Re: A crash in a gnus group with indic script in content and headers

[Manoj Srivastava <srivasta@ieee.org>]

On Tue, Oct 21 2008, Kenichi Handa wrote:

> In article <87mygy607z.fsf@anzu.internal.golden-gryphon.com>, Manoj Srivastava <srivasta@ieee.org> writes:
>
>> Hi,
>>         I see these crashes frequently in indian mailing lists via
>>  gmane -- English language mailing lists (probably because of some indic
>>  language content -- I have to delete the messages, usually).
> [...]
>> Program received signal SIGSEGV, Segmentation fault.
>> [Switching to Thread 0x7f74bbe48770 (LWP 8898)]
>> 0x00000000005bb6fc in ftfont_otf_features (gsub_gpos=0x62633f0) at /usr/local/git/emacs/src/ftfont.c:1365
>> 1365                  OTF_TAG_SYM (sym, gsub_gpos->FeatureList.Feature[l].FeatureTag);
>
> Here, what is the value of these variables.
>
> (gdb) p l
> (gdb) p k
> (gdb) p gsub_gpos->FeatureList.FeatureCount
> (gdb) p otf_langsys->FeatureCount
>
> And, which font is used for the character U+926 (2342)?

--8<---------------cut here---------------start------------->8---
        character: ⍂ (9026, #o21502, #x2342)
preferred charset: unicode (Unicode (ISO10646))
       code point: 0x2342
           syntax: . 	which means: punctuation
      buffer code: #xE2 #x8D #x82
        file code: #xE2 #x8D #x82 (encoded by coding system utf-8)
          display: by this font (glyph code)
    xft:-unknown-DejaVu Sans Mono-normal-normal-normal-*-14-*-*-*-m-0-iso10646-1 (#x810)

Character code properties: customize what to show
  name: APL FUNCTIONAL SYMBOL QUAD BACKSLASH
  general-category: So (Symbol, Other)

There are text properties here:
  fontified            t
--8<---------------cut here---------------end--------------->8---

        The values are show inline.
--8<---------------cut here---------------start------------->8---
(gdb) run
Starting program: /usr/local/git/build/src/emacs 
[Thread debugging using libthread_db enabled]
[New Thread 0x7ff631fdd770 (LWP 25789)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7ff631fdd770 (LWP 25789)]
0x00000000006fbea6 in ftfont_otf_features (gsub_gpos=0x70c2880) at /usr/local/git/emacs/src/ftfont.c:1365
1365                  OTF_TAG_SYM (sym, gsub_gpos->FeatureList.Feature[l].FeatureTag);
(gdb)  p l
$1 = 0
(gdb) p k
$2 = 21329
(gdb) p gsub_gpos->FeatureList.FeatureCount
$3 = 0
(gdb) p otf_langsys->FeatureCount
$4 = 21330
(gdb) p gsub_gpos->FeatureList.Feature[l].FeatureTag
Cannot access memory at address 0x0
(gdb) bt
#0  0x00000000006fbea6 in ftfont_otf_features (gsub_gpos=0x70c2880) at /usr/local/git/emacs/src/ftfont.c:1365
#1  0x00000000006fc169 in ftfont_otf_capability (font=0x5bd94a0) at /usr/local/git/emacs/src/ftfont.c:1395
#2  0x00000000006878f3 in font_match_p (spec=24475892, font=96310436) at /usr/local/git/emacs/src/font.c:2492
#3  0x0000000000509624 in reorder_font_vector (font_group=99124981, font=0x5bd94a0)
    at /usr/local/git/emacs/src/fontset.c:420
#4  0x0000000000509b90 in fontset_find_font (fontset=93593060, c=2350, face=0x5d43f60, id=-1, fallback=0)
    at /usr/local/git/emacs/src/fontset.c:535
#5  0x0000000000509f26 in fontset_font (fontset=90494900, c=2350, face=0x5d43f60, id=-1)
    at /usr/local/git/emacs/src/fontset.c:678
#6  0x000000000050a949 in font_for_char (face=0x5d43f60, c=2350, pos=1346, object=12340913)
    at /usr/local/git/emacs/src/fontset.c:984
#7  0x000000000068b8c5 in font_range (pos=1347, limit=0x7fff3a11da18, w=0x573d4b0, face=0x5d43f60, 
    string=12340913) at /usr/local/git/emacs/src/font.c:3712
#8  0x00000000006effdc in autocmp_chars (cft_element=31766261, charpos=1346, bytepos=1346, limit=1762, 
    win=0x573d4b0, face=0x5d43f60, string=12340913) at /usr/local/git/emacs/src/composite.c:948
#9  0x00000000006f0e64 in composition_reseat_it (cmp_it=0x7fff3a11eb10, charpos=1346, bytepos=1346, 
    endpos=1762, w=0x573d4b0, face=0x5d43f60, string=12340913) at /usr/local/git/emacs/src/composite.c:1112
#10 0x000000000043e499 in next_element_from_buffer (it=0x7fff3a11e590)
    at /usr/local/git/emacs/src/xdisp.c:6496
#11 0x000000000043bbf0 in get_next_display_element (it=0x7fff3a11e590)
    at /usr/local/git/emacs/src/xdisp.c:5655
#12 0x0000000000458388 in display_line (it=0x7fff3a11e590) at /usr/local/git/emacs/src/xdisp.c:16578
#13 0x000000000045098a in try_window (window=91477172, pos={charpos = 1, bytepos = 1}, check_margins=1)
    at /usr/local/git/emacs/src/xdisp.c:14042
#14 0x000000000044f43f in redisplay_window (window=91477172, just_this_one_p=0)
    at /usr/local/git/emacs/src/xdisp.c:13665
#15 0x000000000044ae11 in redisplay_window_0 (window=91477172) at /usr/local/git/emacs/src/xdisp.c:12255
#16 0x000000000066defd in internal_condition_case_1 (bfun=0x44add5 <redisplay_window_0>, arg=91477172, 
    handlers=12699573, hfun=0x44adaa <redisplay_window_error>) at /usr/local/git/emacs/src/eval.c:1559
#17 0x000000000044ad8b in redisplay_windows (window=91477172) at /usr/local/git/emacs/src/xdisp.c:12234
#18 0x000000000044ad5c in redisplay_windows (window=115538948) at /usr/local/git/emacs/src/xdisp.c:12228
#19 0x0000000000449f3e in redisplay_internal (preserve_echo_area=0) at /usr/local/git/emacs/src/xdisp.c:11810
#20 0x0000000000447d40 in redisplay () at /usr/local/git/emacs/src/xdisp.c:11016
#21 0x00000000005d0784 in read_char (commandflag=1, nmaps=4, maps=0x7fff3a120910, prev_event=12340913, 
    used_mouse_menu=0x7fff3a120c44, end_time=0x0) at /usr/local/git/emacs/src/keyboard.c:2649
#22 0x00000000005dd60c in read_key_sequence (keybuf=0x7fff3a120fb0, bufsize=30, prompt=12340913, 
    dont_downcase_last=0, can_return_switch_frame=1, fix_current_buffer=1)
    at /usr/local/git/emacs/src/keyboard.c:9343
#23 0x00000000005cd5bd in command_loop_1 () at /usr/local/git/emacs/src/keyboard.c:1621
#24 0x000000000066dd61 in internal_condition_case (bfun=0x5cd223 <command_loop_1>, handlers=12428177, 
    hfun=0x5ccb8b <cmd_error>) at /usr/local/git/emacs/src/eval.c:1511
#25 0x00000000005ccf42 in command_loop_2 () at /usr/local/git/emacs/src/keyboard.c:1338
#26 0x000000000066d713 in internal_catch (tag=12409473, func=0x5ccf28 <command_loop_2>, arg=12340913)
    at /usr/local/git/emacs/src/eval.c:1247
#27 0x00000000005ccf02 in command_loop () at /usr/local/git/emacs/src/keyboard.c:1317
#28 0x00000000005cc6d1 in recursive_edit_1 () at /usr/local/git/emacs/src/keyboard.c:942
#29 0x00000000005cc874 in Frecursive_edit () at /usr/local/git/emacs/src/keyboard.c:1004
#30 0x00000000005cadfb in main (argc=1, argv=0x7fff3a1218d8) at /usr/local/git/emacs/src/emacs.c:1728
(gdb) q
--8<---------------cut here---------------end--------------->8---


-- 
Being popular is important.  Otherwise people might not like you.
Manoj Srivastava <srivasta@acm.org> <http://www.golden-gryphon.com/>  
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