tests/test-hgweb-non-interactive.t

chg: downgrade "failed to read channel" from abortmsg to debugmsg

If the server has an uncaught exception, it will exit without being able to
write the channel information. In this case, the client is likely to complain
about "failed to read channel", which looks inconsistent with original hg.
This patch silences the error message and makes uncaught exception behavior
more like original hg. It will help chg to pass test-fileset.t.

Tests if hgweb can run without touching sys.stdin, as is required
by the WSGI standard and strictly implemented by mod_wsgi.

  $ hg init repo
  $ cd repo
  $ echo foo > bar
  $ hg add bar
  $ hg commit -m "test"
  $ cat > request.py <<EOF
  > from mercurial import dispatch
  > from mercurial.hgweb.hgweb_mod import hgweb
  > from mercurial.ui import ui
  > from mercurial import hg
  > from StringIO import StringIO
  > import os, sys
  > 
  > class FileLike(object):
  >     def __init__(self, real):
  >         self.real = real
  >     def fileno(self):
  >         print >> sys.__stdout__, 'FILENO'
  >         return self.real.fileno()
  >     def read(self):
  >         print >> sys.__stdout__, 'READ'
  >         return self.real.read()
  >     def readline(self):
  >         print >> sys.__stdout__, 'READLINE'
  >         return self.real.readline()
  > 
  > sys.stdin = FileLike(sys.stdin)
  > errors = StringIO()
  > input = StringIO()
  > output = StringIO()
  > 
  > def startrsp(status, headers):
  >     print '---- STATUS'
  >     print status
  >     print '---- HEADERS'
  >     print [i for i in headers if i[0] != 'ETag']
  >     print '---- DATA'
  >     return output.write
  > 
  > env = {
  >     'wsgi.version': (1, 0),
  >     'wsgi.url_scheme': 'http',
  >     'wsgi.errors': errors,
  >     'wsgi.input': input,
  >     'wsgi.multithread': False,
  >     'wsgi.multiprocess': False,
  >     'wsgi.run_once': False,
  >     'REQUEST_METHOD': 'GET',
  >     'SCRIPT_NAME': '',
  >     'PATH_INFO': '',
  >     'QUERY_STRING': '',
  >     'SERVER_NAME': '127.0.0.1',
  >     'SERVER_PORT': os.environ['HGPORT'],
  >     'SERVER_PROTOCOL': 'HTTP/1.0'
  > }
  > 
  > i = hgweb('.')
  > for c in i(env, startrsp):
  >     pass
  > print '---- ERRORS'
  > print errors.getvalue()
  > print '---- OS.ENVIRON wsgi variables'
  > print sorted([x for x in os.environ if x.startswith('wsgi')])
  > print '---- request.ENVIRON wsgi variables'
  > with i._obtainrepo() as repo:
  >     print sorted([x for x in repo.ui.environ if x.startswith('wsgi')])
  > EOF
  $ python request.py
  ---- STATUS
  200 Script output follows
  ---- HEADERS
  [('Content-Type', 'text/html; charset=ascii')]
  ---- DATA
  ---- ERRORS
  
  ---- OS.ENVIRON wsgi variables
  []
  ---- request.ENVIRON wsgi variables
  ['wsgi.errors', 'wsgi.input', 'wsgi.multiprocess', 'wsgi.multithread', 'wsgi.run_once', 'wsgi.url_scheme', 'wsgi.version']

  $ cd ..