test-commandserver: allow check() to make connection in different way

The next patch will add connector for 'unix' mode server.

contrib/hgclient.py

@@ -1,72 +1,72 b''
 # A minimal client for Mercurial's command server
 
 import sys, struct, subprocess, cStringIO
 
-def connect(path=None):
+def connectpipe(path=None):
     cmdline = ['hg', 'serve', '--cmdserver', 'pipe']
     if path:
         cmdline += ['-R', path]
 
     server = subprocess.Popen(cmdline, stdin=subprocess.PIPE,
                               stdout=subprocess.PIPE)
 
     return server
 
 def writeblock(server, data):
     server.stdin.write(struct.pack('>I', len(data)))
     server.stdin.write(data)
     server.stdin.flush()
 
 def readchannel(server):
     data = server.stdout.read(5)
     if not data:
         raise EOFError
     channel, length = struct.unpack('>cI', data)
     if channel in 'IL':
         return channel, length
     else:
         return channel, server.stdout.read(length)
 
 def sep(text):
     return text.replace('\\', '/')
 
 def runcommand(server, args, output=sys.stdout, error=sys.stderr, input=None,
                outfilter=lambda x: x):
     print '*** runcommand', ' '.join(args)
     sys.stdout.flush()
     server.stdin.write('runcommand\n')
     writeblock(server, '\0'.join(args))
 
     if not input:
         input = cStringIO.StringIO()
 
     while True:
         ch, data = readchannel(server)
         if ch == 'o':
             output.write(outfilter(data))
             output.flush()
         elif ch == 'e':
             error.write(data)
             error.flush()
         elif ch == 'I':
             writeblock(server, input.read(data))
         elif ch == 'L':
             writeblock(server, input.readline(data))
         elif ch == 'r':
             ret, = struct.unpack('>i', data)
             if ret != 0:
                 print ' [%d]' % ret
             return ret
         else:
             print "unexpected channel %c: %r" % (ch, data)
             if ch.isupper():
                 return
 
-def check(func):
+def check(func, connect=connectpipe):
     sys.stdout.flush()
     server = connect()
     try:
         return func(server)
     finally:
         server.stdin.close()
         server.wait()