mercurial/dispatch.py

rollback: avoid unsafe rollback when not at tip (issue2998)

You can get into trouble if you commit, update back to an older
changeset, and then rollback. The update removes your valuable changes
from the working dir, then rollback removes them history. Oops: you've
just irretrievably lost data running nothing but core Mercurial
commands. (More subtly: rollback from a shared clone that was already
at an older changeset -- no update required, just rollback from the
wrong directory.)

The fix assumes that only "commit" transactions have irreplaceable
data, and allows rolling back non-commit transactions as always. But
when rolling back a commit, check that the working dir is checked out
to tip, i.e. the changeset we're about to destroy. If not, abort. You
can get back the old (dangerous) behaviour with --force.

# 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.OutOfBandError, inst:
        ui.warn("abort: remote error:\n")
        ui.warn(''.join(inst.args))
    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 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
            ui.warn(_("abort: error: %s\n") % reason)
        elif util.safehasattr(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 util.safehasattr(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 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):
    norepo = commands.norepo
    options = {}

    try:
        args = fancyopts.fancyopts(args, commands.globalopts, options)
    except fancyopts.getopt.GetoptError:
        return

    if not args:
        return

    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
        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, [], {})

    commands.norepo = norepo

_loaded = set()
def _dispatch(req):
    args = req.args
    ui = req.ui

    # 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)

    # 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:
        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['version']:
        return commands.version_(ui)
    if options['help']:
        return commands.help_(ui, cmd)
    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()