test-hup hangs on AIX. Under ksh89 on AIX (the default shell),
echo Hello; while [ ! -s not-there ]; do true; done
produces no output while the loop executes. Replacing 'true' with 'sleep 0'
fixes, as does using a less broken shell. ksh93 is fine.
Update check-code.py to look for this, and make same change in test-serve.t.
In fact test-serve works fine, probably because of additional commands between
echo and the loop, but that's a subtlety not easy to test for.
The 'while kill -0' recipe can cause a livelock if the process we're waiting
to die is a normal child process. If it becomes a zombie that the shell
doesn't reap (shell bug?), it will continue to be able to accept
signals. So instead, we just wait(1).
We need to wait until a journal exists AND is non-empty before
aborting a transaction to get stable output. We move the kill wait
outside the fifo block to avoid potential deadlock.
Before this patch undo.bookmarks was created on bookmarks write and
not with other transaction-related files. There were two issues: first
is that if you have changed bookmarks few times after a transaction
happened, rollback will give you a state which can point to
non-existing revision. Second is that if you have not changed
bookmarks after a transaction, rollback will touch your state anyway.
This change also adds `localrepo._writejournal` method, which can be
used by other extensions to save their transaction-related backup in
right time.
