ui: look before you leap on sys.stderr.closed (and look nicer)

f83291e5643e introduced a fix if sys.stdout.closed does not exist.

This change uses a getattr with default instead of hasattr (which just calls
getattr) and accessing the attribute.

Additionally it applies the same fix for sys.stderr.closed as this is not
available in the bpython shell (reported by Roger Gammans).

mercurial/ui.py

@@ -1,403 +1,403 b''
 # ui.py - user interface bits for mercurial
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from i18n import _
 import errno, getpass, os, socket, sys, tempfile, traceback
 import config, util, error
 
 _booleans = {'1': True, 'yes': True, 'true': True, 'on': True,
              '0': False, 'no': False, 'false': False, 'off': False}
 
 class ui(object):
     def __init__(self, src=None):
         self._buffers = []
         self.quiet = self.verbose = self.debugflag = self.tracebackflag = False
         self._reportuntrusted = True
         self._ocfg = config.config() # overlay
         self._tcfg = config.config() # trusted
         self._ucfg = config.config() # untrusted
         self._trustusers = set()
         self._trustgroups = set()
 
         if src:
             self._tcfg = src._tcfg.copy()
             self._ucfg = src._ucfg.copy()
             self._ocfg = src._ocfg.copy()
             self._trustusers = src._trustusers.copy()
             self._trustgroups = src._trustgroups.copy()
             self.environ = src.environ
             self.fixconfig()
         else:
             # shared read-only environment
             self.environ = os.environ
             # we always trust global config files
             for f in util.rcpath():
                 self.readconfig(f, trust=True)
 
     def copy(self):
         return self.__class__(self)
 
     def _is_trusted(self, fp, f):
         st = util.fstat(fp)
         if util.isowner(st):
             return True
 
         tusers, tgroups = self._trustusers, self._trustgroups
         if '*' in tusers or '*' in tgroups:
             return True
 
         user = util.username(st.st_uid)
         group = util.groupname(st.st_gid)
         if user in tusers or group in tgroups or user == util.username():
             return True
 
         if self._reportuntrusted:
             self.warn(_('Not trusting file %s from untrusted '
                         'user %s, group %s\n') % (f, user, group))
         return False
 
     def readconfig(self, filename, root=None, trust=False,
                    sections=None, remap=None):
         try:
             fp = open(filename)
         except IOError:
             if not sections: # ignore unless we were looking for something
                 return
             raise
 
         cfg = config.config()
         trusted = sections or trust or self._is_trusted(fp, filename)
 
         try:
             cfg.read(filename, fp, sections=sections, remap=remap)
         except error.ConfigError, inst:
             if trusted:
                 raise
             self.warn(_("Ignored: %s\n") % str(inst))
 
         if trusted:
             self._tcfg.update(cfg)
             self._tcfg.update(self._ocfg)
         self._ucfg.update(cfg)
         self._ucfg.update(self._ocfg)
 
         if root is None:
             root = os.path.expanduser('~')
         self.fixconfig(root=root)
 
     def fixconfig(self, root=None):
         # translate paths relative to root (or home) into absolute paths
         root = root or os.getcwd()
         for c in self._tcfg, self._ucfg, self._ocfg:
             for n, p in c.items('paths'):
                 if p and "://" not in p and not os.path.isabs(p):
                     c.set("paths", n, os.path.normpath(os.path.join(root, p)))
 
         # update ui options
         self.debugflag = self.configbool('ui', 'debug')
         self.verbose = self.debugflag or self.configbool('ui', 'verbose')
         self.quiet = not self.debugflag and self.configbool('ui', 'quiet')
         if self.verbose and self.quiet:
             self.quiet = self.verbose = False
         self._reportuntrusted = self.configbool("ui", "report_untrusted", True)
         self.tracebackflag = self.configbool('ui', 'traceback', False)
 
         # update trust information
         self._trustusers.update(self.configlist('trusted', 'users'))
         self._trustgroups.update(self.configlist('trusted', 'groups'))
 
     def setconfig(self, section, name, value):
         for cfg in (self._ocfg, self._tcfg, self._ucfg):
             cfg.set(section, name, value)
         self.fixconfig()
 
     def _data(self, untrusted):
         return untrusted and self._ucfg or self._tcfg
 
     def configsource(self, section, name, untrusted=False):
         return self._data(untrusted).source(section, name) or 'none'
 
     def config(self, section, name, default=None, untrusted=False):
         value = self._data(untrusted).get(section, name, default)
         if self.debugflag and not untrusted and self._reportuntrusted:
             uvalue = self._ucfg.get(section, name)
             if uvalue is not None and uvalue != value:
                 self.debug(_("ignoring untrusted configuration option "
                              "%s.%s = %s\n") % (section, name, uvalue))
         return value
 
     def configbool(self, section, name, default=False, untrusted=False):
         v = self.config(section, name, None, untrusted)
         if v is None:
             return default
         if isinstance(v, bool):
             return v
         if v.lower() not in _booleans:
             raise error.ConfigError(_("%s.%s not a boolean ('%s')")
                                     % (section, name, v))
         return _booleans[v.lower()]
 
     def configlist(self, section, name, default=None, untrusted=False):
         """Return a list of comma/space separated strings"""
         result = self.config(section, name, untrusted=untrusted)
         if result is None:
             result = default or []
         if isinstance(result, basestring):
             result = result.replace(",", " ").split()
         return result
 
     def has_section(self, section, untrusted=False):
         '''tell whether section exists in config.'''
         return section in self._data(untrusted)
 
     def configitems(self, section, untrusted=False):
         items = self._data(untrusted).items(section)
         if self.debugflag and not untrusted and self._reportuntrusted:
             for k, v in self._ucfg.items(section):
                 if self._tcfg.get(section, k) != v:
                     self.debug(_("ignoring untrusted configuration option "
                                 "%s.%s = %s\n") % (section, k, v))
         return items
 
     def walkconfig(self, untrusted=False):
         cfg = self._data(untrusted)
         for section in cfg.sections():
             for name, value in self.configitems(section, untrusted):
                 yield section, name, str(value).replace('\n', '\\n')
 
     def username(self):
         """Return default username to be used in commits.
 
         Searched in this order: $HGUSER, [ui] section of hgrcs, $EMAIL
         and stop searching if one of these is set.
         If not found and ui.askusername is True, ask the user, else use
         ($LOGNAME or $USER or $LNAME or $USERNAME) + "@full.hostname".
         """
         user = os.environ.get("HGUSER")
         if user is None:
             user = self.config("ui", "username")
         if user is None:
             user = os.environ.get("EMAIL")
         if user is None and self.configbool("ui", "askusername"):
             user = self.prompt(_("enter a commit username:"), default=None)
         if user is None and not self.interactive():
             try:
                 user = '%s@%s' % (util.getuser(), socket.getfqdn())
                 self.warn(_("No username found, using '%s' instead\n") % user)
             except KeyError:
                 pass
         if not user:
             raise util.Abort(_('no username supplied (see "hg help config")'))
         if "\n" in user:
             raise util.Abort(_("username %s contains a newline\n") % repr(user))
         return user
 
     def shortuser(self, user):
         """Return a short representation of a user name or email address."""
         if not self.verbose:
             user = util.shortuser(user)
         return user
 
     def _path(self, loc):
         p = self.config('paths', loc)
         if p:
             if '%%' in p:
                 self.warn("(deprecated '%%' in path %s=%s from %s)\n" %
                           (loc, p, self.configsource('paths', loc)))
                 p = p.replace('%%', '%')
             p = util.expandpath(p)
         return p
 
     def expandpath(self, loc, default=None):
         """Return repository location relative to cwd or from [paths]"""
         if "://" in loc or os.path.isdir(os.path.join(loc, '.hg')):
             return loc
 
         path = self._path(loc)
         if not path and default is not None:
             path = self._path(default)
         return path or loc
 
     def pushbuffer(self):
         self._buffers.append([])
 
     def popbuffer(self):
         return "".join(self._buffers.pop())
 
     def write(self, *args):
         if self._buffers:
             self._buffers[-1].extend([str(a) for a in args])
         else:
             for a in args:
                 sys.stdout.write(str(a))
 
     def write_err(self, *args):
         try:
-            if not hasattr(sys.stdout, 'closed') or not sys.stdout.closed:
+            if not getattr(sys.stdout, 'closed', False):
                 sys.stdout.flush()
             for a in args:
                 sys.stderr.write(str(a))
             # stderr may be buffered under win32 when redirected to files,
             # including stdout.
-            if not sys.stderr.closed:
+            if not getattr(sys.stderr, 'closed', False):
                 sys.stderr.flush()
         except IOError, inst:
             if inst.errno != errno.EPIPE:
                 raise
 
     def flush(self):
         try: sys.stdout.flush()
         except: pass
         try: sys.stderr.flush()
         except: pass
 
     def interactive(self):
         i = self.configbool("ui", "interactive", None)
         if i is None:
             try:
                 return sys.stdin.isatty()
             except AttributeError:
                 # some environments replace stdin without implementing isatty
                 # usually those are non-interactive
                 return False
 
         return i
 
     def _readline(self, prompt=''):
         if sys.stdin.isatty():
             try:
                 # magically add command line editing support, where
                 # available
                 import readline
                 # force demandimport to really load the module
                 readline.read_history_file
                 # windows sometimes raises something other than ImportError
             except Exception:
                 pass
         line = raw_input(prompt)
         # When stdin is in binary mode on Windows, it can cause
         # raw_input() to emit an extra trailing carriage return
         if os.linesep == '\r\n' and line and line[-1] == '\r':
             line = line[:-1]
         return line
 
     def prompt(self, msg, default="y"):
         """Prompt user with msg, read response.
         If ui is not interactive, the default is returned.
         """
         if not self.interactive():
             self.write(msg, ' ', default, "\n")
             return default
         try:
             r = self._readline(msg + ' ')
             if not r:
                 return default
             return r
         except EOFError:
             raise util.Abort(_('response expected'))
 
     def promptchoice(self, msg, choices, default=0):
         """Prompt user with msg, read response, and ensure it matches
         one of the provided choices. The index of the choice is returned.
         choices is a sequence of acceptable responses with the format:
         ('&None', 'E&xec', 'Sym&link') Responses are case insensitive.
         If ui is not interactive, the default is returned.
         """
         resps = [s[s.index('&')+1].lower() for s in choices]
         while True:
             r = self.prompt(msg, resps[default])
             if r.lower() in resps:
                 return resps.index(r.lower())
             self.write(_("unrecognized response\n"))
 
     def getpass(self, prompt=None, default=None):
         if not self.interactive():
             return default
         try:
             return getpass.getpass(prompt or _('password: '))
         except EOFError:
             raise util.Abort(_('response expected'))
     def status(self, *msg):
         if not self.quiet:
             self.write(*msg)
     def warn(self, *msg):
         self.write_err(*msg)
     def note(self, *msg):
         if self.verbose:
             self.write(*msg)
     def debug(self, *msg):
         if self.debugflag:
             self.write(*msg)
     def edit(self, text, user):
         (fd, name) = tempfile.mkstemp(prefix="hg-editor-", suffix=".txt",
                                       text=True)
         try:
             f = os.fdopen(fd, "w")
             f.write(text)
             f.close()
 
             editor = self.geteditor()
 
             util.system("%s \"%s\"" % (editor, name),
                         environ={'HGUSER': user},
                         onerr=util.Abort, errprefix=_("edit failed"))
 
             f = open(name)
             t = f.read()
             f.close()
         finally:
             os.unlink(name)
 
         return t
 
     def traceback(self, exc=None):
         '''print exception traceback if traceback printing enabled.
         only to call in exception handler. returns true if traceback
         printed.'''
         if self.tracebackflag:
             if exc:
                 traceback.print_exception(exc[0], exc[1], exc[2])
             else:
                 traceback.print_exc()
         return self.tracebackflag
 
     def geteditor(self):
         '''return editor to use'''
         return (os.environ.get("HGEDITOR") or
                 self.config("ui", "editor") or
                 os.environ.get("VISUAL") or
                 os.environ.get("EDITOR", "vi"))
 
     def progress(self, topic, pos, item="", unit="", total=None):
         '''show a progress message
 
         With stock hg, this is simply a debug message that is hidden
         by default, but with extensions or GUI tools it may be
         visible. 'topic' is the current operation, 'item' is a
         non-numeric marker of the current position (ie the currently
         in-process file), 'pos' is the current numeric position (ie
         revision, bytes, etc.), unit is a corresponding unit label,
         and total is the highest expected pos.
 
         Multiple nested topics may be active at a time. All topics
         should be marked closed by setting pos to None at termination.
         '''
 
         if pos == None or not self.debugflag:
             return
 
         if unit:
             unit = ' ' + unit
         if item:
             item = ' ' + item
 
         if total:
             pct = 100.0 * pos / total
             self.debug('%s:%s %s/%s%s (%4.2f%%)\n'
                      % (topic, item, pos, total, unit, pct))
         else:
             self.debug('%s:%s %s%s\n' % (topic, item, pos, unit))