prototype: Make String#scan explicitly return a string. Closes #6350.

CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Make String#scan explicitly return a string. This prevents possible issues with methods expecting input data that is typeof == 'string'. Closes #6350. [AndrewRev, Tobie Langel]
+
 * Add Array#intersect for set intersection. Returns a new array containing all items common to the array and the argument, with duplicates removed (clone of the Ruby & method).   [Thomas Fuchs]
   Example:
     [1,1,3,5].intersect([1,2,3]) -> [1,3]

src/string.js

@@ -41,7 +41,7 @@ Object.extend(String.prototype, {
   
   scan: function(pattern, iterator) {
     this.gsub(pattern, iterator);
-    return this;
+    return String(this);
   },
   
   truncate: function(length, truncation) {

test/unit/string.html

@@ -132,11 +132,12 @@
     
     testScan: function() {with(this) {
       var source = 'foo boo boz', results = [];
-      source.scan(/[o]+/, function(match) {
+      var str = source.scan(/[o]+/, function(match) {
         results.push(match[0].length);
       });
       assertEnumEqual([2, 2, 1], results);
       assertEqual(source, source.scan(/x/, fail));
+      assert(typeof str == 'string');
     }},
     
     testToArray: function() {with(this) {