tests/test-nointerrupt.t

exchange: move simple narrow changegroup generation from extension

The narrow extension completely replaced the function generating the
changegroup part when a narrow changegroup was requested. Previous
commits have taught the in-core changegroup code how to filter files
based on a matcher. This commit teaches the in-core bundle2 part
generation code to construct a matcher based on arguments. It
will also emit a bundle2 part describing the narrow spec.

I believe the changegroup part generation code in the narrow extension
is now limited to ellipsis serving mode. i.e. core is now capable
of narrow changegroup generation when ellipsis mode is disabled.

Differential Revision: https://phab.mercurial-scm.org/D4014

Dummy extension simulating unsafe long running command
  $ cat > sleepext.py <<EOF
  > import itertools
  > import time
  > 
  > from mercurial.i18n import _
  > from mercurial import registrar
  > 
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > 
  > @command(b'sleep', [], _(b'TIME'), norepo=True)
  > def sleep(ui, sleeptime=b"1", **opts):
  >     with ui.uninterruptable():
  >         for _i in itertools.repeat(None, int(sleeptime)):
  >             time.sleep(1)
  >         ui.warn(b"end of unsafe operation\n")
  >     ui.warn(b"%s second(s) passed\n" % sleeptime)
  > EOF

Kludge to emulate timeout(1) which is not generally available.
  $ cat > timeout.py <<EOF
  > from __future__ import print_function
  > import argparse
  > import signal
  > import subprocess
  > import sys
  > import time
  > 
  > ap = argparse.ArgumentParser()
  > ap.add_argument('-s', nargs=1, default='SIGTERM')
  > ap.add_argument('duration', nargs=1, type=int)
  > ap.add_argument('argv', nargs='*')
  > opts = ap.parse_args()
  > try:
  >     sig = int(opts.s[0])
  > except ValueError:
  >     sname = opts.s[0]
  >     if not sname.startswith('SIG'):
  >         sname = 'SIG' + sname
  >     sig = getattr(signal, sname)
  > proc = subprocess.Popen(opts.argv)
  > time.sleep(opts.duration[0])
  > proc.poll()
  > if proc.returncode is None:
  >     proc.send_signal(sig)
  >     proc.wait()
  >     sys.exit(124)
  > EOF

Set up repository
  $ hg init repo
  $ cd repo
  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > sleepext = ../sleepext.py
  > EOF

Test ctrl-c
  $ python $TESTTMP/timeout.py -s INT 1 hg sleep 2
  interrupted!
  [124]

  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > nointerrupt = yes
  > EOF

  $ python $TESTTMP/timeout.py -s INT 1 hg sleep 2
  interrupted!
  [124]

  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > nointerrupt-interactiveonly = False
  > EOF

  $ python $TESTTMP/timeout.py -s INT 1 hg sleep 2
  shutting down cleanly
  press ^C again to terminate immediately (dangerous)
  end of unsafe operation
  interrupted!
  [124]