600657 - Mozmill IDE breaks every test containing "let" on recent trunk Firefox builds

Status: RESOLVED DUPLICATE of bug 596580

(Core :: JavaScript Engine, defect)

Description

[Adrian Kalla [:adriank]]

Starting with Firefox 4.0 nightlies from September, 15th, running tests using "let" instead of "var" or tests using shared modules containing "let" breaks them on the first encounter of "let". 
This happens *only* when starting the tests from Mozmill's IDE. Running the same tests from the command line works without a problem.

The error console show this kind of errors:
Error: missing ; before statement
Source File: resource://mozmill/modules/frame.js -> file:///Users/mozilla/sources/mozmill-tests-mine/shared-modules/testDownloadsAPI.js
Line: 394, Column: 4
Source Code:
    let ioSvc = Cc["@mozilla.org/network/io-service;1"] 


A possible reason for that could be Tracemonkey/Jaegermonkey landings on Sept., 14th:
http://hg.mozilla.org/mozilla-central/rev/0463cba05920
http://hg.mozilla.org/mozilla-central/rev/09b657f24840

The first (Mac) build that causes the problems used this revision:
http://hg.mozilla.org/mozilla-central/rev/0caec4ddff74

I could reproduce that behavior on Mac OSX 10.6 and Windows XP. I didn't test on Linux.

Comment 1

[Aaron Train [:aaronmt]]

Can reproduce with |let foo = bar;|

Expected: bar is not defined
Actual: missing ; before statement

Comment 2

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Adrian, do you have the changesets for both of the builds so we can see the pushlog? thanks.

Comment 3

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Robert, looks like it's similar to what has been reported later on for the AOM on bug 601458. We would still need a better range to isolate the causing patch.

Comment 4

[Adrian Kalla [:adriank]]

(In reply to comment #2)
> Adrian, do you have the changesets for both of the builds so we can see the
> pushlog? thanks.

this is the changeset of the last working Mac build:
http://hg.mozilla.org/mozilla-central/rev/5588c9796f0b

Comment 5

[David Mandelin [:dmandelin]]

Smells like fallout from bug 540675 (http://hg.mozilla.org/mozilla-central/rev/33bf77bcf1a0).

Comment 6

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

I think this is a dup of bug 596580. Doesn't look like http://hg.mozilla.org/tracemonkey/rev/09ebe83273b7 has been merged to m/c yet.

Comment 7

[Henrik Skupin [:whimboo][⌚️UTC+1]]

(In reply to comment #6)
> I think this is a dup of bug 596580. Doesn't look like
> http://hg.mozilla.org/tracemonkey/rev/09ebe83273b7 has been merged to m/c yet.

It is. Now that bug 596580 has been landed, Mozmill works fine.