Don't take iterable path in ArrayFrom if items[@@iterator] is null

src/v8natives.js

Index: src/v8natives.js
diff --git a/src/v8natives.js b/src/v8natives.js
index ac96f6391edb1b5377bc169da210e5053f827c93..8ffddd5adb4d17a8f97d4a7958b83ddc2bdde86a 100644
--- a/src/v8natives.js
+++ b/src/v8natives.js
@@ -654,6 +654,16 @@ function Delete(obj, p, should_throw) {
 }
 
 
+// ES6, draft 12-24-14, section 7.3.8
+function GetMethod(obj, p) {
+  // Assert: obj is not null or undefined

[arv (Not doing code reviews), 2015/01/21 15:05:18]

Remove?

[caitp (gmail), 2015/01/21 17:21:49]

Acknowledged.

+  var func = obj[p];
+  if (IS_NULL_OR_UNDEFINED(func)) return;

[arv (Not doing code reviews), 2015/01/21 15:05:18]

return UNDEFINED;

for clarity?

[caitp (gmail), 2015/01/21 17:21:49]

Acknowledged.

+  if (IS_SPEC_FUNCTION(func)) return func;
+  throw MakeTypeError('called_non_callable', [typeof func]);

[arv (Not doing code reviews), 2015/01/21 15:05:18]

maybe update this to use the new better error message than typeof?

[caitp (gmail), 2015/01/21 17:21:49]

I had a go at it, but it will end up implicating Array.from rather than the
property itself, which is kind of weird

+}
+
+
 // Harmony proxies.
 function DefineProxyProperty(obj, p, attributes, should_throw) {
   // TODO(rossberg): adjust once there is a story for symbols vs proxies.