107585 - nsPrefBranch calls getService on shutdown; should register shutdown listener

Status: VERIFIED FIXED

(Core :: Preferences: Backend, defect)

Description

[David Epstein]

reproduced with 10/27 debug mozilla nightly build.
1. Set breakpoint in nsComponentManager.cpp: line 2075
2. Launch app in the debugger (F5).
3. Quit the app.
4. Check the stack trace.
5. Press F5 to advance debugger until you see ~nsPrefBranch in stack trace. Then
doubleclick on destructor line
Result: ~nsPrefBranch() calls do_GetService
Expected: Should register shutdown listener. 

Here's the source of the destructor:
nsPrefBranch::~nsPrefBranch()
{
   freeObserverList();
   nsCOMPtr<nsIObserverService> observerService = 
   do_GetService(NS_OBSERVERSERVICE_CONTRACTID);
   if (observerService)
      observerService->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
}

Comment 1

[David Epstein]

this results in warning msg when mozilla is shutdown (bug 107391)

Comment 2

[Alec Flett]

ironically it looks like we're just removing ourselves as a startup observer
the better choice would be to just make prefs add itself as a weak listener, and
then remove all this stuff at the end.

Comment 3

[Samir Gehani]

-> Preferences: Backend

Comment 4

[Brian Nesse (gone)]

Actually we already are added as a weak reference. All we have to do is not
remove ourselves.

Comment 5

[Brian Nesse (gone)]

Attachment: Patch to not remove observer

Comment 6

[Doug Turner (:dougt)]

Comment on attachment 55786 [details] [diff] [review]
Patch to not remove observer

looks good.

Comment 7

[Alec Flett]

Comment on attachment 55786 [details] [diff] [review]
Patch to not remove observer

sr=alecf

Comment 8

[Brian Nesse (gone)]

Fix checked in.

Comment 9

[David Epstein]

verified with 11/2 nightly mozilla build. Removed the observer remover from
nsPrefBranch.cpp. nsPrefBranch destructor no longer appearing in the stack track