Re: segfault in 4.1.1-test-2 [now with a different param expansion]

[Anthony Heading <aheading@jpmorgan.com>]

On Wed, May 21, 2003 at 05:03:39PM +0100, Peter Stephenson wrote:
> I *hate* that function.

Heh. For me, even the manual page is more than enough.  So thanks!

Since the iron is hot, however...  see below  :-)

I'm probably missing something obvious here - At the point of the fault,
parameter 'a' of nstrpcmp is null, however it looks to me like it's
outside the range of the qsort??!  Maybe I don't believe the
debugger. Anyhow, both gcc 3.3 and Sun C v5 show the same behaviour,
but I couldn't reproduce the fault on Linux.  Also, though
the implications seem a bit odd, overriding qsort using
LD_PRELOAD seems to avoid the crash.

Again, let me know if I should to do more investigation.

Regards

Anthony


========================================================

fires-02% gdb Src/zsh
GNU gdb 5.3
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GDB is free software, covered by the GNU General Public License, and you are
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Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "sparc-sun-solaris2.8"...
(gdb) run
Starting program: /tmp/zsh-4.1.1-test-2/Src/zsh 
fires-02% cd /tmp
fires-02% cat numbers
22829
29156
15632
19174
4296
10392
5297
6392
19035
24181
2494
20468
20513
14808
26229
fires-02% x=($(<numbers))
fires-02% echo ${(no)x}

Program received signal SIGSEGV, Segmentation fault.
0xff15c1b0 in __strcoll_std () from /usr/lib/libc.so.1
(gdb) where
#0  0xff15c1b0 in __strcoll_std () from /usr/lib/libc.so.1
#1  0x000a86b4 in nstrpcmp (a=0xff1e01dc, b=0xff1e01ec) at subst.c:550
#2  0xff14b07c in qsort () from /usr/lib/libc.so.1
#3  0x000af434 in paramsubst (l=0xff1e01a8, n=0xff1e01bc, str=0xffbed71c, qt=0, ssub=0) at subst.c:1991
#4  0x000a69b4 in stringsubst (list=0xff1e01a8, node=0xff1e01bc, ssub=0, asssub=0) at subst.c:137
#5  0x000a61d0 in prefork (list=0xff1e01a8, flags=1) at subst.c:74
#6  0x000331dc in execcmd (state=0xffbedc48, input=0, output=0, how=18, last1=2) at exec.c:1796
#7  0x00030cb0 in execpline2 (state=0xffbedc48, pcode=323, how=18, input=0, output=0, last1=0) at exec.c:1228
#8  0x0002fa78 in execpline (state=0xffbedc48, slcode=4098, how=18, last1=0) at exec.c:1018
#9  0x0002eec0 in execlist (state=0xffbedc48, dont_change_job=0, exiting=0) at exec.c:829
#10 0x0002e9d8 in execode (p=0xff1e0150, dont_change_job=0, exiting=0) at exec.c:730
#11 0x000545d4 in loop (toplevel=1, justonce=0) at init.c:167
#12 0x000587b4 in zsh_main (argc=1, argv=0xffbede54) at init.c:1239
#13 0x0001273c in main (argc=1, argv=0xffbede54) at main.c:37
(gdb) frame 3
#3  0x000af4d4 in paramsubst (l=0xff1e05a8, n=0xff1e05bc, str=0xffbed71c, qt=0, ssub=0) at subst.c:1998
1998                        qsort(aval, i, sizeof(char *), sortfn[sortit-1]);
(gdb) print aval
$32 = (char **) 0xff1e05e0
(gdb) print i
$33 = 15
(gdb) 


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