Comment 54 for bug 274065

Last week Boris helped to understand this bug better, I promised to summarize the findings here.

In addition to the bug already reported above, Doug ran into another scenario that trigger the failure, with assertion

###!!! ASSERTION: nsNSSComponent is a sin
gleton, but instantiated multiple times!: '(0 == mInstanceCount)', file c:/builds/mobile/mozilla-central/security/manager/ssl/src/nsNS
SComponent.cpp, line 300

When we first try to init the XPCOM nsNSSComponent, we sometimes fail. No service object gets registered. As a result it will be retried at a later time, when someone else asks for the service.

Unfortunately the nsNSSComponent fails to clean up correctly. This is because there are strong references to it, despite the init failure, and therefore the XPCOM manager fails to clean up the failed instance.

Boris identified that the references are because of RegisterObserver. We must unregister on failure. The init code should get checked for other activity that needs to be undone.

I'd also like to add some self protection mechanism. After we do above cleanup, should we still run into multiple instances, the secondary instances should refrain from any activity.