Re: Any success with emacs 2.1.4 under cygwin 1.5.21?

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 28 Sep 2006 17:49:52 -0400
> From: "Sean M. Paus" <spaus@pobox.com>
> 
> I've recently upgraded my cygwin installation to 1.5.21.  Since then, I
> have had no luck getting emacs to run.  I've tried the stock 21.2 that
> comes with the cygwin distribution, the test 21.3 that was posted a
> while back, and I've even downloaded and (well half) built the latest
> sources from the emacs CVS repository.
> 
> The problem is that emacs just hangs and takes up gobs of CPU.  I
> ultimately tracked this down to a tight infinite loop in
> _malloc_internal (gmalloc.c).  For some reason, align (also in
> gmalloc.c) is returning a pointer that is smaller than _heapbase.  The
> calculation to determine what block the newly requested memory is in
> (BLOCK(result+size)) returns a ridiculously huge number.  Since
> _malloc_internal incrementally doubles the new size of the heap until
> the requested memory fits, at some point the multiplication overflows
> and newsize gets a value of 0.  Since 0 * 2 is always zero, the test for
> BLOCK(result+size) > newsize will always succeed and _malloc_internal
> gets stuck in a tight loop multiplying 0 by 2 forever.

Thanks for investigating the problem, but this is not a good place to
post such reports.  Please use emacs-devel@gnu.org, since the problem
seems to exist in the CVS code as well (or did I misunderstand?).

Also, you may wish to search the archives of emacs-devel and
emacs-pretest-bug mailing lists, as I think something similar was
reported in the past.

(I myself don't use Cygwin, so I cannot help you more at this time.)