1 files changed, 63 insertions, 0 deletions
diff --git a/js/src/builtin/Utilities.js b/js/src/builtin/Utilities.js
index c73bc5e7f..d5f233d05 100644
--- a/js/src/builtin/Utilities.js
+++ b/js/src/builtin/Utilities.js
@@ -229,6 +229,69 @@ function GetInternalError(msg) {
 // To be used when a function is required but calling it shouldn't do anything.
 function NullFunction() {}
 
+// Object Rest/Spread Properties proposal
+// Abstract operation: CopyDataProperties (target, source, excluded)
+function CopyDataProperties(target, source, excluded) {
+    // Step 1.
+    assert(IsObject(target), "target is an object");
+
+    // Step 2.
+    assert(IsObject(excluded), "excluded is an object");
+
+    // Steps 3, 6.
+    if (source === undefined || source === null)
+        return;
+
+    // Step 4.a.
+    source = ToObject(source);
+
+    // Step 4.b.
+    var keys = OwnPropertyKeys(source, JSITER_OWNONLY | JSITER_HIDDEN | JSITER_SYMBOLS);
+
+    // Step 5.
+    for (var index = 0; index < keys.length; index++) {
+        var key = keys[index];
+
+        // We abbreviate this by calling propertyIsEnumerable which is faster
+        // and returns false for not defined properties.
+        if (!callFunction(std_Object_hasOwnProperty, excluded, key) && callFunction(std_Object_propertyIsEnumerable, source, key))
+            _DefineDataProperty(target, key, source[key]);
+    }
+
+    // Step 6 (Return).
+}
+
+// Object Rest/Spread Properties proposal
+// Abstract operation: CopyDataProperties (target, source, excluded)
+function CopyDataPropertiesUnfiltered(target, source) {
+    // Step 1.
+    assert(IsObject(target), "target is an object");
+
+    // Step 2 (Not applicable).
+
+    // Steps 3, 6.
+    if (source === undefined || source === null)
+        return;
+
+    // Step 4.a.
+    source = ToObject(source);
+
+    // Step 4.b.
+    var keys = OwnPropertyKeys(source, JSITER_OWNONLY | JSITER_HIDDEN | JSITER_SYMBOLS);
+
+    // Step 5.
+    for (var index = 0; index < keys.length; index++) {
+        var key = keys[index];
+
+        // We abbreviate this by calling propertyIsEnumerable which is faster
+        // and returns false for not defined properties.
+        if (callFunction(std_Object_propertyIsEnumerable, source, key))
+            _DefineDataProperty(target, key, source[key]);
+    }
+
+    // Step 6 (Return).
+}
+
 /*************************************** Testing functions ***************************************/
 function outer() {
     return function inner() {