Re: bin/50179: sh(1) variable expansion bug

[Timo Buhrmester <fstd.lkml%gmail.com@localhost>]

The following reply was made to PR bin/50179; it has been noted by GNATS.

From: Timo Buhrmester <fstd.lkml%gmail.com@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: bin/50179: sh(1) variable expansion bug
Date: Thu, 27 Aug 2015 03:19:02 +0200

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 > >Fix:
 > 	None known so far.
 Okay, FreeBSD fixed this in 2010, see https://lists.freebsd.org/pipermail/svn-src-head/2010-October/021986.html
 
 Attached is the same patch, processed to apply cleanly against our sh(1).
 It Fixes The Problem(TM) for me, on a first glance.  Have not yet run any atf-tests, though.
 
 Timo Buhrmester
 
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 --- bin/sh/expand.c.orig
 +++ bin/sh/expand.c
 @@ -98,7 +98,7 @@ struct arglist exparg;		/* holds expanded arg list */
  STATIC void argstr(char *, int);
  STATIC char *exptilde(char *, int);
  STATIC void expbackq(union node *, int, int);
 -STATIC int subevalvar(char *, char *, int, int, int, int);
 +STATIC int subevalvar(char *, char *, int, int, int, int, int);
  STATIC char *evalvar(char *, int);
  STATIC int varisset(char *, int);
  STATIC void varvalue(char *, int, int, int);
 @@ -495,7 +495,7 @@ expbackq(union node *cmd, int quoted, int flag)
  
  
  STATIC int
 -subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags)
 +subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags, int quotes)
  {
  	char *startp;
  	char *loc = NULL;
 @@ -548,10 +548,10 @@ subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varfla
  		for (loc = startp; loc < str; loc++) {
  			c = *loc;
  			*loc = '\0';
 -			if (patmatch(str, startp, varflags & VSQUOTE))
 +			if (patmatch(str, startp, quotes))
  				goto recordleft;
  			*loc = c;
 -			if ((varflags & VSQUOTE) && *loc == CTLESC)
 +			if (quotes && *loc == CTLESC)
  			        loc++;
  		}
  		return 0;
 @@ -560,11 +560,11 @@ subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varfla
  		for (loc = str - 1; loc >= startp;) {
  			c = *loc;
  			*loc = '\0';
 -			if (patmatch(str, startp, varflags & VSQUOTE))
 +			if (patmatch(str, startp, quotes))
  				goto recordleft;
  			*loc = c;
  			loc--;
 -			if ((varflags & VSQUOTE) && loc > startp &&
 +			if (quotes && loc > startp &&
  			    *(loc - 1) == CTLESC) {
  				for (q = startp; q < loc; q++)
  					if (*q == CTLESC)
 @@ -577,10 +577,10 @@ subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varfla
  
  	case VSTRIMRIGHT:
  	        for (loc = str - 1; loc >= startp;) {
 -			if (patmatch(str, loc, varflags & VSQUOTE))
 +			if (patmatch(str, loc, quotes))
  				goto recordright;
  			loc--;
 -			if ((varflags & VSQUOTE) && loc > startp &&
 +			if (quotes && loc > startp &&
  			    *(loc - 1) == CTLESC) { 
  				for (q = startp; q < loc; q++)
  					if (*q == CTLESC)
 @@ -593,9 +593,9 @@ subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varfla
  
  	case VSTRIMRIGHTMAX:
  		for (loc = startp; loc < str - 1; loc++) {
 -			if (patmatch(str, loc, varflags & VSQUOTE))
 +			if (patmatch(str, loc, quotes))
  				goto recordright;
 -			if ((varflags & VSQUOTE) && *loc == CTLESC)
 +			if (quotes && *loc == CTLESC)
  			        loc++;
  		}
  		return 0;
 @@ -763,7 +763,7 @@ again: /* jump here after setting a variable with ${var=text} */
  		STPUTC('\0', expdest);
  		patloc = expdest - stackblock();
  		if (subevalvar(p, NULL, patloc, subtype,
 -			       startloc, varflags) == 0) {
 +			       startloc, varflags, quotes) == 0) {
  			int amount = (expdest - stackblock() - patloc) + 1;
  			STADJUST(-amount, expdest);
  		}
 @@ -776,7 +776,7 @@ again: /* jump here after setting a variable with ${var=text} */
  	case VSQUESTION:
  		if (set)
  			break;
 -		if (subevalvar(p, var, 0, subtype, startloc, varflags)) {
 +		if (subevalvar(p, var, 0, subtype, startloc, varflags, quotes)) {
  			varflags &= ~VSNUL;
  			/* 
  			 * Remove any recorded regions beyond 
 
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