pushkey: do not exchange obsole markers if feature is disabled
This apply to both push and pull both when client or server.
$ "$TESTDIR/hghave" inotify || exit 80
$ hg init
$ touch a b
$ hg add a b
$ rm b
status without inotify
$ hg st
A a
! b
$ echo "[extensions]" >> $HGRCPATH
$ echo "inotify=" >> $HGRCPATH
inserve
$ hg inserve -d --pid-file=hg.pid 2>&1
$ cat hg.pid >> "$DAEMON_PIDS"
status
$ hg st
A a
! b
? hg.pid
$ sleep 1
Are we able to kill the service? if not, the service died on some error
$ kill `cat hg.pid`