diff -r 10d26626c426 -r 69fb5d5d734a rt/emul/mini/src/main/resources/org/apidesign/vm4brwsr/emul/lang/java_lang_String.js
--- a/rt/emul/mini/src/main/resources/org/apidesign/vm4brwsr/emul/lang/java_lang_String.js	Tue May 06 08:36:54 2014 +0200
+++ b/rt/emul/mini/src/main/resources/org/apidesign/vm4brwsr/emul/lang/java_lang_String.js	Mon May 12 11:18:46 2014 +0200
@@ -3,15 +3,17 @@
 vm.java_lang_String(false);
 
 Array.at = function(arr, indx, value) {
-  if (indx < 0 || indx >= arr.length) {
-      var e = vm.java_lang_ArrayIndexOutOfBoundsException(true);
-      e.constructor.cons__VLjava_lang_String_2.call(e, indx.toString());
-      throw e;
+  var prev = arr[indx];
+  if (typeof prev === 'undefined' && (x < 0 || indx >= arr.length)) {
+    var e = vm.java_lang_ArrayIndexOutOfBoundsException(true);
+    e.constructor.cons__VLjava_lang_String_2.call(e, indx.toString());
+    throw e;
   }
   if (arguments.length === 3) {
-      arr[indx] = value;
+    arr[indx] = value;
+  } else {
+    return prev;
   }
-  return arr[indx];
 };
 Array.prototype.getClass__Ljava_lang_Class_2 = function() {
   return vm.java_lang_Class(false).defineArray__Ljava_lang_Class_2Ljava_lang_String_2Ljava_lang_Object_2(this.jvmName, this.fnc);