mq: use dirstateguard instead of dirstate.invalidate (qrefresh)
Before this patch, "mq.queue.refresh()" uses "dirstate.invalidate()"
as a kind of "restore .hg/dirstate to the original status" during a failure.
But it just discards changes in memory, and doesn't actually restore
".hg/dirstate". Then, it can't work as expected, if "dirstate.write()"
is executed while processing.
This patch uses "dirstateguard" instead of "dirstate.invalidate()" to
restore ".hg/dirstate" during a failure even if "dirstate.write()" is
executed before a failure.
This patch also removes "beginparentchage()" and "endparentchange()",
because "dirstateguard" makes them useless.
This is a part of preparations to fix the issue that the recent (in
memory) dirstate isn't visible to external processes (e.g. "precommit"
hook).
os = <unloaded module 'os'>
os.system = <built-in function system>
os = <module 'os' from '?'>
util = <unloaded module 'util'>
util.system = <function system at 0x?>
util = <module 'mercurial.util' from '?'>
util.system = <function system at 0x?>
fred = <unloaded module 're'>
re = <unloaded module 'sys'>
fred = <unloaded module 're'>
fred.sub = <function sub at 0x?>
fred = <proxied module 're'>
re = <unloaded module 'sys'>
re.stderr = <open file '<whatever>', mode 'w' at 0x?>
re = <proxied module 'sys'>
node = <module 'mercurial.node' from '?'>