fix propertyIsEnumerable when using an index to access string

src/org/mozilla/javascript/NativeString.java

@@ -574,6 +574,18 @@ public boolean has(int index, Scriptable start) {
         return super.has(index, start);
     }
 
+    @Override
+    public int getAttributes(int index) {
+        if (0 <= index && index < string.length()) {
+          int attribs = READONLY | PERMANENT;
+          if (Context.getContext().getLanguageVersion() < Context.VERSION_ES6) {
+              attribs |= DONTENUM;
+          }
+          return attribs;
+        }
+        return super.getAttributes(index);
+    }
+
     @Override
     protected Object[] getIds(boolean nonEnumerable, boolean getSymbols)
     {

src/org/mozilla/javascript/regexp/RegExpImpl.java

@@ -50,23 +50,36 @@ public Object action(Context cx, Scriptable scope,
         switch (actionType) {
           case RA_MATCH:
             {
-                NativeRegExp re = createRegExp(cx, scope, args, 1, false);
-                Object rval = matchOrReplace(cx, scope, thisObj, args,
-                                             this, data, re);
+                int optarg = Integer.MAX_VALUE;
+                if (cx.getLanguageVersion() < Context.VERSION_1_6) {
+                    optarg = 1;
+                }
+
+                NativeRegExp re = createRegExp(cx, scope, args, optarg, false);
+                Object rval = matchOrReplace(cx, scope, thisObj, args, this, data, re);
                 return data.arrayobj == null ? rval : data.arrayobj;
             }
 
           case RA_SEARCH:
             {
-                NativeRegExp re = createRegExp(cx, scope, args, 1, false);
-                return matchOrReplace(cx, scope, thisObj, args,
-                                      this, data, re);
+                int optarg = Integer.MAX_VALUE;
+                if (cx.getLanguageVersion() < Context.VERSION_1_6) {
+                    optarg = 1;
+                }
+
+                NativeRegExp re = createRegExp(cx, scope, args, optarg, false);
+                return matchOrReplace(cx, scope, thisObj, args, this, data, re);
             }
 
           case RA_REPLACE:
             {
-                boolean useRE = (args.length > 0 && args[0] instanceof NativeRegExp)
-                                || args.length > 2;
+                boolean useRE = args.length > 0 && args[0] instanceof NativeRegExp;
+
+                // ignore other parameters
+                if (cx.getLanguageVersion() < Context.VERSION_1_6) {
+                    useRE |= args.length > 2;
+                }
+
                 NativeRegExp re = null;
                 String search = null;
                 if (useRE) {

testsrc/jstests/es6/string.js

@@ -0,0 +1,25 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+load("testsrc/assert.js");
+
+(function TestIsEnumerable() {
+  var obj = new Object("z");
+
+  assertTrue(obj.propertyIsEnumerable('0'));
+})();
+
+(function TestReplaceNotUsedArguments() {
+  assertEquals("axdefg", "abcdefg".replace("bc", "x", "not used"));
+})();
+
+(function TestMatchNotUsedArguments() {
+  assertNull("abcdefg".match("AB", "not used"));
+})();
+
+(function TestSearchNotUsedArguments() {
+  assertEquals(2, "abcdEfg".search("cd", "not used"));
+})();
+
+"success";

testsrc/org/mozilla/javascript/tests/es6/NativeStringTest.java

@@ -0,0 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.javascript.tests.es6;
+
+import org.mozilla.javascript.Context;
+import org.mozilla.javascript.drivers.LanguageVersion;
+import org.mozilla.javascript.drivers.RhinoTest;
+import org.mozilla.javascript.drivers.ScriptTestsBase;
+
+@RhinoTest("testsrc/jstests/es6/string.js")
+@LanguageVersion(Context.VERSION_ES6)
+public class NativeStringTest extends ScriptTestsBase
+{
+}