custom mode-line face makes Emacs freeze up

[Stephen Berman]

This bug report will be sent to the Free Software Foundation,
not to your local site managers!
Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the address@hidden mailing list.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

1. Start Emacs with -q -no-site-file.

2. Type `M-x customize-face' and at the prompt `mode-line'.

3. In the Custom buffer for mode-line face 
   a. check width and give it the value `narrow';
   b. check height and give it the value 120 in 1/10 pt;
   c. check underline and give it the value `on' (or `colored');
   d. check overline and give it the value `on' (or `colored').

4. Set for current session.

5. Invoke Ediff on any two files.

6. Now Emacs is frozen and consumes 95-99% of CPU.

The customizations in step 3 appear to be the minimum necessary to
induce this bug.  Leave out any one of them and Ediff runs without a
problem.  Also if the 1/10 point value of height is 130 or greater
there's no bug (with the default font family; with e.g. Helvetica the
bug is induced only by a value of 100 or less).

I've noticed this freeze up only when invoking Ediff.  The only thing
I've been able to do is kill Emacs externally, via top or with kill
when run in gdb, after interrupting.  When the freeze up happens
within a gdb session, there is no automatic debugging feedback.  After
interrupting I can get a backtrace, here's an example:

Program received signal SIGINT, Interrupt.
0x0813fcc6 in sort_overlays (overlay_vec=0xbfffd100, noverlays=1, w=0x0)
    at buffer.c:2885
2885              sortvec[j].overlay = overlay;
(gdb) ba
#0  0x0813fcc6 in sort_overlays (overlay_vec=0xbfffd100, noverlays=1, w=0x0)
    at buffer.c:2885
#1  0x081c9461 in get_char_property_and_overlay (position=8, prop=137813145, 
    object=141225508, overlay=0x0) at textprop.c:647
#2  0x081c9568 in Fget_char_property (position=8, prop=137813145, 
    object=141225508) at textprop.c:687
#3  0x080971b5 in handle_display_prop (it=0xbfffd2d0) at xdisp.c:3301
#4  0x0809627b in handle_stop (it=0xbfffd2d0) at xdisp.c:2590
#5  0x08095ccf in start_display (it=0xbfffd2d0, w=0x0, pos=
      {charpos = 1, bytepos = 1}) at xdisp.c:2287
#6  0x080a6436 in try_window (window=141095148, pos=
      {charpos = -1073753392, bytepos = 1}) at xdisp.c:12284
#7  0x080a45b4 in redisplay_window (window=141095148, just_this_one_p=0)
    at xdisp.c:12057
#8  0x080a1cbd in redisplay_window_0 (window=141095148) at xdisp.c:10619
#9  0x08187b94 in internal_condition_case_1 (
    bfun=0x80a1c90 <redisplay_window_0>, arg=141095148, handlers=137642301, 
    hfun=0x80a1c70 <redisplay_window_error>) at eval.c:1387
#10 0x080a1c41 in redisplay_windows (window=141095148) at xdisp.c:10598
#11 0x080a0e5f in redisplay_internal (preserve_echo_area=1) at xdisp.c:10180
#12 0x080a17de in redisplay_preserve_echo_area (from_where=2) at xdisp.c:10405
#13 0x0808aca4 in sit_for (sec=0, usec=100000, reading=0, display=1, 
    initial_display=1) at dispnew.c:6356
#14 0x0808ada7 in Fsit_for (seconds=137647030, milliseconds=0, nodisp=17201883)
    at dispnew.c:6419
#15 0x081897f0 in Ffuncall (nargs=2, args=0x83453b6) at eval.c:2747
#16 0x081b4c6f in Fbyte_code (bytestr=145005125, vector=1, 
    maxdepth=-1073749584) at bytecode.c:686
#17 0x08189b80 in funcall_lambda (fun=88, nargs=2, arg_vector=0xbfffe2e4)
    at eval.c:2923
#18 0x08189663 in Ffuncall (nargs=3, args=0xbfffe2e0) at eval.c:2793
#19 0x081b4c6f in Fbyte_code (bytestr=145004356, vector=2, 
    maxdepth=-1073749280) at bytecode.c:686
#20 0x08189b80 in funcall_lambda (fun=32, nargs=4, arg_vector=0xbfffe3f4)
    at eval.c:2923
#21 0x08189663 in Ffuncall (nargs=5, args=0xbfffe3f0) at eval.c:2793
#22 0x081b4c6f in Fbyte_code (bytestr=144886507, vector=4, 
    maxdepth=-1073749008) at bytecode.c:686
#23 0x08189b80 in funcall_lambda (fun=40, nargs=4, arg_vector=0xbfffe514)
    at eval.c:2923
#24 0x08189663 in Ffuncall (nargs=5, args=0xbfffe510) at eval.c:2793
#25 0x081b4c6f in Fbyte_code (bytestr=144885431, vector=4, 
    maxdepth=-1073748720) at bytecode.c:686
#26 0x08189b80 in funcall_lambda (fun=40, nargs=4, arg_vector=0xbfffe634)
    at eval.c:2923
#27 0x08189663 in Ffuncall (nargs=5, args=0xbfffe630) at eval.c:2793
#28 0x081b4c6f in Fbyte_code (bytestr=141026724, vector=4, 
    maxdepth=-1073748432) at bytecode.c:686
#29 0x08189b80 in funcall_lambda (fun=56, nargs=9, arg_vector=0xbfffe754)
    at eval.c:2923
#30 0x08189663 in Ffuncall (nargs=10, args=0xbfffe750) at eval.c:2793
#31 0x081b4c6f in Fbyte_code (bytestr=145112745, vector=9, 
    maxdepth=-1073748144) at bytecode.c:686
#32 0x08189b80 in funcall_lambda (fun=80, nargs=5, arg_vector=0xbfffe884)
    at eval.c:2923
#33 0x08189663 in Ffuncall (nargs=6, args=0xbfffe880) at eval.c:2793
#34 0x081b4c6f in Fbyte_code (bytestr=145112042, vector=5, 
    maxdepth=-1073747840) at bytecode.c:686
#35 0x08189b80 in funcall_lambda (fun=48, nargs=2, arg_vector=0xbfffe9a4)
    at eval.c:2923
#36 0x08189663 in Ffuncall (nargs=3, args=0xbfffe9a0) at eval.c:2793
#37 0x08188f8c in Fapply (nargs=2, args=0xbfffea20) at eval.c:2189
#38 0x081893bc in apply1 (fn=138197745, arg=141225504) at eval.c:2497
#39 0x08184f55 in Fcall_interactively (function=138197745, 
    record_flag=137615113, keys=137671948) at callint.c:407
#40 0x08130e6e in Fcommand_execute (cmd=138197745, record_flag=137615113, 
    keys=137615065, special=0) at keyboard.c:9724
#41 0x08131072 in Fexecute_extended_command (prefixarg=137615065)
    at keyboard.c:9821
#42 0x081897f0 in Ffuncall (nargs=2, args=0x833d6d9) at eval.c:2747
#43 0x081852c2 in Fcall_interactively (function=137672393, 
    record_flag=17201883, keys=137671948) at callint.c:863
#44 0x08130e6e in Fcommand_execute (cmd=137672393, record_flag=137615065, 
    keys=137615065, special=0) at keyboard.c:9724
#45 0x08125563 in command_loop_1 () at keyboard.c:1779
#46 0x08187a8d in internal_condition_case (bfun=0x8125170 <command_loop_1>, 
    handlers=137676041, hfun=0x8124c70 <cmd_error>) at eval.c:1346
#47 0x08124f9b in command_loop_2 () at keyboard.c:1309
#48 0x081875ca in internal_catch (tag=0, func=0x8124f80 <command_loop_2>, 
    arg=137615065) at eval.c:1107
#49 0x08124f57 in command_loop () at keyboard.c:1288
#50 0x081249a2 in recursive_edit_1 () at keyboard.c:981
#51 0x08124aef in Frecursive_edit () at keyboard.c:1042
#52 0x08123233 in main (argc=1, argv=0xbffff4c4) at emacs.c:1687


In GNU Emacs 21.3.50.2 (i686-pc-linux-gnu, GTK+ Version 2.2.3)
 of 2004-10-18 on feldmann
configured using `configure '--with-x-toolkit=gtk''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: C
  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_US
  locale-coding-system: iso-latin-1
  default-enable-multibyte-characters: t

Major mode: Group

Minor modes in effect:
  gnus-topic-mode: t
  gnus-undo-mode: t
  show-paren-mode: t
  tabbar-mode: t
  auto-compression-mode: t
  display-time-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: identity

Recent input:
y M-x g u <return> J j y <down> <down> <down> M-g <up> 
<up> <up> M-g <down> <down> M-g <up> <up> M-g <down> 
<down> <down> M-g <return> a c u s t o m SPC m o d 
e ö l <backspace> <backspace> - l i n e SPC f a c e 
SPC i n c <backspace> d u c e s SPC i n f i n i t e 
SPC l e <backspace> o o p <down> <down> <down> C-x 
k <return> y e s <return> Q y M-x r e p o <tab> r <tab> 
<return>

Recent messages:
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