Infinite loop when running gtags in Emacs

[Matthew Leach]

Hello,

I'm trying to run 'gtags' in the src/ directory of the latest Emacs
development version. However, I seem to be running into an infinite
loop. Running gtags through gdb, there seems to be a problem with
mpool_look().

The for loop on line 426 of mpool.c is where it seems to be getting
stuck. Below is a dump of some gdb commands that will hopefully show why
we are stuck:

(gdb) p bp
$1 = (BKT *) 0x54f70
(gdb) p bp->pgno 
$2 = 1
(gdb) p pgno
$3 = 129
(gdb) p bp->hq.cqe_next
$4 = (struct _bkt *) 0x54f70
(gdb) p head
$5 = (struct _hqh *) 0x52b28

The BKT* at 0x54f70 is self-referential. Any ideas how we could have
ended up in this state? If it helps, I'm running this on a armv7l
system.

Thanks,
--
Matt