dirstate: split write to write changes into files other than .hg/dirstate
'_writedirstate()' is used mainly for "transactional dirstate". See
the wiki page below for detail about it.
https://mercurial.selenic.com/wiki/DirstateTransactionPlan
--- a/mercurial/dirstate.py Thu Oct 08 01:41:30 2015 +0900
+++ b/mercurial/dirstate.py Thu Oct 08 01:41:30 2015 +0900
@@ -622,6 +622,9 @@
time.sleep(delaywrite)
st = self._opener(self._filename, "w", atomictemp=True)
+ self._writedirstate(st)
+
+ def _writedirstate(self, st):
# use the modification time of the newly created temporary file as the
# filesystem's notion of 'now'
now = util.fstat(st).st_mtime