Bug in ${(Q)...}

Bug in ${(Q)...}

[Philippe Troin]

% emulate -R zsh
% setopt extended_glob
% echo $ZSH_VERSION "<${(Q)${$(print hello)/%hello#}}>"
4.0.6 < >

Shouldn't that be:
4.0.6 <>

(no space)

But note that:

% echo $ZSH_VERSION "<${(Q)$(print hello)/%hello#}>"  
4.0.6 <>

And that sounds good.

Phil.

Re: Bug in ${(Q)...}

[Bart Schaefer]

On Jul 12,  7:38pm, Philippe Troin wrote:
} Subject: Bug in ${(Q)...}
}
} % setopt extended_glob
} % echo $ZSH_VERSION "<${(Q)${$(print hello)/%hello#}}>"
} 4.0.6 < >
} 
} Shouldn't that be:
} 4.0.6 <>
} 
} (no space)

This is indeed a bug.  No process substitution required:

schaefer<501> x=(hello)
schaefer<502> setopt extendedglob
schaefer<503> echo $ZSH_VERSION "<${(Q)${${x}/%hello#}}>"
4.1.1-dev-1 < >

But it's not arrays, either, which I initially thought it was:

schaefer<505> x=hello
schaefer<506> echo $ZSH_VERSION "<${(Q)${${x}/%hello#}}>"
4.1.1-dev-1 < >
schaefer<507> echo $ZSH_VERSION "<${(Q)${x/%hello#}}>" 
4.1.1-dev-1 < >

So I'm not sure if this is really a problem with (Q) in paramsubst(), or
if it's deeper, in parse_subst_string(), and it just happens that (Q)
makes it visible.

Re: Bug in ${(Q)...}

[Peter Stephenson]

Bart Schaefer wrote:
> On Jul 12,  7:38pm, Philippe Troin wrote:
> } Subject: Bug in ${(Q)...}
> }
> } % setopt extended_glob
> } % echo $ZSH_VERSION "<${(Q)${$(print hello)/%hello#}}>"
> } 4.0.6 < >
> }
> } Shouldn't that be:
> } 4.0.6 <>
> }
> } (no space)
>
> So I'm not sure if this is really a problem with (Q) in paramsubst(), or
> if it's deeper, in parse_subst_string(), and it just happens that (Q)
> makes it visible.

I think the fix is the following.  I've never quite followed the logic
of using a string consisting only of a Nularg to represent an empty
string, but it occurs sporadically.

Index: Src/lex.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/lex.c,v
retrieving revision 1.24
diff -u -r1.24 lex.c
--- Src/lex.c	6 Oct 2002 18:38:14 -0000	1.24
+++ Src/lex.c	17 Jul 2003 09:29:06 -0000
@@ -1512,7 +1512,7 @@
 {
     int c, l = strlen(s), err, olen;
 
-    if (! *s)
+    if (!*s || !strcmp(s, nulstring))
 	return 0;
     lexsave();
     untokenize(s);

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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