Re: \## -> x when completing

[Bart Schaefer <schaefer@brasslantern.com>]

This gets a bit stream-of-consciousness but maybe that's helpful.

On Feb 8, 11:37pm, Mikael Magnusson wrote:
} Subject: \## -> x when completing
}
} zsh -f
} touch xenon
} autoload compinit; compinit
} setopt globcomplete
} cat \##<tab> -> cat xenon

Hmm.  This is probably happening because the completion internals use
an "x" as a place-holder in some instances.  See the functions
comptils.c:comp_quote, compcore.c:tildequote, and zle_tricky.c:addx,
the latter of which has a big comment explaining what's going on.

However, I think it's more likely compcore.c:set_comp_sep that is the
culprit.  We can find out by changing the 'x' to something else in one
of addx or set_comp_sep and then trying the completion again.

Which reveals that it's neither of those; rather compcore.c:addmatches
is playing funny with us, at line 2302:

2293         if (comppatmatch && *comppatmatch) {
2294             int is = (*comppatmatch == '*');
2295             char *tmp = (char *) zhalloc(2 + llpl + llsl + gfl);
2296 
2297             if (gfl) {
2298                 strcpy(tmp, globflag);
2299                 strcat(tmp, lpre);
2300             } else
2301                 strcpy(tmp, lpre);
2302             tmp[llpl + gfl] = 'x';
2303             strcpy(tmp + llpl + gfl + is, lsuf);
2304 
2305             tokenize(tmp);
2306             remnulargs(tmp);
2307             if (haswilds(tmp)) {
2308                 if (is)
2309                     tmp[llpl + gfl] = Star;
2310                 if ((cp = patcompile(tmp, 0, NULL)))
2311                     haspattern = 1;
2312             }
2313         }

The problem seems to be that remnulargs() has shortened tmp so that
the count (llpl + gfl) is no longer correct.  I believe we can fix
that by moving remnulargs to after line 2309.

Index: Src/Zle/compcore.c
===================================================================
--- Src/Zle/compcore.c	20 Dec 2011 17:13:38 -0000	1.29
+++ Src/Zle/compcore.c	9 Feb 2012 15:33:44 -0000
@@ -2303,10 +2303,10 @@
 		strcpy(tmp + llpl + gfl + is, lsuf);
 
 		tokenize(tmp);
-		remnulargs(tmp);
 		if (haswilds(tmp)) {
 		    if (is)
 			tmp[llpl + gfl] = Star;
+		    remnulargs(tmp);
 		    if ((cp = patcompile(tmp, 0, NULL)))
 			haspattern = 1;
 		}