Re: bin/50827: sh -c ': "${x=$((1))}"' gives bogus syntax error

[Robert Elz <kre%munnari.OZ.AU@localhost>]

The following reply was made to PR bin/50827; it has been noted by GNATS.

From: Robert Elz <kre%munnari.OZ.AU@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: bin/50827: sh -c ': "${x=$((1))}"' gives bogus syntax error
Date: Fri, 19 Feb 2016 16:31:13 +0700

     Date:        Thu, 18 Feb 2016 07:35:00 +0000 (UTC)
     From:        rhansen%rhansen.org@localhost
     Message-ID:  <20160218073500.BFF977ACD0%mollari.NetBSD.org@localhost>
 
   | /bin/sh incorrectly reports a syntax error ("Missing '}'") with the following line:
   | 
   |     : "${x=$((1))}"
 
 It also mishandles ...
 
 sh -c ': ${x="$(("1"))"}'
 sh: Syntax error: Missing '))'
 
 and similar cases.
 
 I believe the following patch might fix both of those problems (the 4
 lines deleted fix rhansen's problem, the extra manipulation of varnest
 and associated code fixes the $(( )) case.)
 
 These bugs have been there a long time, so once verified, the fix should
 be pulled up to the netbsd 6 & netbsd 7 series (all variants.)
 
 kre
 
 --- parser.c.old	2014-08-30 06:38:31.000000000 +0700
 +++ parser.c	2016-02-19 16:18:50.000000000 +0700
 @@ -1106,13 +1106,11 @@
  					--parenlevel;
  				} else {
  					if (pgetc() == ')') {
 +						if (varnest > 0)  /*always*/
 +							varnest--;
  						if (--arinest == 0) {
  							USTPUTC(CTLENDARI, out);
  							syntax = prevsyntax;
 -							if (syntax == DQSYNTAX)
 -								SETDBLQUOTE();
 -							else
 -								CLRDBLQUOTE();
  						} else
  							USTPUTC(')', out);
  					} else {
 @@ -1562,6 +1560,13 @@
  		 */
  		USTPUTC('(', out);
  	}
 +
 +	varnest++;
 +	if (varnest >= maxnest) {
 +		dblquotep = ckrealloc(dblquotep, maxnest / 8);
 +		dblquotep[(maxnest / 32) - 1] = 0;
 +		maxnest += 32;
 +	}
  	goto parsearith_return;
  }