procutils: don't try to get `.buffer` if sys.stdin is None While hunting down following test failure of test-chg.t on Python 3, I stumbled the case when `.buffer` is not available as sys.stdin is None. --- /home/pulkit/repo/hg-committed/tests/test-chg.t +++ /home/pulkit/repo/hg-committed/tests/test-chg.t.err @@ -203,7 +203,31 @@ $ CHGDEBUG=1 chg version -q 0<&- chg: debug: * stdio fds are missing (glob) chg: debug: * execute original hg (glob) - Mercurial Distributed SCM * (glob) + Traceback (most recent call last): + File "/tmp/hgtests.avspvsq4/install/bin/hg", line 43, in <module> + dispatch.run() + File "/usr/lib/python3.6/importlib/util.py", line 233, in __getattribute__ + self.__spec__.loader.exec_module(self) + File "<frozen importlib._bootstrap_external>", line 678, in exec_module + File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed + File "/tmp/hgtests.avspvsq4/install/lib/python/mercurial/dispatch.py", line 726, in <module> + class lazyaliasentry(object): + File "/tmp/hgtests.avspvsq4/install/lib/python/mercurial/dispatch.py", line 737, in lazyaliasentry + @util.propertycache + File "/usr/lib/python3.6/importlib/util.py", line 233, in __getattribute__ + self.__spec__.loader.exec_module(self) + File "<frozen importlib._bootstrap_external>", line 678, in exec_module + File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed + File "/tmp/hgtests.avspvsq4/install/lib/python/mercurial/util.py", line 3473, in <module> + f=procutil.stderr, + File "/usr/lib/python3.6/importlib/util.py", line 233, in __getattribute__ + self.__spec__.loader.exec_module(self) + File "<frozen importlib._bootstrap_external>", line 678, in exec_module + File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed + File "/tmp/hgtests.avspvsq4/install/lib/python/mercurial/utils/procutil.py", line 127, in <module> + stdin = sys.stdin.buffer + AttributeError: 'NoneType' object has no attribute 'buffer' + [1] server lifecycle ---------------- Differential Revision: https://phab.mercurial-scm.org/D9500

# Read the output of a "svn log --xml" command on stdin, parse it and
# print a subset of attributes common to all svn versions tested by
# hg.
from __future__ import absolute_import
import sys
import xml.dom.minidom


def xmltext(e):
    return ''.join(c.data for c in e.childNodes if c.nodeType == c.TEXT_NODE)


def parseentry(entry):
    e = {}
    e['revision'] = entry.getAttribute('revision')
    e['author'] = xmltext(entry.getElementsByTagName('author')[0])
    e['msg'] = xmltext(entry.getElementsByTagName('msg')[0])
    e['paths'] = []
    paths = entry.getElementsByTagName('paths')
    if paths:
        paths = paths[0]
        for p in paths.getElementsByTagName('path'):
            action = p.getAttribute('action').encode('utf-8')
            path = xmltext(p).encode('utf-8')
            frompath = p.getAttribute('copyfrom-path').encode('utf-8')
            fromrev = p.getAttribute('copyfrom-rev').encode('utf-8')
            e['paths'].append((path, action, frompath, fromrev))
    return e


def parselog(data):
    entries = []
    doc = xml.dom.minidom.parseString(data)
    for e in doc.getElementsByTagName('logentry'):
        entries.append(parseentry(e))
    return entries


def printentries(entries):
    try:
        fp = sys.stdout.buffer
    except AttributeError:
        fp = sys.stdout
    for e in entries:
        for k in ('revision', 'author', 'msg'):
            fp.write(('%s: %s\n' % (k, e[k])).encode('utf-8'))
        for path, action, fpath, frev in sorted(e['paths']):
            frominfo = b''
            if frev:
                frominfo = b' (from %s@%s)' % (fpath, frev)
            p = b' %s %s%s\n' % (action, path, frominfo)
            fp.write(p)


if __name__ == '__main__':
    data = sys.stdin.read()
    entries = parselog(data)
    printentries(entries)