bug#28176: 26.0.50; Emacs hangs on entering a specific article in gnus

[Charles A. Roelli]

> From: Sam Steingold <sds@gnu.org>
> Date: Wed, 23 Aug 2017 09:34:53 -0400
> Cc: Eli Zaretskii <eliz@gnu.org>, 28176@debbugs.gnu.org,      Noam Postavsky 
> <npostavs@users.sourceforge.net>
> 
> if you use gdb, you can tap into the src/.gdbinit and its "x" and "p" 
> commands.
> 

Seems like this may be a side effect of a recent change adding GIF
support in macOS (I'm CCing the author, Alan Third).

In nsimage.m:111 (ns_load_image), there is this call to add_to_log:

add_to_log ("Unable to set index %d for image %s", index, img->spec);

but img->spec is a Lisp_Object:

(gdb) ptype img->spec
type = struct Lisp_Object {
    EMACS_INT i;
}

Maybe "%s" doesn't cover Lisp_Objects?  At any rate, that seems to be
what the error message is about.