265544 - PL_PostEvent/nsEventQueueImpl::PostEvent error handling is odd

Status: RESOLVED INVALID

(Core :: XPCOM, defect)

Description

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

The error handling in nsEventQueueImpl::PostEvent (some of which comes from
PL_PostEvent) is odd.  In particular, it can return failure even when the event
is added to the queue.  Many clients assume that failure means the event should
be deleted.

The particular failure case I'm worried about is if _pl_NativeNotify fails in
PL_PostEvent.  This happens after the event is added to the event queue (so
basically ownership has been transferred).  Either PL_PostEvent should not
propagate this error or nsEventQueueImpl::PostEvent should not propagate the
error from PL_PostEvent (and should check the one other case where it can return
an error).

Comment 1

[Benjamin Smedberg]

ouch

Comment 2

[Darin Fisher]

PL_PostEvent/nsEventQueueImpl no longer exist.  See bug 326273.