667646 - (function f() { alert("" + f.caller); })() should alert null, not undefined

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jeff Walden [:Waldo]]

Attachment: Patch, plus tests for bug 666587

3.6 alerted null.  4.0, 5.0, and presumably everything since alerts undefined.  This contradicts my understanding of the property and our documentation, so we should go back to 3.6-era behavior:

https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Function/caller

If I had to guess, the changeset that introduce getValidCalleeObject (which I'm pretty sure I reviewed!) probably regressed this, but I don't really care enough to verify that or bisect a true regressor.

Comment 1

[Tom S. (please needinfo tschuster)]

Comment on attachment 542299 [details] [diff] [review]
Patch, plus tests for bug 666587

Review of attachment 542299 [details] [diff] [review]:
-----------------------------------------------------------------

I really like that we lost one level of indention here. I am not sure how much we care about getValidCalleeObject, but it looks like it was more or less created for ".caller", so i it should be okay to change the return value.

::: js/src/tests/ecma_5/extensions/function-properties.js
@@ +8,5 @@
> +}
> +
> +assertEq(foo.arguments, null);
> +assertEq(foo.caller, null);
> +foo();

Check foo.caller and foo.arguments.length here again. Just for the sake of it :)

Comment 2

[Jeff Walden [:Waldo]]

http://hg.mozilla.org/tracemonkey/rev/3fb152290879

Comment 3

[Chris Leary [:cdleary] (not checking bugmail)]

cdleary-bot mozilla-central merge info:
http://hg.mozilla.org/mozilla-central/rev/3fb152290879