PATCH: Re: zsh 4.2.5 segfaults when substituting on $match

[Peter Stephenson <pws@xxxxxxxxxxxxxxxxxxxxxxxx>]

DervishD wrote:
>     Hi all :)
> 
>     zsh segfaults with this:
> 
>     $ zsh -f
>     $ emulate -L zsh
>     $ setopt extendedglob
>     $ file="a"
>     $ print ${file//(#b)(*)/${match//a/}}

[I've been away for a couple of days.  For future reference, I am away
again the second half of next week.]

Yes, this looks like being a result of one of the zillions of places
where the code, instead of passing an argument like real programmes do,
declares a global or static variable and vaguely hopes it will come out
right in the end.  This one's been around for a long time; it may even
be my fault.

To other zsh programmers: *Please* don't.

Index: Src/glob.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/glob.c,v
retrieving revision 1.44
diff -u -r1.44 glob.c
--- Src/glob.c	15 Aug 2005 16:04:32 -0000	1.44
+++ Src/glob.c	17 Aug 2005 23:32:56 -0000
@@ -2000,15 +2000,6 @@
 };
 typedef struct repldata *Repldata;
 
-/*
- * List of bits of matches to concatenate with replacement string.
- * The data is a struct repldata.  It is not used in cases like
- * ${...//#foo/bar} even though SUB_GLOBAL is set, since the match
- * is anchored.  It goes on the heap.
- */
-
-static LinkList repllist;
-
 /* Having found a match in getmatch, decide what part of string
  * to return.  The matched part starts b characters into string s
  * and finishes e characters in: 0 <= b <= e <= strlen(s)
@@ -2020,7 +2011,8 @@
 
 /**/
 static char *
-get_match_ret(char *s, int b, int e, int fl, char *replstr)
+get_match_ret(char *s, int b, int e, int fl, char *replstr,
+	      LinkList repllist)
 {
     char buf[80], *r, *p, *rr;
     int ll = 0, l = strlen(s), bl = 0, t = 0, i;
@@ -2230,8 +2222,13 @@
      * lengths.
      */
     int ioff, l = strlen(*sp), uml = ztrlen(*sp), matched = 1, umlen;
-
-    repllist = NULL;
+    /*
+     * List of bits of matches to concatenate with replacement string.
+     * The data is a struct repldata.  It is not used in cases like
+     * ${...//#foo/bar} even though SUB_GLOBAL is set, since the match
+     * is anchored.  It goes on the heap.
+     */
+    static LinkList repllist = NULL;
 
     /* perform must-match test for complex closures */
     if (p->mustoff)
@@ -2254,7 +2251,7 @@
 
     if (fl & SUB_ALL) {
 	int i = matched && pattry(p, s);
-	*sp = get_match_ret(*sp, 0, i ? l : 0, fl, i ? replstr : 0);
+	*sp = get_match_ret(*sp, 0, i ? l : 0, fl, i ? replstr : 0, repllist);
 	if (! **sp && (((fl & SUB_MATCH) && !i) || ((fl & SUB_REST) && i)))
 	    return 0;
 	return 1;
@@ -2283,7 +2280,7 @@
 			}
 		    }
 		}
-		*sp = get_match_ret(*sp, 0, mlen, fl, replstr);
+		*sp = get_match_ret(*sp, 0, mlen, fl, replstr, repllist);
 		return 1;
 	    }
 	    break;
@@ -2298,7 +2295,7 @@
 		    t--;
 		set_pat_start(p, t-s);
 		if (pattrylen(p, t, s + l - t, umlen, ioff)) {
-		    *sp = get_match_ret(*sp, t - s, l, fl, replstr);
+		    *sp = get_match_ret(*sp, t - s, l, fl, replstr, repllist);
 		    return 1;
 		}
 		if (t > s+1 && t[-2] == Meta)
@@ -2314,7 +2311,7 @@
 		 ioff++, METAINC(t), umlen--) {
 		set_pat_start(p, t-s);
 		if (pattrylen(p, t, s + l - t, umlen, ioff)) {
-		    *sp = get_match_ret(*sp, t-s, l, fl, replstr);
+		    *sp = get_match_ret(*sp, t-s, l, fl, replstr, repllist);
 		    return 1;
 		}
 		if (*t == Meta)
@@ -2326,7 +2323,7 @@
 	    /* Smallest at start, but matching substrings. */
 	    set_pat_start(p, l);
 	    if (!(fl & SUB_GLOBAL) && pattry(p, s + l) && !--n) {
-		*sp = get_match_ret(*sp, 0, 0, fl, replstr);
+		*sp = get_match_ret(*sp, 0, 0, fl, replstr, repllist);
 		return 1;
 	    } /* fall through */
 	case (SUB_SUBSTR|SUB_LONG):
@@ -2357,7 +2354,8 @@
 			    }
 			}
 			if (!--n || (n <= 0 && (fl & SUB_GLOBAL))) {
-			    *sp = get_match_ret(*sp, t-s, mpos-s, fl, replstr);
+			    *sp = get_match_ret(*sp, t-s, mpos-s, fl,
+						replstr, repllist);
 			    if (mpos == t)
 				METAINC(mpos);
 			}
@@ -2396,7 +2394,7 @@
 	    set_pat_start(p, l);
 	    if ((fl & (SUB_LONG|SUB_GLOBAL)) == SUB_LONG &&
 		pattry(p, s + l) && !--n) {
-		*sp = get_match_ret(*sp, 0, 0, fl, replstr);
+		*sp = get_match_ret(*sp, 0, 0, fl, replstr, repllist);
 		return 1;
 	    }
 	    break;
@@ -2407,7 +2405,7 @@
 	    if (!(fl & SUB_LONG)) {
 		set_pat_start(p, l);
 		if (pattrylen(p, s + l, 0, 0, uml) && !--n) {
-		    *sp = get_match_ret(*sp, l, l, fl, replstr);
+		    *sp = get_match_ret(*sp, l, l, fl, replstr, repllist);
 		    return 1;
 		}
 	    }
@@ -2431,13 +2429,14 @@
 			    }
 			}
 		    }
-		    *sp = get_match_ret(*sp, t-s, mpos-s, fl, replstr);
+		    *sp = get_match_ret(*sp, t-s, mpos-s, fl,
+					replstr, repllist);
 		    return 1;
 		}
 	    }
 	    set_pat_start(p, l);
 	    if ((fl & SUB_LONG) && pattrylen(p, s + l, 0, 0, uml) && !--n) {
-		*sp = get_match_ret(*sp, l, l, fl, replstr);
+		*sp = get_match_ret(*sp, l, l, fl, replstr, repllist);
 		return 1;
 	    }
 	    break;
@@ -2478,7 +2477,7 @@
     }
 
     /* munge the whole string: no match, so no replstr */
-    *sp = get_match_ret(*sp, 0, 0, fl, 0);
+    *sp = get_match_ret(*sp, 0, 0, fl, 0, 0);
     return 1;
 }
 
Index: Test/D04parameter.ztst
===================================================================
RCS file: /cvsroot/zsh/zsh/Test/D04parameter.ztst,v
retrieving revision 1.10
diff -u -r1.10 D04parameter.ztst
--- Test/D04parameter.ztst	26 Apr 2005 09:51:30 -0000	1.10
+++ Test/D04parameter.ztst	17 Aug 2005 23:33:03 -0000
@@ -604,3 +604,11 @@
   print "${${foo}/?*/replacement}"
 0:Quoted zero-length strings are handled properly
 >
+
+  file=aleftkept
+  print ${file//(#b)(*)left/${match/a/andsome}}
+  print ${file//(#b)(*)left/${match//a/andsome}}
+0:Substitutions where $match is itself substituted in the replacement
+>andsomekept
+>andsomekept
+
-- 
Peter Stephenson <pws@xxxxxxxxxxxxxxxxxxxxxxxx>
Work: pws@xxxxxxx
Web: http://www.pwstephenson.fsnet.co.uk