Re: [Pkg-zsh-devel] Bug#793168: zsh: expand-substitution-on-TAB broke for $(()) in 5.0.8 [origin: adi@hexapodia.org]

[Peter Stephenson <p.w.stephenson@ntlworld.com>]

On Sat, 25 Jul 2015 20:15:09 +0100
Peter Stephenson <p.w.stephenson@ntlworld.com> wrote:
> On Sat, 25 Jul 2015 19:03:41 +0200
> Axel Beckert <abe@deuxchevaux.org> wrote:
> > with zsh 5.0.7 and earlier versions, if I type $((5*8)) and then hit TAB,
> > the expression is replaced with its evaluation ("40" in this case). The
> > same feature works with many different substitutions.
> > 
> > as of 5.0.8 TAB-substituting does not work with $(()) anymore.
> > 
> > It does still work right with "${VAR}" and "$[5+8]".
> I think the patch below fixes the expand-or-complete case.
> 
> The _expand case is in shell code.  The difference apparently
> comes from the fact that in the new code $(( ... )) gets
> tokenised such that the outer parentheses become Inparmath
> and Outparmath, while the inner parentheses don't get tokenised.

This fixes the standard quoting code, which is used by completion in a
slightly non-standard (surprised?) way, with tokens still present
in the string, so we can detect the math expression and avoid quoting it
further.  _expand now works.

This is evidently not how $[...] gets handled, but as we have syntactic
markers in the present case we might as well make use of them.

pws

diff --git a/Src/utils.c b/Src/utils.c
index 0acab88..f7aaaed 100644
--- a/Src/utils.c
+++ b/Src/utils.c
@@ -5551,7 +5551,25 @@ quotestring(const char *s, char **e, int instring)
 		/* Needs to be passed straight through. */
 		if (dobackslash)
 		    *v++ = '\\';
-		*v++ = *u++;
+		if (*u == Inparmath) {
+		    /*
+		     * Already syntactically quoted: don't
+		     * add more.
+		     */
+		    int inmath = 1;
+		    *v++ = *u++;
+		    for (;;) {
+			char uc = *u;
+			*v++ = *u++;
+			if (uc == '\0')
+			    break;
+			else if (uc == Outparmath && !--inmath)
+			    break;
+			else if (uc == Inparmath)
+			    ++inmath;
+		    }
+		} else
+		    *v++ = *u++;
 		continue;
 	    }