for-in statement: null and undefined

[Kent Hansen]

Hi,
In the current public ES4 reference implementation [1], iterating over
null and undefined is a no-op instead of a TypeError, which is in line
with the proposal at [2] (which points out that existing web browsers
already do this). However, the most recent ES3.1 draft [3] does not
incorporate this change. It's not mentioned in Douglas Crockford's
recommendations for modifications to ES [4] either, nor in the proposed
incompatibilities [5]. So my question is, will this change be part of
ES3.1 or not (doesn't it have to, for ES4 compatibility's sake)? I can't
find a discussion of this issue anywhere.

By the way, in the ES4 reference implementation, iterating over strings
is a no-op as well; implementation bug, or are string properties not
enumerable in ES4? "X".hasOwnProperty(0) returns false, too.

Regards,
Kent

[1]
http://www.ecmascript.org/license.php?file=es4-pre-release.M2.linux-x86.tar.gz
[2] http://wiki.ecmascript.org/doku.php?id=proposals:bug_fixes
[3]
http://wiki.ecmascript.org/lib/exe/fetch.php?id=es3.1%3Aes3.1_proposal_working_draft&cache=cache&media=es3.1:tc39-es31-draft02jul08.pdf
[4] http://www.crockford.com/javascript/recommend.html
[5] http://www.ecmascript.org/es4/spec/incompatibilities.pdf