889778 - nsDOMCamaraManager: Move NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY to the begin of QI

Status: RESOLVED FIXED

(Core :: DOM: Device Interfaces, defect)

Description

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh]]

See https://bugzilla.mozilla.org/show_bug.cgi?id=883741#c9
and 
https://bugzilla.mozilla.org/show_bug.cgi?id=883741#c12

I did a test by changing 
nsRefPtr<nsDOMCameraManager> mCameraManager;
to 
nsCOMPtr<nsDOMCameraManager> mCameraManager;
in Navigator.h 

And I did see  ###!!! ASSERTION: QueryInterface needed: 'query_result.get() == mRawPtr', file ../../dist/include/nsCOMPtr.h, line 547

So we should move NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY to the begin of QI.

Comment 1

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh]]

It seems the assertion is already there without my test patch.

Comment 2

[Mike Habicher [:mikeh] (high bugzilla latency)]

Yoink.

Comment 3

[Mike Habicher [:mikeh] (high bugzilla latency)]

Attachment: NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY to the begin of QI, v1

Comment 4

[Mike Habicher [:mikeh] (high bugzilla latency)]

[Blocking Requested - why for this release]: without this patch, the CameraManager is not able to function as a weak nsIObserver: calls to AddObserver(..., true /* weak */) will always fail.

Comment 5

[Mike Habicher [:mikeh] (high bugzilla latency)]

Attachment: NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY to the begin of QI, v2

Bonus version that moves NS_WRAPPERCACHE... and does proper error-checking.

try-server push: https://tbpl.mozilla.org/?tree=Try&rev=33bf9d76141c

Comment 6

[Mike Habicher [:mikeh] (high bugzilla latency)]

https://hg.mozilla.org/integration/b2g-inbound/rev/408786bfc72a

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/408786bfc72a