From: Oliver Kiddle <okiddle@yahoo.co.uk>
To: Zsh workers <zsh-workers@sunsite.dk>
Subject: PATCH: tied parameters bug
Date: Tue, 08 Oct 2002 11:01:40 +0100 [thread overview]
Message-ID: <E17yrBM-0006c5-00@bimbo.logica.co.uk> (raw)
I noticed this bug while looking at aspects of the parameter code:
% g() {
> local SC="hello"
> unset sc
> }
% typeset -T SC sc
% g
Tied parameters use pm->ename to store the name of the parameter they
are tied to in string form. So in this code, it unsets the local
instead of the global SC. As a result, the global SC still exists and
if used, fairly shortly results in a seg fault. The same problem
applies the other way around (unsetting the scalar with a local array).
The fix below relies on the tied parameters being at the same local
level (which I believe always holds true). It makes the code search for
the parameter at the correct local level and then unsets it which
requires a nasty hack to avoid the parameter node being removed from
the table.
Oliver
Index: Src/params.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/params.c,v
retrieving revision 1.65
diff -u -r1.65 params.c
--- Src/params.c 5 Aug 2002 12:36:00 -0000 1.65
+++ Src/params.c 8 Oct 2002 09:26:44 -0000
@@ -2234,8 +2234,21 @@
/* remove it under its alternate name if necessary */
if (pm->ename && !altflag) {
altpm = (Param) paramtab->getnode(paramtab, pm->ename);
- if (altpm)
+ /* tied parameters are at the same local level as each other */
+ oldpm = NULL;
+ while (altpm && altpm->level > pm->level) {
+ /* param under alternate name hidden by a local */
+ oldpm = altpm;
+ altpm = altpm->old;
+ }
+ if (altpm) {
+ if (oldpm) {
+ oldpm->old = altpm->old;
+ /* fudge things so removenode isn't called */
+ altpm->level = locallevel;
+ }
unsetparam_pm(altpm, 1, exp);
+ }
}
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next reply other threads:[~2002-10-08 10:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-10-08 10:01 Oliver Kiddle [this message]
2002-10-09 8:47 ` Oliver Kiddle
2002-10-09 9:38 ` Peter Stephenson
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