--- a/js/src/jsarray.cpp
+++ b/js/src/jsarray.cpp
@@ -1765,26 +1765,32 @@ InitArrayTypes(JSContext *cx, TypeObject
                 continue;
             Type valtype = GetValueType(cx, vector[i]);
             types->addType(cx, valtype);
         }
     }
     return true;
 }
 
-static JSBool
-InitArrayElements(JSContext *cx, JSObject *obj, jsuint start, jsuint count, const Value *vector, bool updateTypes)
+enum ShouldUpdateTypes
+{
+    UpdateTypes = true,
+    DontUpdateTypes = false
+};
+
+static bool
+InitArrayElements(JSContext *cx, JSObject *obj, uint32 start, uint32 count, const Value *vector, ShouldUpdateTypes updateTypes)
 {
     JS_ASSERT(count <= MAX_ARRAY_INDEX);
 
     if (count == 0)
-        return JS_TRUE;
+        return true;
 
     if (updateTypes && !InitArrayTypes(cx, obj->getType(cx), vector, count))
-        return JS_FALSE;
+        return false;
 
     /*
      * Optimize for dense arrays so long as adding the given set of elements
      * wouldn't otherwise make the array slow.
      */
     do {
         if (!obj->isDenseArray())
             break;
@@ -1807,41 +1813,41 @@ InitArrayElements(JSContext *cx, JSObjec
         JS_ASSERT_IF(count != 0, !obj->getDenseArrayElement(newlen - 1).isMagic(JS_ARRAY_HOLE));
         return true;
     } while (false);
 
     const Value* end = vector + count;
     while (vector < end && start <= MAX_ARRAY_INDEX) {
         if (!JS_CHECK_OPERATION_LIMIT(cx) ||
             !SetArrayElement(cx, obj, start++, *vector++)) {
-            return JS_FALSE;
+            return false;
         }
     }
 
     if (vector == end)
-        return JS_TRUE;
+        return true;
 
     /* Finish out any remaining elements past the max array index. */
     if (obj->isDenseArray() && !obj->makeDenseArraySlow(cx))
-        return JS_FALSE;
+        return false;
 
     JS_ASSERT(start == MAX_ARRAY_INDEX + 1);
     AutoValueRooter tvr(cx);
     AutoIdRooter idr(cx);
     Value idval = DoubleValue(MAX_ARRAY_INDEX + 1);
     do {
         *tvr.addr() = *vector++;
         if (!js_ValueToStringId(cx, idval, idr.addr()) ||
             !obj->setGeneric(cx, idr.id(), tvr.addr(), true)) {
-            return JS_FALSE;
+            return false;
         }
         idval.getDoubleRef() += 1;
     } while (vector != end);
 
-    return JS_TRUE;
+    return true;
 }
 
 #if 0
 static JSBool
 InitArrayObject(JSContext *cx, JSObject *obj, jsuint length, const Value *vector)
 {
     JS_ASSERT(obj->isArray());
 
@@ -2235,17 +2241,17 @@ js::array_sort(JSContext *cx, uintN argc
         }
 
         /*
          * We no longer need to root the scratch space for the merge sort, so
          * unroot it now to make the job of a potential GC under
          * InitArrayElements easier.
          */
         vec.resize(n);
-        if (!InitArrayElements(cx, obj, 0, jsuint(n), vec.begin(), false))
+        if (!InitArrayElements(cx, obj, 0, jsuint(n), vec.begin(), DontUpdateTypes))
             return false;
     }
 
     /* Set undefs that sorted after the rest of elements. */
     while (undefs != 0) {
         --undefs;
         if (!JS_CHECK_OPERATION_LIMIT(cx) || !SetArrayElement(cx, obj, n++, UndefinedValue()))
             return false;
@@ -2265,17 +2271,17 @@ js::array_sort(JSContext *cx, uintN argc
  */
 static bool
 array_push_slowly(JSContext *cx, JSObject *obj, CallArgs &args)
 {
     jsuint length;
 
     if (!js_GetLengthProperty(cx, obj, &length))
         return false;
-    if (!InitArrayElements(cx, obj, length, args.length(), args.array(), true))
+    if (!InitArrayElements(cx, obj, length, args.length(), args.array(), UpdateTypes))
         return false;
 
     /* Per ECMA-262, return the new array length. */
     jsdouble newlength = length + jsdouble(args.length());
     args.rval().setNumber(newlength);
     return js_SetLengthProperty(cx, obj, newlength);
 }
 
@@ -2549,17 +2555,17 @@ array_unshift(JSContext *cx, uintN argc,
                         !SetOrDeleteArrayElement(cx, obj, upperIndex, hole, tvr.value())) {
                         return JS_FALSE;
                     }
                 } while (last != 0);
             }
         }
 
         /* Copy from args to the bottom of the array. */
-        if (!InitArrayElements(cx, obj, 0, args.length(), args.array(), true))
+        if (!InitArrayElements(cx, obj, 0, args.length(), args.array(), UpdateTypes))
             return JS_FALSE;
 
         newlen += args.length();
     }
     if (!js_SetLengthProperty(cx, obj, newlen))
         return JS_FALSE;
 
     /* Follow Perl by returning the new array length. */