setdiscovery: return anyincoming=False when remote's only head is nullid
This fixes (issue2907) a crash when using 'hg incoming --bundle' with an empty
remote repo and a non-empty local repo.
This also fixes an unreported bug that 'hg summary --remote' erroneously
reports incoming changes when the remote repo is empty and the local is not.
Also, add a test to make sure issue2907 stays fixed
$ hg clone http://localhost:$HGPORT/ copy
abort: error: Connection refused
[255]
$ test -d copy || echo copy: No such file or directory
copy: No such file or directory
$ cat > dumb.py <<EOF
> import BaseHTTPServer, SimpleHTTPServer, os, signal
> def run(server_class=BaseHTTPServer.HTTPServer,
> handler_class=SimpleHTTPServer.SimpleHTTPRequestHandler):
> server_address = ('localhost', int(os.environ['HGPORT']))
> httpd = server_class(server_address, handler_class)
> httpd.serve_forever()
> signal.signal(signal.SIGTERM, lambda x: sys.exit(0))
> run()
> EOF
$ python dumb.py 2>/dev/null &
$ echo $! >> $DAEMON_PIDS
give the server some time to start running
$ sleep 1
$ hg clone http://localhost:$HGPORT/foo copy2 2>&1
abort: HTTP Error 404: * (glob)
[255]
$ kill $!