Improve array to string conversion.

test/mjsunit/uri.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 58 matching lines @@
 assertEquals(cc3, decodeURI(encodeURI(s3)).charCodeAt(0));
 assertEquals(cc4, decodeURI(encodeURI(s4)).charCodeAt(0));
 assertEquals(cc5, decodeURI(encodeURI(s5)).charCodeAt(0));
 assertEquals(cc6, decodeURI(encodeURI(s6)).charCodeAt(0));
 assertEquals(cc7, decodeURI(encodeURI(s7)).charCodeAt(0));
 assertEquals(cc8_1, decodeURI(encodeURI(s8)).charCodeAt(0));
 assertEquals(cc8_2, decodeURI(encodeURI(s8)).charCodeAt(1));
 assertEquals(cc9_1, decodeURI(encodeURI(s9)).charCodeAt(0));
 assertEquals(cc9_2, decodeURI(encodeURI(s9)).charCodeAt(1));
 assertEquals(cc10, decodeURI(encodeURI(s10)).charCodeAt(0));
+
+assertEquals("", decodeURI(""));
+assertEquals("", encodeURI(""));
+
+function test(string) {
+  assertEquals(string, decodeURI(encodeURI(string)));
+}
+
+test("\u1234\u0123\uabcd");
+test("abcd");
+test("ab<\u1234\u0123");
+test("ab\u1234<\u0123");