zsh/pcre module causes core dump w/cvs co as of 2007-04-02

[Bart Schaefer <schaefer@brasslantern.com>]

As it happens, I inadvertently compiled with --enable-pcre on a system
that had the libraries but not the header files for PCRE.  Obviously
this is pilot error, but it shouldn't lead to a crash.

schaefer<500> [[ ab -pcre-match xy ]]
zsh: unrecognized condition: `ab'
schaefer<501> zmodload zsh/pcre
schaefer<502> [[ ab -pcre-match xy ]]

Program received signal SIGSEGV, Segmentation fault.
0x080ac50b in pattryrefs (prog=0x8552c40, string=0x1 "", stringlen=-1, 
    unmetalen=-1, patoffset=0, nump=0x0, begp=0x0, endp=0x0)
    at ../../zsh-4.0/Src/pattern.c:1781
1781        if (*string == Nularg) {
(gdb) where
#0  0x080ac50b in pattryrefs (prog=0x8552c40, string=0x1 "", stringlen=-1, 
    unmetalen=-1, patoffset=0, nump=0x0, begp=0x0, endp=0x0)
    at ../../zsh-4.0/Src/pattern.c:1781
#1  0x080ac4a9 in pattry (prog=0x8552c40, string=0x1 "")
    at ../../zsh-4.0/Src/pattern.c:1725
#2  0x080742b3 in matchpat (a=0x1 "", b=0xb7d612d8 "ab")
    at ../../zsh-4.0/Src/glob.c:1992
#3  0x0806569c in cond_match (args=0xb7d612c8, num=0, str=0x1 "")
    at ../../zsh-4.0/Src/cond.c:479
#4  0x0806448a in evalcond (state=0xbfe9cc90, fromtest=0x0)
    at ../../zsh-4.0/Src/cond.c:122
#5  0x0806dcae in execcond (state=0xbfe9cc90, do_exec=0)
    at ../../zsh-4.0/Src/exec.c:3499
#6  0x08066fdb in execsimple (state=0xbfe9cc90) at ../../zsh-4.0/Src/exec.c:827
#7  0x080671c2 in execlist (state=0xbfe9cc90, dont_change_job=0, exiting=0)
    at ../../zsh-4.0/Src/exec.c:915
#8  0x08066eb5 in execode (p=0xb7d61268, dont_change_job=0, exiting=0)
    at ../../zsh-4.0/Src/exec.c:793
#9  0x0807e86e in loop (toplevel=1, justonce=0) at ../../zsh-4.0/Src/init.c:180
#10 0x0808116c in zsh_main (argc=1, argv=0xbfe9cdd4)
    at ../../zsh-4.0/Src/init.c:1347
#11 0x08052e76 in main (argc=1, argv=0xbfe9cdd4) at ../../zsh-4.0/Src/main.c:93