23.0.60; Segmentation fault in FcPatternDestroy when deleting frame

[Lawrence Mitchell]

The following recipe causes a segfault in FcPatternDestroy, called from
font_clear_cache when deleting an X frame created by emacsclient when
the original emacs instance was started with -nw.

This is with a checkout from today for which the most recent commit was:

| Author: Jan Djärv <address@hidden>
| Date:   Mon Feb 18 08:08:23 2008 +0000

|     (Fx_show_tip): Set string to " " if empty.


1) emacs -nw -Q -l "bug.el" ; See included file below.

In another terminal:
2) emacsclient -c           ; Create an X frame.

3) C-x 5 0                  ; delete the frame

4) Fatal error (11)Segmentation fault

--8<---------------cut here---------------start------------->8---
(server-start)

(custom-set-faces
 '(bold ((t (:family "mono"))))
 '(default ((t (:family "mono"))))
 '(mode-line ((t (:inherit default))))
 '(mode-line-inactive ((t (:inherit bold))))
 )
--8<---------------cut here---------------end--------------->8---

backtrace:
Program received signal SIGSEGV, Segmentation fault.
0x00530b64 in FcPatternDestroy () from /usr/lib/libfontconfig.so.1
(gdb) where
#0  0x00530b64 in FcPatternDestroy () from /usr/lib/libfontconfig.so.1
#1  0x0819df8d in font_clear_cache (f=0x85f0098, cache=147336045, 
driver=0x8333c40) at /scratch/s0198183/src/emacs/src/font.c:2292
#2  0x0819f185 in font_update_drivers (f=0x85f0098, new_drivers=137611465) at 
/scratch/s0198183/src/emacs/src/font.c:2230
#3  0x0805d7b8 in Fdelete_frame (frame=140443804, force=137611465) at 
/scratch/s0198183/src/emacs/src/frame.c:1495
#4  0x08159f67 in Ffuncall (nargs=1, args=0xbfea5ef0) at 
/scratch/s0198183/src/emacs/src/eval.c:3028
#5  0x08156e87 in Fcall_interactively (function=137646673, 
record_flag=137611465, keys=137649884) at 
/scratch/s0198183/src/emacs/src/callint.c:842
#6  0x08159f67 in Ffuncall (nargs=4, args=0xbfea60f0) at 
/scratch/s0198183/src/emacs/src/eval.c:3028
#7  0x0815a094 in call3 (fn=137774289, arg1=137646673, arg2=137611465, 
arg3=137611465) at /scratch/s0198183/src/emacs/src/eval.c:2855
#8  0x080fcf76 in Fcommand_execute (cmd=137646673, record_flag=137611465, 
keys=137611465, special=137611465) at 
/scratch/s0198183/src/emacs/src/keyboard.c:10445
#9  0x08104d1a in command_loop_1 () at 
/scratch/s0198183/src/emacs/src/keyboard.c:1910
#10 0x081582fa in internal_condition_case (bfun=0x81049b4 <command_loop_1>, 
handlers=137655697, hfun=0x80fd81c <cmd_error>) at 
/scratch/s0198183/src/emacs/src/eval.c:1494
#11 0x080f84d2 in command_loop_2 () at 
/scratch/s0198183/src/emacs/src/keyboard.c:1370
#12 0x08157fd9 in internal_catch (tag=137650545, func=0x80f84b4 
<command_loop_2>, arg=137611465) at /scratch/s0198183/src/emacs/src/eval.c:1230
#13 0x080f82e4 in command_loop () at 
/scratch/s0198183/src/emacs/src/keyboard.c:1349
#14 0x080f8380 in recursive_edit_1 () at 
/scratch/s0198183/src/emacs/src/keyboard.c:958
#15 0x080f849f in Frecursive_edit () at 
/scratch/s0198183/src/emacs/src/keyboard.c:1020
#16 0x080f7659 in main (argc=5, argv=0xbfea6774) at 
/scratch/s0198183/src/emacs/src/emacs.c:1786

Lisp Backtrace:
"delete-frame" (0xbfea5ef4)
"call-interactively" (0xbfea60f4)

(gdb) bt full
#0  0x00530b64 in FcPatternDestroy () from /usr/lib/libfontconfig.so.1
No symbol table info available.
#1  0x0819df8d in font_clear_cache (f=0x85f0098, cache=147336045, 
driver=0x8333c40) at /scratch/s0198183/src/emacs/src/font.c:2292
        p = (struct Lisp_Save_Value *) 0x8baa148
        font = Variable "font" is not available.


In GNU Emacs 23.0.60.4 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2008-02-18 on lamacq.ph.ed.ac.uk
Windowing system distributor `The X.Org Foundation', version 11.0.60802000
configured using `configure  
'--prefix=/scratch/s0198183/applications/emacs-trunk/' '--enable-font-backend' 
'--with-xft' '-C''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_GB.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Cheers,

Lawrence
-- 
Lawrence Mitchell <address@hidden>