1135773 - The cycle collector should not depend on QI nulling out the return value in case of failure

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[Andrew McCreight [:mccr8]]

See the discussion in bug 723248.  This could cause some weird crashes.  The simplest thing to do is probably to just null out the return value before we call QI.  That won't help if a QI intentionally mangles the return value in case of failure, but that seems unlikely.  Bug 1135772 has some examples of QIs failing to null out the return value.

Comment 1

[Andrew McCreight [:mccr8]]

Attachment: Initialize QI return values to null in the cycle collector.

try run: https://treeherder.mozilla.org/#/jobs?repo=try&revision=22b490430a79

Comment 2

[Andrew McCreight [:mccr8]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/2c50d60676c7

Comment 3

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/2c50d60676c7