From: "Bart Schaefer" <schaefer@candle.brasslantern.com>
To: "Deborah Ariel Pickett" <debbiep@mail.csse.monash.edu.au>,
zsh-workers@sunsite.dk
Subject: PATCH: 3.1.9-dev-8: Re: Word splitting in zsh
Date: Sat, 10 Feb 2001 20:24:11 +0000 [thread overview]
Message-ID: <1010210202412.ZM20301@candle.brasslantern.com> (raw)
In-Reply-To: <000d01c0926a$ce26c590$21c9ca95@mow.siemens.ru>
In-Reply-To: <1010209181818.ZM16052@candle.brasslantern.com>
On Feb 9, 10:34am, Andrej Borsenkow wrote:
}
} > zagzig% echo $ZSH_VERSION
} > 3.0.8
} > zagzig% setopt shwordsplit
} > zagzig% print -l ${1+"$@"}
} > a1
} > a2
} > a3
} > b
} > c
} > zagzig%
} >
}
} > Well, that's not quite right,
}
} It is simply wrong.
}
} but 3.1.9-dev-8 is even worse:
} >
} > zagzig% echo $ZSH_VERSION
} > 3.1.9-dev-8
} > zagzig% set "a1 a2 a3" b c
} > zagzig% print -l ${1+"$@"}
} > a1 a2 a3 b c <-- Yipes!
}
} Well, this is "correct" *zsh* behaviour. The part after `+' is a word -
} not array. And is taken as single word and is never splitted.
On Feb 9, 6:18pm, Bart Schaefer wrote:
}
} Yes, your analysis is correct; the bug is that there should not be a scalar
} context there. The effect of ${NAME:+WORD} and ${NAME:-WORD} should be to
} replace the context of NAME with the context of WORD in the event that NAME
} is (or not) set. Put another way, the type of NAME should only determine
} the type of the whole ${...} when NAME really is being substituted.
This turned out to be remarkably easy; patch and explanation below.
On Feb 9, 10:34am, Andrej Borsenkow wrote:
}
} That is just because of above. The structure of WORD in ${name+WORD} is not
} remebered. But note the same bug again:
}
} bor@itsrm2% set 'a b c' 1 2
} bor@itsrm2% IFS=: print -l ${1+"$@"}
} a b c 1 2
} bor@itsrm2% setopt shwordsplit
} bor@itsrm2% IFS=: print -l ${1+"$@"}
} a
} b
} c
} 1
} 2
}
} IFS value is silently ignored.
This is actually something entirely different, and is not really a bug at
all. The problem with Andrej's example is that ${1+"$@"} is expanded
before the assignment to IFS takes place. If you replace the `print's
above with
args() { print -l $* ++ ${1+"$@"} }
IFS=: args "$@"
then you'll see that IFS is handled correctly (modulo the other bug).
OK, here's the patch; I won't commit this until I get some feedback on it.
The solution is simply (1) pass &aval into multsub() so that it returns
an array when the word being expanded would expand to an array; (2) pass
the current value of `spbreak' through multsub() in case of ${=...}; (3)
turn off word splitting after multsub() returns, because multsub() will
have already performed quoting and splitting as appropriate.
This applies only to ${...+...} and ${...-...}, with or without the `:'.
As I mentioned, there would be some benefit to also doing this for the
${...=...} forms, because then things like ${(A)foo="$bar[@]"} would work
independently of the setting of shwordplit.
There's some question in my mind of whether ${~...} and ${^...} should be
treated this way, too; e.g. (this is what does NOT happen):
zsh% print -l ${^1+"x$@x"}
xa1:a2 a3x
xbx
xcx
That `^' and `~' are not propagated now could even be an argument for not
propagating `=' either, but that would cause a larger change in behavior
in the instances where the right-hand-side of the `+'/`-' is not quoted
(and the shwordsplit option is not set).
I've also left unchanged the behavior of ${(s( ))...}, ${(z)...}, etc.,
because those constructs aren't possible in Bourne shell and in general
the expansion flags take precedence over everything else -- and because
there's a lot more potential for breakage when messing with those.
Index: Src/subst.c
===================================================================
--- Src/subst.c 2001/01/16 17:18:12 1.72
+++ Src/subst.c 2001/02/10 18:31:20
@@ -749,7 +749,9 @@
int chkset = 0;
int vunset = 0;
int wantt = 0;
- int spbreak = isset(SHWORDSPLIT) && !ssub && !qt;
+ static int mult_spbreak, mult_shwsplit;
+ int spbreak = (!ssub && !qt &&
+ (mult_spbreak? mult_shwsplit : isset(SHWORDSPLIT)));
char *val = NULL, **aval = NULL;
unsigned int fwidth = 0;
struct value vbuf;
@@ -1378,8 +1380,14 @@
/* Fall Through! */
case '-':
if (vunset) {
+ int shws = mult_shwsplit, spbr = mult_spbreak;
+ mult_shwsplit = spbreak;
+ mult_spbreak = 1;
val = dupstring(s);
- multsub(&val, NULL, &isarr, NULL);
+ multsub(&val, (aspar ? NULL : &aval), &isarr, NULL);
+ mult_shwsplit = shws;
+ mult_spbreak = spbr;
+ spbreak = 0;
copied = 1;
}
break;
--
Bart Schaefer Brass Lantern Enterprises
http://www.well.com/user/barts http://www.brasslantern.com
Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net
next prev parent reply other threads:[~2001-02-10 20:24 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <000d01c0926a$ce26c590$21c9ca95@mow.siemens.ru>
2001-02-09 18:18 ` Bart Schaefer
2001-02-10 20:24 ` Bart Schaefer [this message]
2001-02-12 7:38 ` PATCH: 3.1.9-dev-8: " Andrej Borsenkow
2001-02-12 14:12 ` Andrej Borsenkow
2001-02-12 19:38 ` Bart Schaefer
2001-02-13 7:51 ` More incompatibility :-) " Andrej Borsenkow
2001-02-13 9:26 ` Bart Schaefer
2001-02-13 9:57 ` Andrej Borsenkow
2001-02-13 19:33 ` Bart Schaefer
2001-02-14 18:00 ` Peter Stephenson
2001-02-15 6:17 ` Andrej Borsenkow
2001-02-15 8:34 ` Bart Schaefer
2001-02-15 10:35 ` More incompatibility (word splitting) Peter Stephenson
2001-02-16 7:43 ` PATCH: " Bart Schaefer
2001-02-16 8:50 ` Andrej Borsenkow
2001-02-16 17:03 ` Bart Schaefer
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