bug#17753: Cygwin emacs-X11 core dump

[Markus Hoenicka]

Am 2014-10-09 10:56, schrieb Eli Zaretskii:
> > Date: Thu, 09 Oct 2014 10:17:47 +0200
> > From: Markus Hoenicka <markus.hoenicka@mhoenicka.de>
> > Cc: kbrown@cornell.edu, 17753@debbugs.gnu.org
> >
> > This time with gdb's crash message. FWIW, I was hitting the backspace
> > key to erase some characters from an XML document in a nXML buffer.
> >
> > Program received signal SIGSEGV, Segmentation fault.
> > face_for_char (f=0x100f45c48 <bss_sbrk_buffer+6331368>,
> > face=face@entry=0x0,
> >      c=101, pos=17134, object=object@entry=4304695346)
> >      at /usr/src/debug/emacs-24.3.93-3/src/fontset.c:917
> > 917         return face->ascii_face->id;
>
> Why do you think it's the same problem?  It looks very different to
> me, judging by the backtrace.

I should have been more verbose in my message. I didn't mean to imply 
this is the same problem. The backtrace which I sent today is of a new 
crash different from the ones I was talking about yesterday (it's an 
all-time high btw. Three crashes within 24 h). And yes, the backtraces 
do look different even to the untrained eye.

> > #0  0x00000001005a1673 in face_for_char (f=0x100f45c48
> > <bss_sbrk_buffer+6331368>, face=face@entry=0x0, c=101, pos=17134,
> > object=object@entry=4304695346)
> >      at /usr/src/debug/emacs-24.3.93-3/src/fontset.c:917
> > #1  0x0000000100428c1a in get_next_display_element
> > (it=it@entry=0x425c30)
> >      at /usr/src/debug/emacs-24.3.93-3/src/xdisp.c:7139
>
> What do the following GDB commands produce?
>
>  (gdb) thread 1
>  (gdb) frame 1
>  (gdb) print it->what
>  (gdb) print it->face_id
>  (gdb) print FRAME_FACE_CACHE (it->f)->used
>  (gdb) print face

(gdb) thread 1
[Switching to thread 1 (Thread 3788.0xb28)]
#0  face_for_char (f=0x100f45c48 <bss_sbrk_buffer+6331368>,
    face=face@entry=0x0, c=101, pos=17134, 
object=object@entry=4304695346)
    at /usr/src/debug/emacs-24.3.93-3/src/fontset.c:917
917         return face->ascii_face->id;
(gdb) frame 1
#1  0x0000000100428c1a in get_next_display_element 
(it=it@entry=0x425c30)
    at /usr/src/debug/emacs-24.3.93-3/src/xdisp.c:7139
7139              it->face_id = FACE_FOR_CHAR (it->f, face, c, pos, 
it->string);
(gdb) print it->what
$1 = IT_CHARACTER
(gdb) print it->face_id
$2 = 11
(gdb) print FRAME_FACE_CACHE (it->f)->used
No symbol "FRAME_FACE_CACHE" in current context.
(gdb) print face
$3 = (struct face *) 0x0


regards,
Markus
--
Markus Hoenicka
http://www.mhoenicka.de
AQ score 38