Fix issue 785. For-in now works on strings: for (var i in "asdf") now works...

test/mjsunit/for-in-special-cases.js

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 44 matching lines @@
 }
 
 for (var j = 0; j < 10; ++j) {
   assertTrue(for_in_undefined());
   gc();
 }
 
 assertEquals(10, i);
 assertEquals(10, j);
 
+
+function Accumulate(x) {
+  var accumulator = "";
+  for (var i in x) {
+    accumulator += i;
+  }
+  return accumulator;
+}
+
+for (var i = 0; i < 3; ++i) {
+  var elements = Accumulate("abcd");
+  // We do not assume that for-in enumerates elements in order.
+  assertTrue(-1 != elements.indexOf("0"));
+  assertTrue(-1 != elements.indexOf("1"));
+  assertTrue(-1 != elements.indexOf("2"));
+  assertTrue(-1 != elements.indexOf("3"));
+  assertEquals(4, elements.length);
+}
+
+function for_in_string_prototype() {
+
+  var x = new String("abc");
+  x.foo = 19;
+  function B() {
+    this.bar = 5;
+    this[7] = 4;
+  }
+  B.prototype = x;
+
+  var y = new B();
+  y.gub = 13;
+
+  var elements = Accumulate(y);
+  var elements1 = Accumulate(y);
+  // If for-in returns elements in a different order on multiple calls, this
+  // assert will fail.  If that happens, consider if that behavior is OK.
+  assertEquals(elements, elements1, "For-in elements not the same both times.");
+  // We do not assume that for-in enumerates elements in order.
+  assertTrue(-1 != elements.indexOf("0"));
+  assertTrue(-1 != elements.indexOf("1"));
+  assertTrue(-1 != elements.indexOf("2"));
+  assertTrue(-1 != elements.indexOf("7"));
+  assertTrue(-1 != elements.indexOf("foo"));
+  assertTrue(-1 != elements.indexOf("bar"));
+  assertTrue(-1 != elements.indexOf("gub"));
+  assertEquals(13, elements.length);
+
+  elements = Accumulate(x);
+  assertTrue(-1 != elements.indexOf("0"));
+  assertTrue(-1 != elements.indexOf("1"));
+  assertTrue(-1 != elements.indexOf("2"));
+  assertTrue(-1 != elements.indexOf("foo"));
+  assertEquals(6, elements.length);
+}
+
+for_in_string_prototype();
+for_in_string_prototype();