dispatch: defer environment variable resolution in alias commands (BC)

Before this patch, if there are environment variables in an alias command,
they will be expanded immediately when we first see the alias.

This will cause issues with chg, because environment variable updates will
not propagate to expanded arguments.

This patch makes "args" of "cmdalias" a property that will be calculated
every time when accessed.

mercurial/dispatch.py

@@ -1,1084 +1,1088 b''
 # dispatch.py - command dispatching 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 __future__ import absolute_import, print_function
 
 import atexit
 import difflib
 import errno
 import os
 import pdb
 import re
 import shlex
 import signal
 import socket
 import sys
 import time
 import traceback
 
 
 from .i18n import _
 
 from . import (
     cmdutil,
     commands,
     demandimport,
     encoding,
     error,
     extensions,
     fancyopts,
     fileset,
     hg,
     hook,
     revset,
     templatefilters,
     templatekw,
     templater,
     ui as uimod,
     util,
 )
 
 class request(object):
     def __init__(self, args, ui=None, repo=None, fin=None, fout=None,
                  ferr=None):
         self.args = args
         self.ui = ui
         self.repo = repo
 
         # input/output/error streams
         self.fin = fin
         self.fout = fout
         self.ferr = ferr
 
 def run():
     "run the command in sys.argv"
     sys.exit((dispatch(request(sys.argv[1:])) or 0) & 255)
 
 def _getsimilar(symbols, value):
     sim = lambda x: difflib.SequenceMatcher(None, value, x).ratio()
     # The cutoff for similarity here is pretty arbitrary. It should
     # probably be investigated and tweaked.
     return [s for s in symbols if sim(s) > 0.6]
 
 def _reportsimilar(write, similar):
     if len(similar) == 1:
         write(_("(did you mean %s?)\n") % similar[0])
     elif similar:
         ss = ", ".join(sorted(similar))
         write(_("(did you mean one of %s?)\n") % ss)
 
 def _formatparse(write, inst):
     similar = []
     if isinstance(inst, error.UnknownIdentifier):
         # make sure to check fileset first, as revset can invoke fileset
         similar = _getsimilar(inst.symbols, inst.function)
     if len(inst.args) > 1:
         write(_("hg: parse error at %s: %s\n") %
                          (inst.args[1], inst.args[0]))
         if (inst.args[0][0] == ' '):
             write(_("unexpected leading whitespace\n"))
     else:
         write(_("hg: parse error: %s\n") % inst.args[0])
         _reportsimilar(write, similar)
     if inst.hint:
         write(_("(%s)\n") % inst.hint)
 
 def dispatch(req):
     "run the command specified in req.args"
     if req.ferr:
         ferr = req.ferr
     elif req.ui:
         ferr = req.ui.ferr
     else:
         ferr = sys.stderr
 
     try:
         if not req.ui:
             req.ui = uimod.ui()
         if '--traceback' in req.args:
             req.ui.setconfig('ui', 'traceback', 'on', '--traceback')
 
         # set ui streams from the request
         if req.fin:
             req.ui.fin = req.fin
         if req.fout:
             req.ui.fout = req.fout
         if req.ferr:
             req.ui.ferr = req.ferr
     except error.Abort as inst:
         ferr.write(_("abort: %s\n") % inst)
         if inst.hint:
             ferr.write(_("(%s)\n") % inst.hint)
         return -1
     except error.ParseError as inst:
         _formatparse(ferr.write, inst)
         return -1
 
     msg = ' '.join(' ' in a and repr(a) or a for a in req.args)
     starttime = time.time()
     ret = None
     try:
         ret = _runcatch(req)
     except KeyboardInterrupt:
         try:
             req.ui.warn(_("interrupted!\n"))
         except IOError as inst:
             if inst.errno != errno.EPIPE:
                 raise
         ret = -1
     finally:
         duration = time.time() - starttime
         req.ui.flush()
         req.ui.log("commandfinish", "%s exited %s after %0.2f seconds\n",
                    msg, ret or 0, duration)
     return ret
 
 def _runcatch(req):
     def catchterm(*args):
         raise error.SignalInterrupt
 
     ui = req.ui
     try:
         for name in 'SIGBREAK', 'SIGHUP', 'SIGTERM':
             num = getattr(signal, name, None)
             if num:
                 signal.signal(num, catchterm)
     except ValueError:
         pass # happens if called in a thread
 
     try:
         try:
             debugger = 'pdb'
             debugtrace = {
                 'pdb' : pdb.set_trace
             }
             debugmortem = {
                 'pdb' : pdb.post_mortem
             }
 
             # read --config before doing anything else
             # (e.g. to change trust settings for reading .hg/hgrc)
             cfgs = _parseconfig(req.ui, _earlygetopt(['--config'], req.args))
 
             if req.repo:
                 # copy configs that were passed on the cmdline (--config) to
                 # the repo ui
                 for sec, name, val in cfgs:
                     req.repo.ui.setconfig(sec, name, val, source='--config')
 
             # developer config: ui.debugger
             debugger = ui.config("ui", "debugger")
             debugmod = pdb
             if not debugger or ui.plain():
                 # if we are in HGPLAIN mode, then disable custom debugging
                 debugger = 'pdb'
             elif '--debugger' in req.args:
                 # This import can be slow for fancy debuggers, so only
                 # do it when absolutely necessary, i.e. when actual
                 # debugging has been requested
                 with demandimport.deactivated():
                     try:
                         debugmod = __import__(debugger)
                     except ImportError:
                         pass # Leave debugmod = pdb
 
             debugtrace[debugger] = debugmod.set_trace
             debugmortem[debugger] = debugmod.post_mortem
 
             # enter the debugger before command execution
             if '--debugger' in req.args:
                 ui.warn(_("entering debugger - "
                         "type c to continue starting hg or h for help\n"))
 
                 if (debugger != 'pdb' and
                     debugtrace[debugger] == debugtrace['pdb']):
                     ui.warn(_("%s debugger specified "
                               "but its module was not found\n") % debugger)
                 with demandimport.deactivated():
                     debugtrace[debugger]()
             try:
                 return _dispatch(req)
             finally:
                 ui.flush()
         except: # re-raises
             # enter the debugger when we hit an exception
             if '--debugger' in req.args:
                 traceback.print_exc()
                 debugmortem[debugger](sys.exc_info()[2])
             ui.traceback()
             raise
 
     # Global exception handling, alphabetically
     # Mercurial-specific first, followed by built-in and library exceptions
     except error.AmbiguousCommand as inst:
         ui.warn(_("hg: command '%s' is ambiguous:\n    %s\n") %
                 (inst.args[0], " ".join(inst.args[1])))
     except error.ParseError as inst:
         _formatparse(ui.warn, inst)
         return -1
     except error.LockHeld as inst:
         if inst.errno == errno.ETIMEDOUT:
             reason = _('timed out waiting for lock held by %s') % inst.locker
         else:
             reason = _('lock held by %s') % inst.locker
         ui.warn(_("abort: %s: %s\n") % (inst.desc or inst.filename, reason))
     except error.LockUnavailable as inst:
         ui.warn(_("abort: could not lock %s: %s\n") %
                (inst.desc or inst.filename, inst.strerror))
     except error.CommandError as inst:
         if inst.args[0]:
             ui.warn(_("hg %s: %s\n") % (inst.args[0], inst.args[1]))
             commands.help_(ui, inst.args[0], full=False, command=True)
         else:
             ui.warn(_("hg: %s\n") % inst.args[1])
             commands.help_(ui, 'shortlist')
     except error.OutOfBandError as inst:
         if inst.args:
             msg = _("abort: remote error:\n")
         else:
             msg = _("abort: remote error\n")
         ui.warn(msg)
         if inst.args:
             ui.warn(''.join(inst.args))
         if inst.hint:
             ui.warn('(%s)\n' % inst.hint)
     except error.RepoError as inst:
         ui.warn(_("abort: %s!\n") % inst)
         if inst.hint:
             ui.warn(_("(%s)\n") % inst.hint)
     except error.ResponseError as inst:
         ui.warn(_("abort: %s") % inst.args[0])
         if not isinstance(inst.args[1], basestring):
             ui.warn(" %r\n" % (inst.args[1],))
         elif not inst.args[1]:
             ui.warn(_(" empty string\n"))
         else:
             ui.warn("\n%r\n" % util.ellipsis(inst.args[1]))
     except error.CensoredNodeError as inst:
         ui.warn(_("abort: file censored %s!\n") % inst)
     except error.RevlogError as inst:
         ui.warn(_("abort: %s!\n") % inst)
     except error.SignalInterrupt:
         ui.warn(_("killed!\n"))
     except error.UnknownCommand as inst:
         ui.warn(_("hg: unknown command '%s'\n") % inst.args[0])
         try:
             # check if the command is in a disabled extension
             # (but don't check for extensions themselves)
             commands.help_(ui, inst.args[0], unknowncmd=True)
         except (error.UnknownCommand, error.Abort):
             suggested = False
             if len(inst.args) == 2:
                 sim = _getsimilar(inst.args[1], inst.args[0])
                 if sim:
                     _reportsimilar(ui.warn, sim)
                     suggested = True
             if not suggested:
                 commands.help_(ui, 'shortlist')
     except error.InterventionRequired as inst:
         ui.warn("%s\n" % inst)
         if inst.hint:
             ui.warn(_("(%s)\n") % inst.hint)
         return 1
     except error.Abort as inst:
         ui.warn(_("abort: %s\n") % inst)
         if inst.hint:
             ui.warn(_("(%s)\n") % inst.hint)
     except ImportError as inst:
         ui.warn(_("abort: %s!\n") % inst)
         m = str(inst).split()[-1]
         if m in "mpatch bdiff".split():
             ui.warn(_("(did you forget to compile extensions?)\n"))
         elif m in "zlib".split():
             ui.warn(_("(is your Python install correct?)\n"))
     except IOError as inst:
         if util.safehasattr(inst, "code"):
             ui.warn(_("abort: %s\n") % inst)
         elif util.safehasattr(inst, "reason"):
             try: # usually it is in the form (errno, strerror)
                 reason = inst.reason.args[1]
             except (AttributeError, IndexError):
                 # it might be anything, for example a string
                 reason = inst.reason
             if isinstance(reason, unicode):
                 # SSLError of Python 2.7.9 contains a unicode
                 reason = reason.encode(encoding.encoding, 'replace')
             ui.warn(_("abort: error: %s\n") % reason)
         elif (util.safehasattr(inst, "args")
               and inst.args and inst.args[0] == errno.EPIPE):
             pass
         elif getattr(inst, "strerror", None):
             if getattr(inst, "filename", None):
                 ui.warn(_("abort: %s: %s\n") % (inst.strerror, inst.filename))
             else:
                 ui.warn(_("abort: %s\n") % inst.strerror)
         else:
             raise
     except OSError as inst:
         if getattr(inst, "filename", None) is not None:
             ui.warn(_("abort: %s: '%s'\n") % (inst.strerror, inst.filename))
         else:
             ui.warn(_("abort: %s\n") % inst.strerror)
     except KeyboardInterrupt:
         raise
     except MemoryError:
         ui.warn(_("abort: out of memory\n"))
     except SystemExit as inst:
         # Commands shouldn't sys.exit directly, but give a return code.
         # Just in case catch this and and pass exit code to caller.
         return inst.code
     except socket.error as inst:
         ui.warn(_("abort: %s\n") % inst.args[-1])
     except:  # perhaps re-raises
         if not handlecommandexception(ui):
             raise
 
     return -1
 
 def aliasargs(fn, givenargs):
     args = getattr(fn, 'args', [])
     if args:
         cmd = ' '.join(map(util.shellquote, args))
 
         nums = []
         def replacer(m):
             num = int(m.group(1)) - 1
             nums.append(num)
             if num < len(givenargs):
                 return givenargs[num]
             raise error.Abort(_('too few arguments for command alias'))
         cmd = re.sub(r'\$(\d+|\$)', replacer, cmd)
         givenargs = [x for i, x in enumerate(givenargs)
                      if i not in nums]
         args = shlex.split(cmd)
     return args + givenargs
 
 def aliasinterpolate(name, args, cmd):
     '''interpolate args into cmd for shell aliases
 
     This also handles $0, $@ and "$@".
     '''
     # util.interpolate can't deal with "$@" (with quotes) because it's only
     # built to match prefix + patterns.
     replacemap = dict(('$%d' % (i + 1), arg) for i, arg in enumerate(args))
     replacemap['$0'] = name
     replacemap['$$'] = '$'
     replacemap['$@'] = ' '.join(args)
     # Typical Unix shells interpolate "$@" (with quotes) as all the positional
     # parameters, separated out into words. Emulate the same behavior here by
     # quoting the arguments individually. POSIX shells will then typically
     # tokenize each argument into exactly one word.
     replacemap['"$@"'] = ' '.join(util.shellquote(arg) for arg in args)
     # escape '\$' for regex
     regex = '|'.join(replacemap.keys()).replace('$', r'\$')
     r = re.compile(regex)
     return r.sub(lambda x: replacemap[x.group()], cmd)
 
 class cmdalias(object):
     def __init__(self, name, definition, cmdtable, source):
         self.name = self.cmd = name
         self.cmdname = ''
         self.definition = definition
         self.fn = None
-        self.args = []
+        self.givenargs = []
         self.opts = []
         self.help = ''
         self.badalias = None
         self.unknowncmd = False
         self.source = source
 
         try:
             aliases, entry = cmdutil.findcmd(self.name, cmdtable)
             for alias, e in cmdtable.iteritems():
                 if e is entry:
                     self.cmd = alias
                     break
             self.shadows = True
         except error.UnknownCommand:
             self.shadows = False
 
         if not self.definition:
             self.badalias = _("no definition for alias '%s'") % self.name
             return
 
         if self.definition.startswith('!'):
             self.shell = True
             def fn(ui, *args):
                 env = {'HG_ARGS': ' '.join((self.name,) + args)}
                 def _checkvar(m):
                     if m.groups()[0] == '$':
                         return m.group()
                     elif int(m.groups()[0]) <= len(args):
                         return m.group()
                     else:
                         ui.debug("No argument found for substitution "
                                  "of %i variable in alias '%s' definition."
                                  % (int(m.groups()[0]), self.name))
                         return ''
                 cmd = re.sub(r'\$(\d+|\$)', _checkvar, self.definition[1:])
                 cmd = aliasinterpolate(self.name, args, cmd)
                 return ui.system(cmd, environ=env)
             self.fn = fn
             return
 
         try:
             args = shlex.split(self.definition)
         except ValueError as inst:
             self.badalias = (_("error in definition for alias '%s': %s")
                              % (self.name, inst))
             return
         self.cmdname = cmd = args.pop(0)
-        args = map(util.expandpath, args)
+        self.givenargs = args
 
         for invalidarg in ("--cwd", "-R", "--repository", "--repo", "--config"):
             if _earlygetopt([invalidarg], args):
                 self.badalias = (_("error in definition for alias '%s': %s may "
                                    "only be given on the command line")
                                  % (self.name, invalidarg))
                 return
 
         try:
             tableentry = cmdutil.findcmd(cmd, cmdtable, False)[1]
             if len(tableentry) > 2:
                 self.fn, self.opts, self.help = tableentry
             else:
                 self.fn, self.opts = tableentry
 
-            self.args = aliasargs(self.fn, args)
             if self.help.startswith("hg " + cmd):
                 # drop prefix in old-style help lines so hg shows the alias
                 self.help = self.help[4 + len(cmd):]
             self.__doc__ = self.fn.__doc__
 
         except error.UnknownCommand:
             self.badalias = (_("alias '%s' resolves to unknown command '%s'")
                              % (self.name, cmd))
             self.unknowncmd = True
         except error.AmbiguousCommand:
             self.badalias = (_("alias '%s' resolves to ambiguous command '%s'")
                              % (self.name, cmd))
 
+    @property
+    def args(self):
+        args = map(util.expandpath, self.givenargs)
+        return aliasargs(self.fn, args)
+
     def __getattr__(self, name):
         adefaults = {'norepo': True, 'optionalrepo': False, 'inferrepo': False}
         if name not in adefaults:
             raise AttributeError(name)
         if self.badalias or util.safehasattr(self, 'shell'):
             return adefaults[name]
         return getattr(self.fn, name)
 
     def __call__(self, ui, *args, **opts):
         if self.badalias:
             hint = None
             if self.unknowncmd:
                 try:
                     # check if the command is in a disabled extension
                     cmd, ext = extensions.disabledcmd(ui, self.cmdname)[:2]
                     hint = _("'%s' is provided by '%s' extension") % (cmd, ext)
                 except error.UnknownCommand:
                     pass
             raise error.Abort(self.badalias, hint=hint)
         if self.shadows:
             ui.debug("alias '%s' shadows command '%s'\n" %
                      (self.name, self.cmdname))
 
         if util.safehasattr(self, 'shell'):
             return self.fn(ui, *args, **opts)
         else:
             try:
                 return util.checksignature(self.fn)(ui, *args, **opts)
             except error.SignatureError:
                 args = ' '.join([self.cmdname] + self.args)
                 ui.debug("alias '%s' expands to '%s'\n" % (self.name, args))
                 raise
 
 def addaliases(ui, cmdtable):
     # aliases are processed after extensions have been loaded, so they
     # may use extension commands. Aliases can also use other alias definitions,
     # but only if they have been defined prior to the current definition.
     for alias, definition in ui.configitems('alias'):
         source = ui.configsource('alias', alias)
         aliasdef = cmdalias(alias, definition, cmdtable, source)
 
         try:
             olddef = cmdtable[aliasdef.cmd][0]
             if olddef.definition == aliasdef.definition:
                 continue
         except (KeyError, AttributeError):
             # definition might not exist or it might not be a cmdalias
             pass
 
         cmdtable[aliasdef.name] = (aliasdef, aliasdef.opts, aliasdef.help)
 
 def _parse(ui, args):
     options = {}
     cmdoptions = {}
 
     try:
         args = fancyopts.fancyopts(args, commands.globalopts, options)
     except fancyopts.getopt.GetoptError as inst:
         raise error.CommandError(None, inst)
 
     if args:
         cmd, args = args[0], args[1:]
         aliases, entry = cmdutil.findcmd(cmd, commands.table,
                                          ui.configbool("ui", "strict"))
         cmd = aliases[0]
         args = aliasargs(entry[0], args)
         defaults = ui.config("defaults", cmd)
         if defaults:
             args = map(util.expandpath, shlex.split(defaults)) + args
         c = list(entry[1])
     else:
         cmd = None
         c = []
 
     # combine global options into local
     for o in commands.globalopts:
         c.append((o[0], o[1], options[o[1]], o[3]))
 
     try:
         args = fancyopts.fancyopts(args, c, cmdoptions, True)
     except fancyopts.getopt.GetoptError as inst:
         raise error.CommandError(cmd, inst)
 
     # separate global options back out
     for o in commands.globalopts:
         n = o[1]
         options[n] = cmdoptions[n]
         del cmdoptions[n]
 
     return (cmd, cmd and entry[0] or None, args, options, cmdoptions)
 
 def _parseconfig(ui, config):
     """parse the --config options from the command line"""
     configs = []
 
     for cfg in config:
         try:
             name, value = [cfgelem.strip()
                            for cfgelem in cfg.split('=', 1)]
             section, name = name.split('.', 1)
             if not section or not name:
                 raise IndexError
             ui.setconfig(section, name, value, '--config')
             configs.append((section, name, value))
         except (IndexError, ValueError):
             raise error.Abort(_('malformed --config option: %r '
                                '(use --config section.name=value)') % cfg)
 
     return configs
 
 def _earlygetopt(aliases, args):
     """Return list of values for an option (or aliases).
 
     The values are listed in the order they appear in args.
     The options and values are removed from args.
 
     >>> args = ['x', '--cwd', 'foo', 'y']
     >>> _earlygetopt(['--cwd'], args), args
     (['foo'], ['x', 'y'])
 
     >>> args = ['x', '--cwd=bar', 'y']
     >>> _earlygetopt(['--cwd'], args), args
     (['bar'], ['x', 'y'])
 
     >>> args = ['x', '-R', 'foo', 'y']
     >>> _earlygetopt(['-R'], args), args
     (['foo'], ['x', 'y'])
 
     >>> args = ['x', '-Rbar', 'y']
     >>> _earlygetopt(['-R'], args), args
     (['bar'], ['x', 'y'])
     """
     try:
         argcount = args.index("--")
     except ValueError:
         argcount = len(args)
     shortopts = [opt for opt in aliases if len(opt) == 2]
     values = []
     pos = 0
     while pos < argcount:
         fullarg = arg = args[pos]
         equals = arg.find('=')
         if equals > -1:
             arg = arg[:equals]
         if arg in aliases:
             del args[pos]
             if equals > -1:
                 values.append(fullarg[equals + 1:])
                 argcount -= 1
             else:
                 if pos + 1 >= argcount:
                     # ignore and let getopt report an error if there is no value
                     break
                 values.append(args.pop(pos))
                 argcount -= 2
         elif arg[:2] in shortopts:
             # short option can have no following space, e.g. hg log -Rfoo
             values.append(args.pop(pos)[2:])
             argcount -= 1
         else:
             pos += 1
     return values
 
 def runcommand(lui, repo, cmd, fullargs, ui, options, d, cmdpats, cmdoptions):
     # run pre-hook, and abort if it fails
     hook.hook(lui, repo, "pre-%s" % cmd, True, args=" ".join(fullargs),
               pats=cmdpats, opts=cmdoptions)
     ret = _runcommand(ui, options, cmd, d)
     # run post-hook, passing command result
     hook.hook(lui, repo, "post-%s" % cmd, False, args=" ".join(fullargs),
               result=ret, pats=cmdpats, opts=cmdoptions)
     return ret
 
 def _getlocal(ui, rpath, wd=None):
     """Return (path, local ui object) for the given target path.
 
     Takes paths in [cwd]/.hg/hgrc into account."
     """
     if wd is None:
         try:
             wd = os.getcwd()
         except OSError as e:
             raise error.Abort(_("error getting current working directory: %s") %
                               e.strerror)
     path = cmdutil.findrepo(wd) or ""
     if not path:
         lui = ui
     else:
         lui = ui.copy()
         lui.readconfig(os.path.join(path, ".hg", "hgrc"), path)
 
     if rpath and rpath[-1]:
         path = lui.expandpath(rpath[-1])
         lui = ui.copy()
         lui.readconfig(os.path.join(path, ".hg", "hgrc"), path)
 
     return path, lui
 
 def _checkshellalias(lui, ui, args, precheck=True):
     """Return the function to run the shell alias, if it is required
 
     'precheck' is whether this function is invoked before adding
     aliases or not.
     """
     options = {}
 
     try:
         args = fancyopts.fancyopts(args, commands.globalopts, options)
     except fancyopts.getopt.GetoptError:
         return
 
     if not args:
         return
 
     if precheck:
         strict = True
         cmdtable = commands.table.copy()
         addaliases(lui, cmdtable)
     else:
         strict = False
         cmdtable = commands.table
 
     cmd = args[0]
     try:
         aliases, entry = cmdutil.findcmd(cmd, cmdtable, strict)
     except (error.AmbiguousCommand, error.UnknownCommand):
         return
 
     cmd = aliases[0]
     fn = entry[0]
 
     if cmd and util.safehasattr(fn, 'shell'):
         d = lambda: fn(ui, *args[1:])
         return lambda: runcommand(lui, None, cmd, args[:1], ui, options, d,
                                   [], {})
 
 def _cmdattr(ui, cmd, func, attr):
     try:
         return getattr(func, attr)
     except AttributeError:
         ui.deprecwarn("missing attribute '%s', use @command decorator "
                       "to register '%s'" % (attr, cmd), '3.8')
         return False
 
 _loaded = set()
 
 # list of (objname, loadermod, loadername) tuple:
 # - objname is the name of an object in extension module, from which
 #   extra information is loaded
 # - loadermod is the module where loader is placed
 # - loadername is the name of the function, which takes (ui, extensionname,
 #   extraobj) arguments
 extraloaders = [
     ('cmdtable', commands, 'loadcmdtable'),
     ('filesetpredicate', fileset, 'loadpredicate'),
     ('revsetpredicate', revset, 'loadpredicate'),
     ('templatefilter', templatefilters, 'loadfilter'),
     ('templatefunc', templater, 'loadfunction'),
     ('templatekeyword', templatekw, 'loadkeyword'),
 ]
 
 def _dispatch(req):
     args = req.args
     ui = req.ui
 
     # check for cwd
     cwd = _earlygetopt(['--cwd'], args)
     if cwd:
         os.chdir(cwd[-1])
 
     rpath = _earlygetopt(["-R", "--repository", "--repo"], args)
     path, lui = _getlocal(ui, rpath)
 
     # Now that we're operating in the right directory/repository with
     # the right config settings, check for shell aliases
     shellaliasfn = _checkshellalias(lui, ui, args)
     if shellaliasfn:
         return shellaliasfn()
 
     # Configure extensions in phases: uisetup, extsetup, cmdtable, and
     # reposetup. Programs like TortoiseHg will call _dispatch several
     # times so we keep track of configured extensions in _loaded.
     extensions.loadall(lui)
     exts = [ext for ext in extensions.extensions() if ext[0] not in _loaded]
     # Propagate any changes to lui.__class__ by extensions
     ui.__class__ = lui.__class__
 
     # (uisetup and extsetup are handled in extensions.loadall)
 
     for name, module in exts:
         for objname, loadermod, loadername in extraloaders:
             extraobj = getattr(module, objname, None)
             if extraobj is not None:
                 getattr(loadermod, loadername)(ui, name, extraobj)
         _loaded.add(name)
 
     # (reposetup is handled in hg.repository)
 
     addaliases(lui, commands.table)
 
     if not lui.configbool("ui", "strict"):
         # All aliases and commands are completely defined, now.
         # Check abbreviation/ambiguity of shell alias again, because shell
         # alias may cause failure of "_parse" (see issue4355)
         shellaliasfn = _checkshellalias(lui, ui, args, precheck=False)
         if shellaliasfn:
             return shellaliasfn()
 
     # check for fallback encoding
     fallback = lui.config('ui', 'fallbackencoding')
     if fallback:
         encoding.fallbackencoding = fallback
 
     fullargs = args
     cmd, func, args, options, cmdoptions = _parse(lui, args)
 
     if options["config"]:
         raise error.Abort(_("option --config may not be abbreviated!"))
     if options["cwd"]:
         raise error.Abort(_("option --cwd may not be abbreviated!"))
     if options["repository"]:
         raise error.Abort(_(
             "option -R has to be separated from other options (e.g. not -qR) "
             "and --repository may only be abbreviated as --repo!"))
 
     if options["encoding"]:
         encoding.encoding = options["encoding"]
     if options["encodingmode"]:
         encoding.encodingmode = options["encodingmode"]
     if options["time"]:
         def get_times():
             t = os.times()
             if t[4] == 0.0: # Windows leaves this as zero, so use time.clock()
                 t = (t[0], t[1], t[2], t[3], time.clock())
             return t
         s = get_times()
         def print_time():
             t = get_times()
             ui.warn(_("time: real %.3f secs (user %.3f+%.3f sys %.3f+%.3f)\n") %
                 (t[4]-s[4], t[0]-s[0], t[2]-s[2], t[1]-s[1], t[3]-s[3]))
         atexit.register(print_time)
 
     uis = set([ui, lui])
 
     if req.repo:
         uis.add(req.repo.ui)
 
     if options['verbose'] or options['debug'] or options['quiet']:
         for opt in ('verbose', 'debug', 'quiet'):
             val = str(bool(options[opt]))
             for ui_ in uis:
                 ui_.setconfig('ui', opt, val, '--' + opt)
 
     if options['traceback']:
         for ui_ in uis:
             ui_.setconfig('ui', 'traceback', 'on', '--traceback')
 
     if options['noninteractive']:
         for ui_ in uis:
             ui_.setconfig('ui', 'interactive', 'off', '-y')
 
     if cmdoptions.get('insecure', False):
         for ui_ in uis:
             ui_.setconfig('web', 'cacerts', '!', '--insecure')
 
     if options['version']:
         return commands.version_(ui)
     if options['help']:
         return commands.help_(ui, cmd, command=cmd is not None)
     elif not cmd:
         return commands.help_(ui, 'shortlist')
 
     repo = None
     cmdpats = args[:]
     if not _cmdattr(ui, cmd, func, 'norepo'):
         # use the repo from the request only if we don't have -R
         if not rpath and not cwd:
             repo = req.repo
 
         if repo:
             # set the descriptors of the repo ui to those of ui
             repo.ui.fin = ui.fin
             repo.ui.fout = ui.fout
             repo.ui.ferr = ui.ferr
         else:
             try:
                 repo = hg.repository(ui, path=path)
                 if not repo.local():
                     raise error.Abort(_("repository '%s' is not local") % path)
                 repo.ui.setconfig("bundle", "mainreporoot", repo.root, 'repo')
             except error.RequirementError:
                 raise
             except error.RepoError:
                 if rpath and rpath[-1]: # invalid -R path
                     raise
                 if not _cmdattr(ui, cmd, func, 'optionalrepo'):
                     if (_cmdattr(ui, cmd, func, 'inferrepo') and
                         args and not path):
                         # try to infer -R from command args
                         repos = map(cmdutil.findrepo, args)
                         guess = repos[0]
                         if guess and repos.count(guess) == len(repos):
                             req.args = ['--repository', guess] + fullargs
                             return _dispatch(req)
                     if not path:
                         raise error.RepoError(_("no repository found in '%s'"
                                                 " (.hg not found)")
                                               % os.getcwd())
                     raise
         if repo:
             ui = repo.ui
             if options['hidden']:
                 repo = repo.unfiltered()
         args.insert(0, repo)
     elif rpath:
         ui.warn(_("warning: --repository ignored\n"))
 
     msg = ' '.join(' ' in a and repr(a) or a for a in fullargs)
     ui.log("command", '%s\n', msg)
     d = lambda: util.checksignature(func)(ui, *args, **cmdoptions)
     try:
         return runcommand(lui, repo, cmd, fullargs, ui, options, d,
                           cmdpats, cmdoptions)
     finally:
         if repo and repo != req.repo:
             repo.close()
 
 def lsprofile(ui, func, fp):
     format = ui.config('profiling', 'format', default='text')
     field = ui.config('profiling', 'sort', default='inlinetime')
     limit = ui.configint('profiling', 'limit', default=30)
     climit = ui.configint('profiling', 'nested', default=0)
 
     if format not in ['text', 'kcachegrind']:
         ui.warn(_("unrecognized profiling format '%s'"
                     " - Ignored\n") % format)
         format = 'text'
 
     try:
         from . import lsprof
     except ImportError:
         raise error.Abort(_(
             'lsprof not available - install from '
             'http://codespeak.net/svn/user/arigo/hack/misc/lsprof/'))
     p = lsprof.Profiler()
     p.enable(subcalls=True)
     try:
         return func()
     finally:
         p.disable()
 
         if format == 'kcachegrind':
             from . import lsprofcalltree
             calltree = lsprofcalltree.KCacheGrind(p)
             calltree.output(fp)
         else:
             # format == 'text'
             stats = lsprof.Stats(p.getstats())
             stats.sort(field)
             stats.pprint(limit=limit, file=fp, climit=climit)
 
 def flameprofile(ui, func, fp):
     try:
         from flamegraph import flamegraph
     except ImportError:
         raise error.Abort(_(
             'flamegraph not available - install from '
             'https://github.com/evanhempel/python-flamegraph'))
     # developer config: profiling.freq
     freq = ui.configint('profiling', 'freq', default=1000)
     filter_ = None
     collapse_recursion = True
     thread = flamegraph.ProfileThread(fp, 1.0 / freq,
                                       filter_, collapse_recursion)
     start_time = time.clock()
     try:
         thread.start()
         func()
     finally:
         thread.stop()
         thread.join()
         print('Collected %d stack frames (%d unique) in %2.2f seconds.' % (
             time.clock() - start_time, thread.num_frames(),
             thread.num_frames(unique=True)))
 
 
 def statprofile(ui, func, fp):
     try:
         import statprof
     except ImportError:
         raise error.Abort(_(
             'statprof not available - install using "easy_install statprof"'))
 
     freq = ui.configint('profiling', 'freq', default=1000)
     if freq > 0:
         statprof.reset(freq)
     else:
         ui.warn(_("invalid sampling frequency '%s' - ignoring\n") % freq)
 
     statprof.start()
     try:
         return func()
     finally:
         statprof.stop()
         statprof.display(fp)
 
 def _runcommand(ui, options, cmd, cmdfunc):
     """Enables the profiler if applicable.
 
     ``profiling.enabled`` - boolean config that enables or disables profiling
     """
     def checkargs():
         try:
             return cmdfunc()
         except error.SignatureError:
             raise error.CommandError(cmd, _("invalid arguments"))
 
     if options['profile'] or ui.configbool('profiling', 'enabled'):
         profiler = os.getenv('HGPROF')
         if profiler is None:
             profiler = ui.config('profiling', 'type', default='ls')
         if profiler not in ('ls', 'stat', 'flame'):
             ui.warn(_("unrecognized profiler '%s' - ignored\n") % profiler)
             profiler = 'ls'
 
         output = ui.config('profiling', 'output')
 
         if output == 'blackbox':
             fp = util.stringio()
         elif output:
             path = ui.expandpath(output)
             fp = open(path, 'wb')
         else:
             fp = sys.stderr
 
         try:
             if profiler == 'ls':
                 return lsprofile(ui, checkargs, fp)
             elif profiler == 'flame':
                 return flameprofile(ui, checkargs, fp)
             else:
                 return statprofile(ui, checkargs, fp)
         finally:
             if output:
                 if output == 'blackbox':
                     val = "Profile:\n%s" % fp.getvalue()
                     # ui.log treats the input as a format string,
                     # so we need to escape any % signs.
                     val = val.replace('%', '%%')
                     ui.log('profile', val)
                 fp.close()
     else:
         return checkargs()
 
 def _exceptionwarning(ui):
     """Produce a warning message for the current active exception"""
 
     # For compatibility checking, we discard the portion of the hg
     # version after the + on the assumption that if a "normal
     # user" is running a build with a + in it the packager
     # probably built from fairly close to a tag and anyone with a
     # 'make local' copy of hg (where the version number can be out
     # of date) will be clueful enough to notice the implausible
     # version number and try updating.
     ct = util.versiontuple(n=2)
     worst = None, ct, ''
     if ui.config('ui', 'supportcontact', None) is None:
         for name, mod in extensions.extensions():
             testedwith = getattr(mod, 'testedwith', '')
             report = getattr(mod, 'buglink', _('the extension author.'))
             if not testedwith.strip():
                 # We found an untested extension. It's likely the culprit.
                 worst = name, 'unknown', report
                 break
 
             # Never blame on extensions bundled with Mercurial.
             if testedwith == 'internal':
                 continue
 
             tested = [util.versiontuple(t, 2) for t in testedwith.split()]
             if ct in tested:
                 continue
 
             lower = [t for t in tested if t < ct]
             nearest = max(lower or tested)
             if worst[0] is None or nearest < worst[1]:
                 worst = name, nearest, report
     if worst[0] is not None:
         name, testedwith, report = worst
         if not isinstance(testedwith, str):
             testedwith = '.'.join([str(c) for c in testedwith])
         warning = (_('** Unknown exception encountered with '
                      'possibly-broken third-party extension %s\n'
                      '** which supports versions %s of Mercurial.\n'
                      '** Please disable %s and try your action again.\n'
                      '** If that fixes the bug please report it to %s\n')
                    % (name, testedwith, name, report))
     else:
         bugtracker = ui.config('ui', 'supportcontact', None)
         if bugtracker is None:
             bugtracker = _("https://mercurial-scm.org/wiki/BugTracker")
         warning = (_("** unknown exception encountered, "
                      "please report by visiting\n** ") + bugtracker + '\n')
     warning += ((_("** Python %s\n") % sys.version.replace('\n', '')) +
                 (_("** Mercurial Distributed SCM (version %s)\n") %
                  util.version()) +
                 (_("** Extensions loaded: %s\n") %
                  ", ".join([x[0] for x in extensions.extensions()])))
     return warning
 
 def handlecommandexception(ui):
     """Produce a warning message for broken commands
 
     Called when handling an exception; the exception is reraised if
     this function returns False, ignored otherwise.
     """
     warning = _exceptionwarning(ui)
     ui.log("commandexception", "%s\n%s\n", warning, traceback.format_exc())
     ui.warn(warning)
     return False  # re-raise the exception

tests/test-alias.t

@@ -1,554 +1,572 b''
   $ HGFOO=BAR; export HGFOO
   $ cat >> $HGRCPATH <<EOF
   > [alias]
   > # should clobber ci but not commit (issue2993)
   > ci = version
   > myinit = init
   > mycommit = commit
   > optionalrepo = showconfig alias.myinit
   > cleanstatus = status -c
   > unknown = bargle
   > ambiguous = s
   > recursive = recursive
   > disabled = email
   > nodefinition =
   > noclosingquotation = '
   > no--cwd = status --cwd elsewhere
   > no-R = status -R elsewhere
   > no--repo = status --repo elsewhere
   > no--repository = status --repository elsewhere
   > no--config = status --config a.config=1
   > mylog = log
   > lognull = log -r null
   > shortlog = log --template '{rev} {node|short} | {date|isodate}\n'
   > positional = log --template '{\$2} {\$1} | {date|isodate}\n'
   > dln = lognull --debug
   > nousage = rollback
   > put = export -r 0 -o "\$FOO/%R.diff"
   > blank = !printf '\n'
   > self = !printf '\$0\n'
   > echoall = !printf '\$@\n'
   > echo1 = !printf '\$1\n'
   > echo2 = !printf '\$2\n'
   > echo13 = !printf '\$1 \$3\n'
   > echotokens = !printf "%s\n" "\$@"
   > count = !hg log -r "\$@" --template=. | wc -c | sed -e 's/ //g'
   > mcount = !hg log \$@ --template=. | wc -c | sed -e 's/ //g'
   > rt = root
   > tglog = log -G --template "{rev}:{node|short}: '{desc}' {branches}\n"
   > idalias = id
   > idaliaslong = id
   > idaliasshell = !echo test
   > parentsshell1 = !echo one
   > parentsshell2 = !echo two
   > escaped1 = !printf 'test\$\$test\n'
   > escaped2 = !sh -c 'echo "HGFOO is \$\$HGFOO"'
   > escaped3 = !sh -c 'echo "\$1 is \$\$\$1"'
   > escaped4 = !printf '\$\$0 \$\$@\n'
   > exit1 = !sh -c 'exit 1'
   > 
   > [defaults]
   > mylog = -q
   > lognull = -q
   > log = -v
   > EOF
 
 
 basic
 
   $ hg myinit alias
 
 
 unknown
 
   $ hg unknown
   abort: alias 'unknown' resolves to unknown command 'bargle'
   [255]
   $ hg help unknown
   alias 'unknown' resolves to unknown command 'bargle'
 
 
 ambiguous
 
   $ hg ambiguous
   abort: alias 'ambiguous' resolves to ambiguous command 's'
   [255]
   $ hg help ambiguous
   alias 'ambiguous' resolves to ambiguous command 's'
 
 
 recursive
 
   $ hg recursive
   abort: alias 'recursive' resolves to unknown command 'recursive'
   [255]
   $ hg help recursive
   alias 'recursive' resolves to unknown command 'recursive'
 
 
 disabled
 
   $ hg disabled
   abort: alias 'disabled' resolves to unknown command 'email'
   ('email' is provided by 'patchbomb' extension)
   [255]
   $ hg help disabled
   alias 'disabled' resolves to unknown command 'email'
   
   'email' is provided by the following extension:
   
       patchbomb     command to send changesets as (a series of) patch emails
   
   (use "hg help extensions" for information on enabling extensions)
 
 
 no definition
 
   $ hg nodef
   abort: no definition for alias 'nodefinition'
   [255]
   $ hg help nodef
   no definition for alias 'nodefinition'
 
 
 no closing quotation
 
   $ hg noclosing
   abort: error in definition for alias 'noclosingquotation': No closing quotation
   [255]
   $ hg help noclosing
   error in definition for alias 'noclosingquotation': No closing quotation
 
 
 invalid options
 
   $ hg no--cwd
   abort: error in definition for alias 'no--cwd': --cwd may only be given on the command line
   [255]
   $ hg help no--cwd
   error in definition for alias 'no--cwd': --cwd may only be given on the
   command line
   $ hg no-R
   abort: error in definition for alias 'no-R': -R may only be given on the command line
   [255]
   $ hg help no-R
   error in definition for alias 'no-R': -R may only be given on the command line
   $ hg no--repo
   abort: error in definition for alias 'no--repo': --repo may only be given on the command line
   [255]
   $ hg help no--repo
   error in definition for alias 'no--repo': --repo may only be given on the
   command line
   $ hg no--repository
   abort: error in definition for alias 'no--repository': --repository may only be given on the command line
   [255]
   $ hg help no--repository
   error in definition for alias 'no--repository': --repository may only be given
   on the command line
   $ hg no--config
   abort: error in definition for alias 'no--config': --config may only be given on the command line
   [255]
 
 optional repository
 
 #if no-outer-repo
   $ hg optionalrepo
   init
 #endif
   $ cd alias
   $ cat > .hg/hgrc <<EOF
   > [alias]
   > myinit = init -q
   > EOF
   $ hg optionalrepo
   init -q
 
 no usage
 
   $ hg nousage
   no rollback information available
   [1]
 
   $ echo foo > foo
   $ hg commit -Amfoo
   adding foo
 
 infer repository
 
   $ cd ..
 
 #if no-outer-repo
   $ hg shortlog alias/foo
   0 e63c23eaa88a | 1970-01-01 00:00 +0000
 #endif
 
   $ cd alias
 
 with opts
 
   $ hg cleanst
   C foo
 
 
 with opts and whitespace
 
   $ hg shortlog
   0 e63c23eaa88a | 1970-01-01 00:00 +0000
 
 positional arguments
 
   $ hg positional
   abort: too few arguments for command alias
   [255]
   $ hg positional a
   abort: too few arguments for command alias
   [255]
   $ hg positional 'node|short' rev
   0 e63c23eaa88a | 1970-01-01 00:00 +0000
 
 interaction with defaults
 
   $ hg mylog
   0:e63c23eaa88a
   $ hg lognull
   -1:000000000000
 
 
 properly recursive
 
   $ hg dln
   changeset:   -1:0000000000000000000000000000000000000000
   phase:       public
   parent:      -1:0000000000000000000000000000000000000000
   parent:      -1:0000000000000000000000000000000000000000
   manifest:    -1:0000000000000000000000000000000000000000
   user:        
   date:        Thu Jan 01 00:00:00 1970 +0000
   extra:       branch=default
   
 
 
 path expanding
 
   $ FOO=`pwd` hg put
   $ cat 0.diff
   # HG changeset patch
   # User test
   # Date 0 0
   #      Thu Jan 01 00:00:00 1970 +0000
   # Node ID e63c23eaa88ae77967edcf4ea194d31167c478b0
   # Parent  0000000000000000000000000000000000000000
   foo
   
   diff -r 000000000000 -r e63c23eaa88a foo
   --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
   +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
   @@ -0,0 +1,1 @@
   +foo
 
 
 simple shell aliases
 
   $ hg blank
   
   $ hg blank foo
   
   $ hg self
   self
   $ hg echoall
   
   $ hg echoall foo
   foo
   $ hg echoall 'test $2' foo
   test $2 foo
   $ hg echoall 'test $@' foo '$@'
   test $@ foo $@
   $ hg echoall 'test "$@"' foo '"$@"'
   test "$@" foo "$@"
   $ hg echo1 foo bar baz
   foo
   $ hg echo2 foo bar baz
   bar
   $ hg echo13 foo bar baz test
   foo baz
   $ hg echo2 foo
   
   $ hg echotokens
   
   $ hg echotokens foo 'bar $1 baz'
   foo
   bar $1 baz
   $ hg echotokens 'test $2' foo
   test $2
   foo
   $ hg echotokens 'test $@' foo '$@'
   test $@
   foo
   $@
   $ hg echotokens 'test "$@"' foo '"$@"'
   test "$@"
   foo
   "$@"
   $ echo bar > bar
   $ hg commit -qA -m bar
   $ hg count .
   1
   $ hg count 'branch(default)'
   2
   $ hg mcount -r '"branch(default)"'
   2
 
   $ hg tglog
   @  1:042423737847: 'bar'
   |
   o  0:e63c23eaa88a: 'foo'
   
 
 
 shadowing
 
   $ hg i
   hg: command 'i' is ambiguous:
       idalias idaliaslong idaliasshell identify import incoming init
   [255]
   $ hg id
   042423737847 tip
   $ hg ida
   hg: command 'ida' is ambiguous:
       idalias idaliaslong idaliasshell
   [255]
   $ hg idalias
   042423737847 tip
   $ hg idaliasl
   042423737847 tip
   $ hg idaliass
   test
   $ hg parentsshell
   hg: command 'parentsshell' is ambiguous:
       parentsshell1 parentsshell2
   [255]
   $ hg parentsshell1
   one
   $ hg parentsshell2
   two
 
 
 shell aliases with global options
 
   $ hg init sub
   $ cd sub
   $ hg count 'branch(default)'
   abort: unknown revision 'default'!
   0
   $ hg -v count 'branch(default)'
   abort: unknown revision 'default'!
   0
   $ hg -R .. count 'branch(default)'
   abort: unknown revision 'default'!
   0
   $ hg --cwd .. count 'branch(default)'
   2
   $ hg echoall --cwd ..
   
 
 
 repo specific shell aliases
 
   $ cat >> .hg/hgrc <<EOF
   > [alias]
   > subalias = !echo sub
   > EOF
   $ cat >> ../.hg/hgrc <<EOF
   > [alias]
   > mainalias = !echo main
   > EOF
 
 
 shell alias defined in current repo
 
   $ hg subalias
   sub
   $ hg --cwd .. subalias > /dev/null
   hg: unknown command 'subalias'
   (did you mean idalias?)
   [255]
   $ hg -R .. subalias > /dev/null
   hg: unknown command 'subalias'
   (did you mean idalias?)
   [255]
 
 
 shell alias defined in other repo
 
   $ hg mainalias > /dev/null
   hg: unknown command 'mainalias'
   (did you mean idalias?)
   [255]
   $ hg -R .. mainalias
   main
   $ hg --cwd .. mainalias
   main
 
 typos get useful suggestions
   $ hg --cwd .. manalias
   hg: unknown command 'manalias'
   (did you mean one of idalias, mainalias, manifest?)
   [255]
 
 shell aliases with escaped $ chars
 
   $ hg escaped1
   test$test
   $ hg escaped2
   HGFOO is BAR
   $ hg escaped3 HGFOO
   HGFOO is BAR
   $ hg escaped4 test
   $0 $@
 
 abbreviated name, which matches against both shell alias and the
 command provided extension, should be aborted.
 
   $ cat >> .hg/hgrc <<EOF
   > [extensions]
   > hgext.rebase =
   > EOF
 #if windows
   $ cat >> .hg/hgrc <<EOF
   > [alias]
   > rebate = !echo this is %HG_ARGS%
   > EOF
 #else
   $ cat >> .hg/hgrc <<EOF
   > [alias]
   > rebate = !echo this is \$HG_ARGS
   > EOF
 #endif
   $ hg reba
   hg: command 'reba' is ambiguous:
       rebase rebate
   [255]
   $ hg rebat
   this is rebate
   $ hg rebat --foo-bar
   this is rebate --foo-bar
 
 invalid arguments
 
   $ hg rt foo
   hg rt: invalid arguments
   hg rt
   
   alias for: hg root
   
   (use "hg rt -h" to show more help)
   [255]
 
 invalid global arguments for normal commands, aliases, and shell aliases
 
   $ hg --invalid root
   hg: option --invalid not recognized
   Mercurial Distributed SCM
   
   basic commands:
   
    add           add the specified files on the next commit
    annotate      show changeset information by line for each file
    clone         make a copy of an existing repository
    commit        commit the specified files or all outstanding changes
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    forget        forget the specified files on the next commit
    init          create a new repository in the given directory
    log           show revision history of entire repository or files
    merge         merge another revision into working directory
    pull          pull changes from the specified source
    push          push changes to the specified destination
    remove        remove the specified files on the next commit
    serve         start stand-alone webserver
    status        show changed files in the working directory
    summary       summarize working directory state
    update        update working directory (or switch revisions)
   
   (use "hg help" for the full list of commands or "hg -v" for details)
   [255]
   $ hg --invalid mylog
   hg: option --invalid not recognized
   Mercurial Distributed SCM
   
   basic commands:
   
    add           add the specified files on the next commit
    annotate      show changeset information by line for each file
    clone         make a copy of an existing repository
    commit        commit the specified files or all outstanding changes
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    forget        forget the specified files on the next commit
    init          create a new repository in the given directory
    log           show revision history of entire repository or files
    merge         merge another revision into working directory
    pull          pull changes from the specified source
    push          push changes to the specified destination
    remove        remove the specified files on the next commit
    serve         start stand-alone webserver
    status        show changed files in the working directory
    summary       summarize working directory state
    update        update working directory (or switch revisions)
   
   (use "hg help" for the full list of commands or "hg -v" for details)
   [255]
   $ hg --invalid blank
   hg: option --invalid not recognized
   Mercurial Distributed SCM
   
   basic commands:
   
    add           add the specified files on the next commit
    annotate      show changeset information by line for each file
    clone         make a copy of an existing repository
    commit        commit the specified files or all outstanding changes
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    forget        forget the specified files on the next commit
    init          create a new repository in the given directory
    log           show revision history of entire repository or files
    merge         merge another revision into working directory
    pull          pull changes from the specified source
    push          push changes to the specified destination
    remove        remove the specified files on the next commit
    serve         start stand-alone webserver
    status        show changed files in the working directory
    summary       summarize working directory state
    update        update working directory (or switch revisions)
   
   (use "hg help" for the full list of commands or "hg -v" for details)
   [255]
 
+environment variable changes in alias commands
+
+  $ cat > $TESTTMP/setcount.py <<EOF
+  > import os
+  > def uisetup(ui):
+  >     os.environ['COUNT'] = '2'
+  > EOF
+
+  $ cat >> $HGRCPATH <<'EOF'
+  > [extensions]
+  > setcount = $TESTTMP/setcount.py
+  > [alias]
+  > showcount = log -T "$COUNT\n" -r .
+  > EOF
+
+  $ COUNT=1 hg showcount
+  2
+
 This should show id:
 
   $ hg --config alias.log='id' log
   000000000000 tip
 
 This shouldn't:
 
   $ hg --config alias.log='id' history
 
   $ cd ../..
 
 return code of command and shell aliases:
 
   $ hg mycommit -R alias
   nothing changed
   [1]
   $ hg exit1
   [1]
 
 #if no-outer-repo
   $ hg root
   abort: no repository found in '$TESTTMP' (.hg not found)!
   [255]
   $ hg --config alias.hgroot='!hg root' hgroot
   abort: no repository found in '$TESTTMP' (.hg not found)!
   [255]
 #endif