GNU bug report logs - #63711
30.0.50; Crash in xdisp.c when it->string is 0x0

Previous Next

Full log

View this message in rfc822 format

From: Thomas Fitzsimmons <fitzsim <at> fitzsim.org>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: 63711 <at> debbugs.gnu.org
Subject: bug#63711: 30.0.50; Crash in xdisp.c when it->string is 0x0
Date: Thu, 25 May 2023 13:43:03 -0400

Eli Zaretskii <eliz <at> gnu.org> writes:

>> From: Thomas Fitzsimmons <fitzsim <at> fitzsim.org>
>> Cc: 63711 <at> debbugs.gnu.org
>> Date: Thu, 25 May 2023 11:25:23 -0400
>> 
>> >   (gdb) prow
>> 
>> y=701 x=0 pwid=1287 a+d=18+5=23 phys=16+4=20 vis=23
>> used=(LMargin=0,Text=113,RMargin=0) Hash=258184180
>> start=0 end=0 ENA MODEL
>> 
>> >   (gdb) pgrow
>> 
>> TEXT: 113 glyphs
>>   0    0: CHAR[ ] str=0xf188ab16[0] blev=0,btyp=L w=11 a+d=18+5 face=1
>>   1   11: CHAR[U] str=0x1ccec60[1] blev=0,btyp=L w=11 a+d=18+5 face=1
>>   2   22: CHAR[:] str=0x4e125d0[0] blev=0,btyp=L w=11 a+d=18+5 face=1
>>   3   33: STRETCH[23+18] str=0x1ccecb8[0] w=33 a+d=18+5 face=1
>>   4   66: CHAR[@] str=0x1ccecb8[0] blev=0,btyp=L w=11 a+d=18+5 face=1
>
> This is the mode line: first sign of trouble.  We are handling a
> mode-line glyph row as if it were a text row.  That cannot lead to
> anything good, ever.
>
>> >   (gdb) p first_reusable_row - start_row
>> 
>> $22 = 15
>> 
>> >   (gdb) p first_row_to_display - start_row
>> 
>> $23 = 30
>
> So we think that the first glyph row to display is screen line 30
> (zero-based).  Is it true that the window was supposed to have only 30
> lines in its body, not 31?

I don't remember, but it does sound plausible that the window displaying
the "js.el" buffer was ~30 lines tall.  I was probably working in a
"split-window-below" scenario.  I don't know whether it was supposed to
be 30 or 31; maybe there some consistency check I could perform in the
GDB session to nail down the expected value?

Thanks,
Thomas

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.