750111 - mozMovementX is transient and becomes zero later

Status: RESOLVED FIXED

(Core :: DOM: Events, defect)

Description

[Alon Zakai (:azakai)]

Attachment: testcase

mousemove events have valid mozMovementX and Y values, but if that event object is saved somewhere and processed later, the value of mozMovementX is 0. This is quite surprising and a problem for web pages that want to process the event info later.

For example, if you receive such an event and do a setTimeout whose closure captures the event, the timeout will print 0 for mozMovementX.

The attached testcase shows this, search for 'zz' to see the relevant lines. Looking in the web console it is clear mozMovementX is valid when received, but zero'd out later.

Comment 1

[Olli Pettay [:smaug][[e-mail]]]

nsDOMUIEvent::DuplicatePrivateData() should handle also movementX/Y

Comment 2

[Alex Keybl [:akeybl]]

This is a bug in the newly implemented Mouse Lock API. Tracking for FF14.

Comment 3

[David Humphrey (:humph)]

As an aside, this test case is triggering bug 731350 for me when I go fullscreen.

Comment 4

[David Humphrey (:humph)]

Attachment: Patch v1

Comment 5

[Lukas Blakk [:lsblakk] use ?needinfo]

seems like there's a rash of tracking flags being reset going around.  fixing. we're tracking this for 14.

Comment 6

[David Humphrey (:humph)]

Attachment: Patch v2 (r=smaug)

I wanted to run this through try server before updating, but now that I've done that, this looks good.

https://tbpl.mozilla.org/?tree=Try&rev=6d128e6de11b

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/4d1a47d43ce5

Should this have an automated test?

Comment 8

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/4d1a47d43ce5

Comment 9

[Lukas Blakk [:lsblakk] use ?needinfo]

Please nominate for Aurora approval so we can uplift.

Comment 10

[Olli Pettay [:smaug][[e-mail]]]

Comment on attachment 622237 [details] [diff] [review]
Patch v2 (r=smaug)

[Approval Request Comment]
Bug caused by (feature/regressing bug #): NA
User impact if declined: buggy behavior in certain cases
Testing completed (on m-c, etc.): in m-c about a month
Risk to taking this patch (and alternatives if risky): very low risk 
String or UUID changes made by this patch: NA

Comment 11

[Alex Keybl [:akeybl]]

Comment on attachment 622237 [details] [diff] [review]
Patch v2 (r=smaug)

[Triage Comment]
Low risk fix for new feature. Approved for Beta 14.

Comment 12

[Olli Pettay [:smaug][[e-mail]]]

https://hg.mozilla.org/releases/mozilla-beta/rev/d54548c3b081