Re: loving zsh, crashing zsh...

[Peter Stephenson <p.w.stephenson@xxxxxxxxxxxx>]

On Thu, 13 Aug 2009 12:41:21 +0200
Francisco Borges <francisco.borges@xxxxxxxxx> wrote:
> I was annoyed by the evaluation of an if in a script, went to play
> with it in the command line, and found this cute segfault.

(Bugs should go to zsh-workers, not zsh-users, unless you want to point
out a workaround people can use, or something like that.)

> Â~ % if [[ -e /etc ]] { echo "\nNow I'll go back to the '/etc' in the
> if,\nDelete the c in it, hit TAB for completion.\nThis will crash the
> shell\n\n" }
> 
> Now I'll go back to the '/etc' in the if,
> Delete the c in it, hit TAB for completion.
> This will crash the shell
>...
> Some years ago I had found another way to crash Zsh and upon posting
> it, someone answered back by saying something like "you're not
> supposed to do that". Yeah right. Just watch me :-P

There's nothing to stop you doing that, and it should even work, but the
special zsh syntax for tests and loops is a bit tricky to handle.

Index: Src/Zle/zle_tricky.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Zle/zle_tricky.c,v
retrieving revision 1.99
diff -u -r1.99 zle_tricky.c
--- Src/Zle/zle_tricky.c	20 Feb 2009 21:49:58 -0000	1.99
+++ Src/Zle/zle_tricky.c	15 Aug 2009 16:25:16 -0000
@@ -1211,7 +1211,15 @@
 	    (ins == 2 && i == 2) || (ins == 3 && i == 3) ||
 	    tok == BAR    || tok == AMPER     ||
 	    tok == BARAMP || tok == AMPERBANG ||
-	    ((tok == DBAR || tok == DAMPER) && !incond)) {
+	    ((tok == DBAR || tok == DAMPER) && !incond) ||
+	    /*
+	     * Special case: we might reach a new command (incmdpos set)
+	     * if we've already found the string we're completing (tt set)
+	     * without hitting one of the above if we're using one of
+	     * the special zsh forms of delimiting for conditions and
+	     * loops that I really loathe having to support.
+	     */
+	    (tt && incmdpos)) {
 	    /* This is one of the things that separate commands.  If we  *
 	     * already have the things we need (e.g. the token strings), *
 	     * leave the loop.                                           */

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