERT INTO `filearchive` ...
MediaWiki tried to move the record from the image table to the filearchive table, but it was impossible because fa_major_mime is an enum, and ''/0 value is not allowed when MySQL is configured to work in a strict mode.
The img_major_mime column in the image table has a similar enum, but image upload works, because the code appends IGNORE to the INSERT statement, and MySQL converts the not-allowed enum value to ''/0`.
What should have happened instead?:
The file should be deleted.
Software version (skip for WMF-hosted wikis like Wikipedia):
Latest code from the master, but also older versions, eg. 1.39.
I submitted two patches that could fix this issue:
- Stop producing data with invalid enum values, by using an unknown value for cases when the calculated mime is different than allowed by the database schema: https://gerrit.wikimedia.org/r/c/mediawiki/core/+/992148
- Allow deletion of files with invalid img_major_mime values, by using IGNORE in the INSERT to filearchive table statement. It could alternatively be replaced by a database update fixing bad records: https://gerrit.wikimedia.org/r/c/mediawiki/core/+/992150