wp_text_diff() out of memory with 10GB memory limit on certain revisions

[justjack1]

Hi,

I have identified a bug with wp_text_diff on a blank WP install on PHP 7.2.8 and 7.3.12
The bug causes the system to run out of memory no matter how much is available. I found it while trying to edit some revisions. The texts are large (50KB), maybe it has something to do with it.

To replicate the bug you need to use this code. I will provide the files.

<?php
        $content_from = file_get_contents( ABSPATH . '/content_from.txt' );
        $content_to = file_get_contents( ABSPATH . '/content_to.txt' );
        $diff = wp_text_diff( $content_from, $content_to, [] );

}}}

[justjack1]

Archive contains two files with HTML text to be used in testing the bug