insdel.c crash with 21.2.44

I've been getting intermittent crashes in insdel.c, with a failed assertion: Fatal error: assertion failed, file insdel.c, line 1529, bytpos >= BI_BUF_BEGV (buf) && bytpos <= BI_BUF_ZV (buf) I can recreate this on demand by simply opening the attached file. Note that if the file size is jittered, the crash goes away. Could someone try this and let me know if it's repeatable? If not, there is the chance that I poked at a bad thing somewhere while fixing the latest round of antialiasing patches... I've also attached the Installation file for my install as well. - Vlad