mq: use .invalidate to cancel dirty mq state when cancelling transaction Before the code optimistically relied on savedirty not being called a cancelled transaction. If it was called it could save incorrect data. Instead we now start using the invalidate method introduced in b169ba60eebe.

mq: make qsave implementation more explicit It wasn't obvious from the code how qsave mocked around with .hg/patches and .hg/patches.? and what was going on. This makes it more explicit so it will survive future refactorings.

mq: consistently use boolean values for dirty flags

mq: minor cleanup

tag: lock before tagging

tests: lock before creating transaction in test-filelog

debugbuilddag: lock repo before starting transaction

rebase: take locks in the right order repo.lock was taken before repo.wlock - that could in principle cause a deadlock.