diff --git a/mozilla/js2/src/js2engine.cpp b/mozilla/js2/src/js2engine.cpp
index b02306d3a2a..efc5f919598 100644
--- a/mozilla/js2/src/js2engine.cpp
+++ b/mozilla/js2/src/js2engine.cpp
@@ -805,12 +805,11 @@ namespace MetaData {
     }
 
     // XXX Default construction of an instance of the class
-    // that is the value at the top of the execution stack
-    js2val JS2Engine::defaultConstructor(JS2Metadata *meta, const js2val /* thisValue */, js2val /* argv */ [], uint32 /* argc */)
+    // that is the value of the passed in 'this'
+    js2val JS2Engine::defaultConstructor(JS2Metadata *meta, const js2val thisValue, js2val /* argv */ [], uint32 /* argc */)
     {
-        js2val v = meta->engine->top();
-        ASSERT(JS2VAL_IS_OBJECT(v) && !JS2VAL_IS_NULL(v));
-        JS2Object *obj = JS2VAL_TO_OBJECT(v);
+        ASSERT(JS2VAL_IS_OBJECT(thisValue) && !JS2VAL_IS_NULL(thisValue));
+        JS2Object *obj = JS2VAL_TO_OBJECT(thisValue);
         ASSERT(obj->kind == ClassKind);
         JS2Class *c = checked_cast<JS2Class *>(obj);
         if (c->prototype)
diff --git a/mozilla/js2/src/js2eval.cpp b/mozilla/js2/src/js2eval.cpp
index 60f45baac84..6b01520d5d3 100644
--- a/mozilla/js2/src/js2eval.cpp
+++ b/mozilla/js2/src/js2eval.cpp
@@ -459,8 +459,23 @@ namespace MetaData {
             return (JS2VAL_TO_BOOLEAN(x)) ? 1.0 : 0.0;
         if (JS2VAL_IS_STRING(x)) {
             String *str = JS2VAL_TO_STRING(x);
+            uint32 length = str->length();
+            if (length == 0)
+                return 0.0;
             const char16 *numEnd;
-            return stringToDouble(str->data(), str->data() + str->length(), numEnd);
+            // if the string begins with '0X' or '0x' (after white space), then
+            // read it as a hex integer.
+            const char16 *strStart = str->data();
+            const char16 *strEnd = strStart + length;
+            const char16 *str1 = skipWhiteSpace(strStart, strEnd);
+            if ((*str1 == '0') && ((str1[1] == 'x') || (str1[1] == 'X')))
+                return stringToInteger(str1, strEnd, numEnd, 16);
+            else {
+                float64 d = stringToDouble(str1, strEnd, numEnd);
+                if (numEnd == str1)
+                    return nan;
+                return d;
+            }
         }
         if (JS2VAL_IS_INACCESSIBLE(x))
             reportError(Exception::compileExpressionError, "Inappropriate compile time expression", engine->errorPos());
diff --git a/mozilla/js2/src/js2op_invocation.cpp b/mozilla/js2/src/js2op_invocation.cpp
index 2f5eacd610a..9890099acd9 100644
--- a/mozilla/js2/src/js2op_invocation.cpp
+++ b/mozilla/js2/src/js2op_invocation.cpp
@@ -38,11 +38,13 @@
             uint16 argCount = BytecodeContainer::getShort(pc);
             pc += sizeof(uint16);
             a = top(argCount + 1);
-            ASSERT(JS2VAL_IS_OBJECT(a) && !JS2VAL_IS_NULL(a));
+            if (!JS2VAL_IS_OBJECT(a) || JS2VAL_IS_NULL(a)) {
+                meta->reportError(Exception::badValueError, "object is not a constructor", errorPos());
+            }
             JS2Object *obj = JS2VAL_TO_OBJECT(a);
             if (obj->kind == ClassKind) {
                 JS2Class *c = checked_cast<JS2Class *>(obj);
-                a = c->construct(meta, JS2VAL_NULL, base(argCount), argCount);
+                a = c->construct(meta, a, base(argCount), argCount);
                 pop(argCount + 1);
                 push(a);
             }