annotate contrib/debugcmdserver.py @ 45034:b1a1702262c9 stable

py3: fix crash when server address is 0.0.0.0 (issue6362)

`socket.getfqdn()` assumes that the name is passed as `str` on Python 3 and
always returns `str` in this case. Mercurial passed `bytes` (but still expected
a `str` result), which worked by chance in many cases, except for e.g.
b'0.0.0.0', which was returned unchanged, breaking later code.

Instead of calling `socket.getfqdn()`, we can also use `self.server_name` from
the base `HTTPServer` class, which already stores the FQDN of the locally-bound
socket name (see `BaseHTTPServer.py` in the Python 2 stdlib and
`http/server.py` in the Python 3 stdlib).

#!/usr/bin/env python
#
# Dumps output generated by Mercurial's command server in a formatted style to a
# given file or stderr if '-' is specified. Output is also written in its raw
# format to stdout.
#
# $ ./hg serve --cmds pipe | ./contrib/debugcmdserver.py -
# o, 52   -> 'capabilities: getencoding runcommand\nencoding: UTF-8'

from __future__ import absolute_import, print_function
import struct
import sys

if len(sys.argv) != 2:
    print('usage: debugcmdserver.py FILE')
    sys.exit(1)

outputfmt = '>cI'
outputfmtsize = struct.calcsize(outputfmt)

if sys.argv[1] == '-':
    log = sys.stderr
else:
    log = open(sys.argv[1], 'a')


def read(size):
    data = sys.stdin.read(size)
    if not data:
        raise EOFError
    sys.stdout.write(data)
    sys.stdout.flush()
    return data


try:
    while True:
        header = read(outputfmtsize)
        channel, length = struct.unpack(outputfmt, header)
        log.write('%s, %-4d' % (channel, length))
        if channel in 'IL':
            log.write(' -> waiting for input\n')
        else:
            data = read(length)
            log.write(' -> %r\n' % data)
        log.flush()
except EOFError:
    pass
finally:
    if log != sys.stderr:
        log.close()