bug#49261: 28.0.50; File Locking Breaks Presumptuous Toolchains

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Stefan Monnier <monnier@iro.umontreal.ca>,  michael.albinus@gmx.de,
>   ncaprisunfan@gmail.com,  49261@debbugs.gnu.org, Paul Eggert
>  <eggert@cs.ucla.edu>
> Date: Sat, 10 Jul 2021 19:15:53 +0200
> 
> >> 731          return lisp_h_XLP (o);
> >> (gdb) bt
> >> #0  0x00005555556f0549 in AREF (idx=6988131860, array=XIL(0x7ffff1bd901d))
> >>     at lisp.h:731
> >> #1  HASH_KEY (idx=3494065930, h=0x7ffff1bd8f98) at lisp.h:2374
> >> #2  hash_lookup
> >>     (h=0x7ffff1bd8f98, key=XIL(0x555555c76c64), hash=hash@entry=0x0)
> >>     at fns.c:4479
> 
> Well, the segfault is in this:
> 
>   for (i = HASH_INDEX (h, start_of_bucket); 0 <= i; i = HASH_NEXT (h, i))
>     {
> 
> and you can see that idx (i.e., i here) is 3494065930, which is a very
> unusual value for idx -- it's usually below 2K.  So it can't really be
> anything other than a memory corruption issue, I think?

Yes, but why? and in which hash-table?