Hello,

When an old revision of a page is selected in the history, edited and published, it seems that AbuseFilter initializes old_wikitext with the text of this old revision instead of the last published revision before the current edit (this also affects related variables such as added_lines).

Moreover, when an old revision is edited and published without any change, the edit is not filtered at all (because of the test "if ( strcmp( $oldtext, $text ) == 0 ) ... return true;" in the function onEditFilterMerged of AbuseFilter.hooks.php, I guess).

This makes possible to circumvent any filter as soon as a "bad" revision exists in the page history. Moreover, it is hard to understand afterwards why such edits are not filtered, as they trigger filters normally in the test interface.

Best regards

Version: unspecified
Severity: normal