bug#39962: 27.0.90; Crash in Emacs 27.0.90

[Pieter van Oostrum]

I think we got stuck here. I don't think the problem is in the actual code that 
Emacs was executing at this point. Rather, the problem was that a marker was 
corrupted (m->charpos == 0).
That could have happened at a completely unrelated place. I have been trying to 
look in insdel.c and editfns.c to find something unusual, but to no avail.

I have also looked into the chain of markers in the buffer. There are quite a 
lot of them, and I haven't finished it, but what I have seen looks normal.

On the other hand, every edit action on the buffer must have adjusted the 
markers, so the corruption probably did not occur a long time ago.

Do you have any suggestion on what more to inspect?
-- 
Pieter van Oostrum
www: http://pieter.vanoostrum.org/
PGP key: [8DAE142BE17999C4]