core dump with prompt_subst and unusual PROMPT [4.3.2,4.2.6,4.2.1]

core dump with prompt_subst and unusual PROMPT [4.3.2,4.2.6,4.2.1]

[Matt Pharr]

If I source the following script (extracted from my .zshrc file), zsh  
dumps core--I've reproduced this on 4.2.1, 4.2.6, and 4.3.2.   
Admittedly it's pretty ugly and possibly malformed, though a core  
dump's a core dump...  A representative stack trace (from 4.3.2) is  
below.

thanks,
-matt

--- snip ---
PROMPT='[${{NKAPPDIR##/home/mmp/sw/}%%nkapp}] %(?..err %B%?%b )%(1v.%B 
%v%b .)%B%#%b '

setopt  autocd                  autolist                 
automenu        \
         autoremoveslash         cdablevars      \
         correct                 correctall               
cshnullglob     \
         extendedglob            numericglobsort \
         ignoreeof               listtypes                
longlistjobs    \
         noclobber               notify                   
pathdirs        \
         promptsubst \
         pushdignoredups         pushdtohome              
rcquotes        \
         completeinword          alwaystoend              
listambiguous   \
         alwayslastprompt
setopt  histignoredups          histignorespace          
appendhistory   \
         extendedhistory         histallowclobber        #histsavenodups
unsetopt bgnice      # bleh!

--- snip ---

[mmp@lux]/tmp% source xxx
zsh: bad substitution
*** glibc detected *** zsh: double free or corruption (!prev):  
0x0863e3b8 ***
======= Backtrace: =========
/lib/libc.so.6[0xd28424]
/lib/libc.so.6(__libc_free+0x77)[0xd2895f]
/usr/local/lib/zsh/4.3.2/zsh/zle.so(reexpandprompt+0x20)[0x40249c38]
/usr/local/lib/zsh/4.3.2/zsh/zle.so(zrefresh+0xbef)[0x40251e33]
/usr/local/lib/zsh/4.3.2/zsh/zle.so(trashzle+0x63)[0x40249d5b]
zsh(zwarn+0xa6)[0x80aafe6]
zsh(zerr+0x43)[0x80ab4c3]
zsh(paramsubst+0x5f7)[0x80a180f]
zsh[0x80a53b9]
zsh(prefork+0x75)[0x80a551d]
zsh(singsub+0x35)[0x80a5dc1]
zsh(promptexpand+0x1b5)[0x809de0d]
/usr/local/lib/zsh/4.3.2/zsh/zle.so(reexpandprompt+0x3b)[0x40249c53]
/usr/local/lib/zsh/4.3.2/zsh/zle.so(zrefresh+0xbef)[0x40251e33]
/usr/local/lib/zsh/4.3.2/zsh/zle.so(zleread+0x386)[0x4024a19e]
zsh(ingetc+0x247)[0x8078ec3]
zsh[0x80724d9]
zsh(gettok+0x1e)[0x807fa96]
zsh(yylex+0x15)[0x8080a5d]
zsh(parse_event+0x29)[0x80976a1]
zsh(loop+0x1b9)[0x8075dc9]
zsh(zsh_main+0x1a8)[0x8078548]
/lib/libc.so.6(__libc_start_main+0xc6)[0xcd9de6]
zsh[0x805297d]
======= Memory map: ========
00101000-00123000 r-xp 00000000 08:02 787232     /lib/libm-2.3.5.so
00123000-00124000 r-xp 00021000 08:02 787232     /lib/libm-2.3.5.so
00124000-00125000 rwxp 00022000 08:02 787232     /lib/libm-2.3.5.so
00333000-0033c000 r-xp 00000000 08:02 787235     /lib/ 
libgcc_s-4.0.0-20050520.so.1
0033c000-0033d000 rwxp 00009000 08:02 787235     /lib/ 
libgcc_s-4.0.0-20050520.so.1
0048b000-004a5000 r-xp 00000000 08:02 786576     /lib/ld-2.3.5.so
004a5000-004a6000 r-xp 00019000 08:02 786576     /lib/ld-2.3.5.so
004a6000-004a7000 rwxp 0001a000 08:02 786576     /lib/ld-2.3.5.so
004a9000-004ac000 r-xp 00000000 08:02 787251     /lib/libtermcap.so. 
2.0.8
004ac000-004ad000 rwxp 00002000 08:02 787251     /lib/libtermcap.so. 
2.0.8
00cc5000-00de9000 r-xp 00000000 08:02 787231     /lib/libc-2.3.5.so
00de9000-00deb000 r-xp 00124000 08:02 787231     /lib/libc-2.3.5.so
00deb000-00ded000 rwxp 00126000 08:02 787231     /lib/libc-2.3.5.so
00ded000-00def000 rwxp 00ded000 00:00 0
00df1000-00df3000 r-xp 00000000 08:02 787233     /lib/libdl-2.3.5.so
00df3000-00df4000 r-xp 00001000 08:02 787233     /lib/libdl-2.3.5.so
00df4000-00df5000 rwxp 00002000 08:02 787233     /lib/libdl-2.3.5.so
074e6000-07524000 r-xp 00000000 08:02 1124284    /usr/lib/ 
libncurses.so.5.4
07524000-0752d000 rwxp 0003d000 08:02 1124284    /usr/lib/ 
libncurses.so.5.4
07dc1000-07dd3000 r-xp 00000000 08:02 787242     /lib/libnsl-2.3.5.so
07dd3000-07dd4000 r-xp 00011000 08:02 787242     /lib/libnsl-2.3.5.so
07dd4000-07dd5000 rwxp 00012000 08:02 787242     /lib/libnsl-2.3.5.so
07dd5000-07dd7000 rwxp 07dd5000 00:00 0
08048000-080b6000 r-xp 00000000 08:02 1125404    /usr/local/bin/zsh
080b6000-080ba000 rwxp 0006d000 08:02 1125404    /usr/local/bin/zsh
080ba000-080d1000 rwxp 080ba000 00:00 0
08623000-08686000 rwxp 08623000 00:00 0          [heap]
40000000-40001000 r-xp 40000000 00:00 0
40001000-40002000 rwxp 40001000 00:00 0
40016000-40018000 rwxp 40016000 00:00 0
40018000-40218000 r-xp 00000000 08:02 1116573    /usr/lib/locale/ 
locale-archive
40218000-4021c000 rwxp 40218000 00:00 0
4021c000-40222000 r-xs 00000000 08:02 1116794    /usr/lib/gconv/gconv- 
modules.cache
40223000-40226000 r-xp 00000000 08:02 556946     /usr/local/lib/zsh/ 
4.3.2/zsh/rlimits.so
40226000-40227000 rwxp 00002000 08:02 556946     /usr/local/lib/zsh/ 
4.3.2/zsh/rlimits.so
4022c000-40235000 r-xp 00000000 08:02 784949     /lib/ 
libnss_files-2.3.5.so
40235000-40236000 r-xp 00008000 08:02 784949     /lib/ 
libnss_files-2.3.5.so
40236000-40237000 rwxp 00009000 08:02 784949     /lib/ 
libnss_files-2.3.5.so
40237000-40262000 r-xp 00000000 08:02 556975     /usr/local/lib/zsh/ 
4.3.2/zsh/zle.so
40262000-40267000 rwxp 0002a000 08:02 556975     /usr/local/lib/zsh/ 
4.3.2/zsh/zle.so
zsh: 28006 abort (core dumped)  zsh02 556957     /usr/local/lib/z

Re: core dump with prompt_subst and unusual PROMPT [4.3.2,4.2.6,4.2.1]

[Peter Stephenson]

Matt Pharr wrote:
> If I source the following script (extracted from my .zshrc file), zsh  
> dumps core--I've reproduced this on 4.2.1, 4.2.6, and 4.3.2.   
> Admittedly it's pretty ugly and possibly malformed, though a core  
> dump's a core dump...  A representative stack trace (from 4.3.2) is  
> below.
> 
> thanks,
> -matt
> 
> --- snip ---
> PROMPT='[${{NKAPPDIR##/home/mmp/sw/}%%nkapp}] %(?..err %B%?%b )%(1v.%B 
> %v%b .)%B%#%b '

Thanks... it's actually just the prompt.  It's trying to warn you that
there's a bad substitution in the prompt (you're on your own there...),
and in order to warn you that it's having trouble with substitutions in
the prompt it needs to ensure that the zle display is in order, and to
do that it reexpands the prompt...  which is quite bad luck at this
point.

Index: Src/Zle/zle_main.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Zle/zle_main.c,v
retrieving revision 1.85
diff -u -r1.85 zle_main.c
--- Src/Zle/zle_main.c	25 Apr 2006 15:00:27 -0000	1.85
+++ Src/Zle/zle_main.c	26 May 2006 22:36:41 -0000
@@ -1509,10 +1509,15 @@
 void
 reexpandprompt(void)
 {
-    free(lpromptbuf);
-    lpromptbuf = promptexpand(raw_lp ? *raw_lp : NULL, 1, NULL, NULL);
-    free(rpromptbuf);
-    rpromptbuf = promptexpand(raw_rp ? *raw_rp : NULL, 1, NULL, NULL);
+    static reexpanding;
+
+    if (!reexpanding++) {
+	free(lpromptbuf);
+	lpromptbuf = promptexpand(raw_lp ? *raw_lp : NULL, 1, NULL, NULL);
+	free(rpromptbuf);
+	rpromptbuf = promptexpand(raw_rp ? *raw_rp : NULL, 1, NULL, NULL);
+    }
+    reexpanding--;
 }
 
 /**/

-- 
Peter Stephenson <p.w.stephenson@ntlworld.com>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/