812887 - nsUserFontSet/nsFontFaceLoader do not check result of nsIChannel::AsyncOpen, resulting in leaks

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[Nils Maier [:nmaier]]

nsUserFontSet will set up a channel and CORS proxy, but fail to tear down the references should nsIChannel::AsyncOpen fail, thus leaking the instance itself and referenced objects like said channel.

Code in question:
http://mxr.mozilla.org/mozilla-central/source/layout/style/nsFontFaceLoader.cpp#383
Note how the code will call fontLoader->DropChannel should listener->Init() fail, but not when channel->AsyncOpen fails a couple of lines down the block.

This blocks (mochikit-o orange due to leaks) my fix for bug 719180, which, as a side effect, will make the channel fail early on AsyncOpen in some cases where before it would only fail later via OnStopRequest.
However, even without the fix from bug 719180 there are cases where AsyncOpen might fail early and hence has nsUserStyleSet leak.

Comment 1

[Nils Maier [:nmaier]]

Attachment: Fix nsUserFontSet not dropping the channel when nsIChannel::AsyncOpen fails

This will correctly call DropChannel() not only if listener->Init() fails, but also when channel->AsyncOpen() does fail.

Green try with that patch (same code, different name):
https://tbpl.mozilla.org/?tree=Try&rev=aa22b56b4cfb
The other changesets can be considered tests; would be leak-orange on mochikit-o without this patch.

Comment 2

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 682893 [details] [diff] [review]
Fix nsUserFontSet not dropping the channel when nsIChannel::AsyncOpen fails

r=me

Comment 3

[Nils Maier [:nmaier]]

Checkin-needed. Green try: https://tbpl.mozilla.org/?tree=Try&rev=aa22b56b4cfb

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/5b43d9de3c05

Comment 5

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/5b43d9de3c05

Comment 6

[Jason Duell]

Comment on attachment 682893 [details] [diff] [review]
Fix nsUserFontSet not dropping the channel when nsIChannel::AsyncOpen fails

See bug 719180 comment 43

Comment 7

[Jason Duell]

https://hg.mozilla.org/releases/mozilla-aurora/rev/db9a8576a8fd
https://hg.mozilla.org/releases/mozilla-b2g18/rev/f1c819ce835c