See bug 655270 comment 46.

Mass-modify - removal of no longer relevant blocking flags.

It's not super-clear from the original bug what the dream was here. It seems like a reasonable behaviour would be if this was the equivalent of the mozStorageStatementScoper noticing that a statement was concurrently being used on multiple threads. Since buggy code might not use mozStorageStatementScoper and the statement object would need to provide help anyways, the easiest debug algorithm would be to: - Have all statement methods check if mUsedOnThread is null. If null, assign the current thread. If non-null, assert it's the same thread as our thread. - Have Reset() clear mUsedOnThread. Any complaint from this would be valid/useful feedback I think, even if it's just failure to Reset() the statement in a timely fashion.

Per policy at https://wiki.mozilla.org/Bug_Triage/Projects/Bug_Handling/Bug_Husbandry#Inactive_Bugs. If this bug is not an enhancement request or a bug not present in a supported release of Firefox, then it may be reopened.