Re: PATCH: fix for memory corruption and eventual crash in print.c

[YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>]

>>>>> On Sat, 5 Jul 2008 21:11:14 -0700, "Ami Fischman" <ami@fischman.org> said:

> src/print.c:print_object() has this code:

>    1570       if (NILP (Vprint_circle) && NILP (Vprint_gensym))
> [...]
>    1581           being_printed[print_depth] = obj;
> [...]
>    1611   print_depth++;
>    1612
>    1613   /* See similar code in print_preprocess.  */
>    1614   if (print_depth > PRINT_CIRCLE)
>    1615     error ("Apparently circular structure being printed");

> Note that being_printed[print_depth] is assigned to /before/ print_depth is
> checked for exceeding PRINT_CIRCLE (the declared size of being_printed).

This reminds me of a similar buffer overrun that had existed in
`print_preprocess' also with respect to `being_printed'.

  http://lists.gnu.org/archive/html/emacs-devel/2004-07/msg00146.html

I think a fix for `print_object' should go to the EMACS_22_BASE branch
as well as the trunk so it may not be missed.  Another candidate for
the inclusion to the EMACS_22_BASE branch would be the PNG background
color bit-depth fix below:

2008-05-09  Chong Yidong  <cyd@stupidchicken.com>

	* image.c (png_load): Use correct bit-depth for setting background
	color.

				     YAMAMOTO Mitsuharu
				mituharu@math.s.chiba-u.ac.jp