dispatch: don't rewrap aliases that have the same definition

Previously aliases that overrode existing commands would wrap the old alias
on every call to dispatch() (twice actually), which is an obvious re-entrancy
issue for things like the command server or TortoiseHG.

mercurial/dispatch.py

@@ -1,733 +1,742 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 i18n import _
 import os, sys, atexit, signal, pdb, socket, errno, shlex, time, traceback, re
 import util, commands, hg, fancyopts, extensions, hook, error
 import cmdutil, encoding
 import ui as uimod
 
 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:])))
 
 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')
 
         # 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 util.Abort, inst:
         ferr.write(_("abort: %s\n") % inst)
         if inst.hint:
             ferr.write(_("(%s)\n") % inst.hint)
         return -1
     except error.ParseError, inst:
         if len(inst.args) > 1:
             ferr.write(_("hg: parse error at %s: %s\n") %
                              (inst.args[1], inst.args[0]))
         else:
             ferr.write(_("hg: parse error: %s\n") % inst.args[0])
         return -1
 
     return _runcatch(req)
 
 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:
             # 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"))
                 pdb.set_trace()
             try:
                 return _dispatch(req)
             finally:
                 ui.flush()
         except:
             # enter the debugger when we hit an exception
             if '--debugger' in req.args:
                 traceback.print_exc()
                 pdb.post_mortem(sys.exc_info()[2])
             ui.traceback()
             raise
 
     # Global exception handling, alphabetically
     # Mercurial-specific first, followed by built-in and library exceptions
     except error.AmbiguousCommand, inst:
         ui.warn(_("hg: command '%s' is ambiguous:\n    %s\n") %
                 (inst.args[0], " ".join(inst.args[1])))
     except error.ParseError, inst:
         if len(inst.args) > 1:
             ui.warn(_("hg: parse error at %s: %s\n") %
                              (inst.args[1], inst.args[0]))
         else:
             ui.warn(_("hg: parse error: %s\n") % inst.args[0])
         return -1
     except error.LockHeld, 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, inst:
         ui.warn(_("abort: could not lock %s: %s\n") %
                (inst.desc or inst.filename, inst.strerror))
     except error.CommandError, 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.RepoError, inst:
         ui.warn(_("abort: %s!\n") % inst)
         if inst.hint:
             ui.warn(_("(%s)\n") % inst.hint)
     except error.ResponseError, 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.RevlogError, inst:
         ui.warn(_("abort: %s!\n") % inst)
     except error.SignalInterrupt:
         ui.warn(_("killed!\n"))
     except error.UnknownCommand, 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:
             commands.help_(ui, 'shortlist')
     except util.Abort, inst:
         ui.warn(_("abort: %s\n") % inst)
         if inst.hint:
             ui.warn(_("(%s)\n") % inst.hint)
     except ImportError, 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, inst:
         if hasattr(inst, "code"):
             ui.warn(_("abort: %s\n") % inst)
         elif hasattr(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
             ui.warn(_("abort: error: %s\n") % reason)
         elif hasattr(inst, "args") and inst.args[0] == errno.EPIPE:
             if ui.debugflag:
                 ui.warn(_("broken pipe\n"))
         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, inst:
         if getattr(inst, "filename", None):
             ui.warn(_("abort: %s: %s\n") % (inst.strerror, inst.filename))
         else:
             ui.warn(_("abort: %s\n") % inst.strerror)
     except KeyboardInterrupt:
         try:
             ui.warn(_("interrupted!\n"))
         except IOError, inst:
             if inst.errno == errno.EPIPE:
                 if ui.debugflag:
                     ui.warn(_("\nbroken pipe\n"))
             else:
                 raise
     except MemoryError:
         ui.warn(_("abort: out of memory\n"))
     except SystemExit, 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, inst:
         ui.warn(_("abort: %s\n") % inst.args[-1])
     except:
         ui.warn(_("** unknown exception encountered,"
                   " please report by visiting\n"))
         ui.warn(_("**  http://mercurial.selenic.com/wiki/BugTracker\n"))
         ui.warn(_("** Python %s\n") % sys.version.replace('\n', ''))
         ui.warn(_("** Mercurial Distributed SCM (version %s)\n")
                % util.version())
         ui.warn(_("** Extensions loaded: %s\n")
                % ", ".join([x[0] for x in extensions.extensions()]))
         raise
 
     return -1
 
 def aliasargs(fn, givenargs):
     args = getattr(fn, 'args', [])
     if args and givenargs:
         cmd = ' '.join(map(util.shellquote, args))
 
         nums = []
         def replacer(m):
             num = int(m.group(1)) - 1
             nums.append(num)
             return givenargs[num]
         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
 
 class cmdalias(object):
     def __init__(self, name, definition, cmdtable):
         self.name = self.cmd = name
         self.cmdname = ''
         self.definition = definition
         self.args = []
         self.opts = []
         self.help = ''
         self.norepo = True
         self.badalias = False
 
         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:
             def fn(ui, *args):
                 ui.warn(_("no definition for alias '%s'\n") % self.name)
                 return 1
             self.fn = fn
             self.badalias = True
 
             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:])
                 replace = dict((str(i + 1), arg) for i, arg in enumerate(args))
                 replace['0'] = self.name
                 replace['@'] = ' '.join(args)
                 cmd = util.interpolate(r'\$', replace, cmd, escape_prefix=True)
                 return util.system(cmd, environ=env, out=ui.fout)
             self.fn = fn
             return
 
         args = shlex.split(self.definition)
         self.cmdname = cmd = args.pop(0)
         args = map(util.expandpath, args)
 
         for invalidarg in ("--cwd", "-R", "--repository", "--repo"):
             if _earlygetopt([invalidarg], args):
                 def fn(ui, *args):
                     ui.warn(_("error in definition for alias '%s': %s may only "
                               "be given on the command line\n")
                             % (self.name, invalidarg))
                     return 1
 
                 self.fn = fn
                 self.badalias = True
                 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 cmd not in commands.norepo.split(' '):
                 self.norepo = False
             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:
             def fn(ui, *args):
                 ui.warn(_("alias '%s' resolves to unknown command '%s'\n") \
                             % (self.name, cmd))
                 try:
                     # check if the command is in a disabled extension
                     commands.help_(ui, cmd, unknowncmd=True)
                 except error.UnknownCommand:
                     pass
                 return 1
             self.fn = fn
             self.badalias = True
         except error.AmbiguousCommand:
             def fn(ui, *args):
                 ui.warn(_("alias '%s' resolves to ambiguous command '%s'\n") \
                             % (self.name, cmd))
                 return 1
             self.fn = fn
             self.badalias = True
 
     def __call__(self, ui, *args, **opts):
         if self.shadows:
             ui.debug("alias '%s' shadows command '%s'\n" %
                      (self.name, self.cmdname))
 
         if hasattr(self, 'shell'):
             return self.fn(ui, *args, **opts)
         else:
             try:
                 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'):
         aliasdef = cmdalias(alias, definition, cmdtable)
+
+        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.cmd] = (aliasdef, aliasdef.opts, aliasdef.help)
         if aliasdef.norepo:
             commands.norepo += ' %s' % alias
 
 def _parse(ui, args):
     options = {}
     cmdoptions = {}
 
     try:
         args = fancyopts.fancyopts(args, commands.globalopts, options)
     except fancyopts.getopt.GetoptError, inst:
         raise error.CommandError(None, inst)
 
     if args:
         cmd, args = args[0], args[1:]
         aliases, entry = cmdutil.findcmd(cmd, commands.table,
                                      ui.config("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, 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 = cfg.split('=', 1)
             section, name = name.split('.', 1)
             if not section or not name:
                 raise IndexError
             ui.setconfig(section, name, value)
             configs.append((section, name, value))
         except (IndexError, ValueError):
             raise util.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.
     """
     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:
         if args[pos] in aliases:
             if pos + 1 >= argcount:
                 # ignore and let getopt report an error if there is no value
                 break
             del args[pos]
             values.append(args.pop(pos))
             argcount -= 2
         elif args[pos][: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
     ret = hook.hook(lui, repo, "pre-%s" % cmd, False, args=" ".join(fullargs),
                     pats=cmdpats, opts=cmdoptions)
     if ret:
         return ret
     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):
     """Return (path, local ui object) for the given target path.
 
     Takes paths in [cwd]/.hg/hgrc into account."
     """
     try:
         wd = os.getcwd()
     except OSError, e:
         raise util.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:
         path = lui.expandpath(rpath[-1])
         lui = ui.copy()
         lui.readconfig(os.path.join(path, ".hg", "hgrc"), path)
 
     return path, lui
 
 def _checkshellalias(ui, args):
     cwd = os.getcwd()
     norepo = commands.norepo
     options = {}
 
     try:
         args = fancyopts.fancyopts(args, commands.globalopts, options)
     except fancyopts.getopt.GetoptError:
         return
 
     if not args:
         return
 
     _parseconfig(ui, options['config'])
     if options['cwd']:
         os.chdir(options['cwd'])
 
     path, lui = _getlocal(ui, [options['repository']])
 
     cmdtable = commands.table.copy()
     addaliases(lui, cmdtable)
 
     cmd = args[0]
     try:
         aliases, entry = cmdutil.findcmd(cmd, cmdtable, lui.config("ui", "strict"))
     except (error.AmbiguousCommand, error.UnknownCommand):
         commands.norepo = norepo
         os.chdir(cwd)
         return
 
     cmd = aliases[0]
     fn = entry[0]
 
     if cmd and hasattr(fn, 'shell'):
         d = lambda: fn(ui, *args[1:])
         return lambda: runcommand(lui, None, cmd, args[:1], ui, options, d, [], {})
 
     commands.norepo = norepo
     os.chdir(cwd)
 
 _loaded = set()
 def _dispatch(req):
     args = req.args
     ui = req.ui
 
     shellaliasfn = _checkshellalias(ui, args)
     if shellaliasfn:
         return shellaliasfn()
 
     # read --config before doing anything else
     # (e.g. to change trust settings for reading .hg/hgrc)
     cfgs = _parseconfig(ui, _earlygetopt(['--config'], args))
 
     # check for cwd
     cwd = _earlygetopt(['--cwd'], args)
     if cwd:
         os.chdir(cwd[-1])
 
     rpath = _earlygetopt(["-R", "--repository", "--repo"], args)
     path, lui = _getlocal(ui, rpath)
 
     # 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:
         cmdtable = getattr(module, 'cmdtable', {})
         overrides = [cmd for cmd in cmdtable if cmd in commands.table]
         if overrides:
             ui.warn(_("extension '%s' overrides commands: %s\n")
                     % (name, " ".join(overrides)))
         commands.table.update(cmdtable)
         _loaded.add(name)
 
     # (reposetup is handled in hg.repository)
 
     addaliases(lui, commands.table)
 
     # 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 util.Abort(_("option --config may not be abbreviated!"))
     if options["cwd"]:
         raise util.Abort(_("option --cwd may not be abbreviated!"))
     if options["repository"]:
         raise util.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)
 
         # copy configs that were passed on the cmdline (--config) to the repo ui
         for cfg in cfgs:
             req.repo.ui.setconfig(*cfg)
 
     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)
 
     if options['traceback']:
         for ui_ in uis:
             ui_.setconfig('ui', 'traceback', 'on')
 
     if options['noninteractive']:
         for ui_ in uis:
             ui_.setconfig('ui', 'interactive', 'off')
 
     if cmdoptions.get('insecure', False):
         for ui_ in uis:
             ui_.setconfig('web', 'cacerts', '')
 
     if options['help']:
         return commands.help_(ui, cmd, options['version'])
     elif options['version']:
         return commands.version_(ui)
     elif not cmd:
         return commands.help_(ui, 'shortlist')
 
     repo = None
     cmdpats = args[:]
     if cmd not in commands.norepo.split():
         # 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 util.Abort(_("repository '%s' is not local") % path)
                 repo.ui.setconfig("bundle", "mainreporoot", repo.root)
             except error.RequirementError:
                 raise
             except error.RepoError:
                 if cmd not in commands.optionalrepo.split():
                     if 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
         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", msg + "\n")
     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 _runcommand(ui, options, cmd, cmdfunc):
     def checkargs():
         try:
             return cmdfunc()
         except error.SignatureError:
             raise error.CommandError(cmd, _("invalid arguments"))
 
     if options['profile']:
         format = ui.config('profiling', 'format', default='text')
 
         if not format in ['text', 'kcachegrind']:
             ui.warn(_("unrecognized profiling format '%s'"
                         " - Ignored\n") % format)
             format = 'text'
 
         output = ui.config('profiling', 'output')
 
         if output:
             path = ui.expandpath(output)
             ostream = open(path, 'wb')
         else:
             ostream = sys.stderr
 
         try:
             from mercurial import lsprof
         except ImportError:
             raise util.Abort(_(
                 'lsprof not available - install from '
                 'http://codespeak.net/svn/user/arigo/hack/misc/lsprof/'))
         p = lsprof.Profiler()
         p.enable(subcalls=True)
         try:
             return checkargs()
         finally:
             p.disable()
 
             if format == 'kcachegrind':
                 import lsprofcalltree
                 calltree = lsprofcalltree.KCacheGrind(p)
                 calltree.output(ostream)
             else:
                 # format == 'text'
                 stats = lsprof.Stats(p.getstats())
                 stats.sort()
                 stats.pprint(top=10, file=ostream, climit=5)
 
             if output:
                 ostream.close()
     else:
         return checkargs()