Re: How to substitute empty array element, or empty string

[Peter Stephenson <p.stephenson@samsung.com>]

On Wed, 22 Mar 2017 08:52:09 +0100
Sebastian Gniazdowski <psprint@zdharma.org> wrote:
> Hello,
> following does not work as expected:
> 
> % a=( a "" c ); print -rl -- "${(@)a//*/x}”
> x
> 
> x

This might be one of those "bug" things you sometimes read about for other
projects...

I believe I've sent the version that doesn't loop infinitely.

Other cases in igetmatch() may need adaption.

pws

diff --git a/Src/glob.c b/Src/glob.c
index 0fcb4e1..9ac0ae6 100644
--- a/Src/glob.c
+++ b/Src/glob.c
@@ -2969,7 +2969,7 @@ igetmatch(char **sp, Patprog p, int fl, int n, char *replstr,
 	    do {
 		/* loop over all matches for global substitution */
 		matched = 0;
-		for (; t < send; ioff++) {
+		for (; t <= send; ioff++) {
 		    /* Find the longest match from this position. */
 		    set_pat_start(p, t-s);
 		    if (pattrylen(p, t, umlen, 0, &patstralloc, ioff)) {
@@ -3018,15 +3018,19 @@ igetmatch(char **sp, Patprog p, int fl, int n, char *replstr,
 			 * which is already marked for replacement.
 			 */
 			matched = 1;
+			if (t == send)
+			    break;
 			while (t < mpos) {
 			    ioff++;
 			    umlen -= iincchar(&t, send - t);
 			}
 			break;
 		    }
+		    if (t == send)
+			break;
 		    umlen -= iincchar(&t, send - t);
 		}
-	    } while (matched);
+	    } while (matched && t < send);
 	    /*
 	     * check if we can match a blank string, if so do it
 	     * at the start.  Goodness knows if this is a good idea
diff --git a/Test/D04parameter.ztst b/Test/D04parameter.ztst
index cb9d50d..99f7dd9 100644
--- a/Test/D04parameter.ztst
+++ b/Test/D04parameter.ztst
@@ -2148,3 +2148,13 @@ F:behavior, see http://austingroupbugs.net/view.php?id=888
     [[ ${-} = [[:alnum:]]## ]] || print Failed 2
   }
 0:$- expansion correctly handles Dash token
+
+  a=(1 "" 3)
+  print -rl -- "${(@)a//*/x}"
+  a=""
+  print -rl -- "${(@)a//*/y}"
+0:Zero-length string match in parameter substitution
+>x
+>x
+>x
+>y