serve: add and use portable spawnvp replacement

There is no standard python command to really detach a process under Windows.
Instead we use the low level API wrapped by subprocess module with all
necessary options to avoid any kind of context inheritance. Unfortunately, this
version still opens a new window for the child process.

The following have been tried:
- os.spawnv(os.P_NOWAIT): works but the child process is killed when parent
  console terminates.
- os.spawnv(os.P_DETACH): works on python25, hang on python26 when writing to
  the hgweb output socket.
- subprocess.CreateProcess() hack without shell mode: similar to
  os.spawnv(os.P_DETACH).

Fix 1/3 for issue421

mercurial/cmdutil.py

@@ -1,1166 +1,1165 b''
 # cmdutil.py - help for command processing in 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, incorporated herein by reference.
 
 from node import hex, nullid, nullrev, short
 from i18n import _
 import os, sys, errno, re, glob
 import mdiff, bdiff, util, templater, patch, error, encoding, templatekw
 import match as _match
 
 revrangesep = ':'
 
 def findpossible(cmd, table, strict=False):
     """
     Return cmd -> (aliases, command table entry)
     for each matching command.
     Return debug commands (or their aliases) only if no normal command matches.
     """
     choice = {}
     debugchoice = {}
     for e in table.keys():
         aliases = e.lstrip("^").split("|")
         found = None
         if cmd in aliases:
             found = cmd
         elif not strict:
             for a in aliases:
                 if a.startswith(cmd):
                     found = a
                     break
         if found is not None:
             if aliases[0].startswith("debug") or found.startswith("debug"):
                 debugchoice[found] = (aliases, table[e])
             else:
                 choice[found] = (aliases, table[e])
 
     if not choice and debugchoice:
         choice = debugchoice
 
     return choice
 
 def findcmd(cmd, table, strict=True):
     """Return (aliases, command table entry) for command string."""
     choice = findpossible(cmd, table, strict)
 
     if cmd in choice:
         return choice[cmd]
 
     if len(choice) > 1:
         clist = choice.keys()
         clist.sort()
         raise error.AmbiguousCommand(cmd, clist)
 
     if choice:
         return choice.values()[0]
 
     raise error.UnknownCommand(cmd)
 
 def bail_if_changed(repo):
     if repo.dirstate.parents()[1] != nullid:
         raise util.Abort(_('outstanding uncommitted merge'))
     modified, added, removed, deleted = repo.status()[:4]
     if modified or added or removed or deleted:
         raise util.Abort(_("outstanding uncommitted changes"))
 
 def logmessage(opts):
     """ get the log message according to -m and -l option """
     message = opts.get('message')
     logfile = opts.get('logfile')
 
     if message and logfile:
         raise util.Abort(_('options --message and --logfile are mutually '
                            'exclusive'))
     if not message and logfile:
         try:
             if logfile == '-':
                 message = sys.stdin.read()
             else:
                 message = open(logfile).read()
         except IOError, inst:
             raise util.Abort(_("can't read commit message '%s': %s") %
                              (logfile, inst.strerror))
     return message
 
 def loglimit(opts):
     """get the log limit according to option -l/--limit"""
     limit = opts.get('limit')
     if limit:
         try:
             limit = int(limit)
         except ValueError:
             raise util.Abort(_('limit must be a positive integer'))
         if limit <= 0: raise util.Abort(_('limit must be positive'))
     else:
         limit = None
     return limit
 
 def remoteui(src, opts):
     'build a remote ui from ui or repo and opts'
     if hasattr(src, 'baseui'): # looks like a repository
         dst = src.baseui.copy() # drop repo-specific config
         src = src.ui # copy target options from repo
     else: # assume it's a global ui object
         dst = src.copy() # keep all global options
 
     # copy ssh-specific options
     for o in 'ssh', 'remotecmd':
         v = opts.get(o) or src.config('ui', o)
         if v:
             dst.setconfig("ui", o, v)
 
     # copy bundle-specific options
     r = src.config('bundle', 'mainreporoot')
     if r:
         dst.setconfig('bundle', 'mainreporoot', r)
 
     # copy auth section settings
     for key, val in src.configitems('auth'):
         dst.setconfig('auth', key, val)
 
     return dst
 
 def revpair(repo, revs):
     '''return pair of nodes, given list of revisions. second item can
     be None, meaning use working dir.'''
 
     def revfix(repo, val, defval):
         if not val and val != 0 and defval is not None:
             val = defval
         return repo.lookup(val)
 
     if not revs:
         return repo.dirstate.parents()[0], None
     end = None
     if len(revs) == 1:
         if revrangesep in revs[0]:
             start, end = revs[0].split(revrangesep, 1)
             start = revfix(repo, start, 0)
             end = revfix(repo, end, len(repo) - 1)
         else:
             start = revfix(repo, revs[0], None)
     elif len(revs) == 2:
         if revrangesep in revs[0] or revrangesep in revs[1]:
             raise util.Abort(_('too many revisions specified'))
         start = revfix(repo, revs[0], None)
         end = revfix(repo, revs[1], None)
     else:
         raise util.Abort(_('too many revisions specified'))
     return start, end
 
 def revrange(repo, revs):
     """Yield revision as strings from a list of revision specifications."""
 
     def revfix(repo, val, defval):
         if not val and val != 0 and defval is not None:
             return defval
         return repo.changelog.rev(repo.lookup(val))
 
     seen, l = set(), []
     for spec in revs:
         if revrangesep in spec:
             start, end = spec.split(revrangesep, 1)
             start = revfix(repo, start, 0)
             end = revfix(repo, end, len(repo) - 1)
             step = start > end and -1 or 1
             for rev in xrange(start, end+step, step):
                 if rev in seen:
                     continue
                 seen.add(rev)
                 l.append(rev)
         else:
             rev = revfix(repo, spec, None)
             if rev in seen:
                 continue
             seen.add(rev)
             l.append(rev)
 
     return l
 
 def make_filename(repo, pat, node,
                   total=None, seqno=None, revwidth=None, pathname=None):
     node_expander = {
         'H': lambda: hex(node),
         'R': lambda: str(repo.changelog.rev(node)),
         'h': lambda: short(node),
         }
     expander = {
         '%': lambda: '%',
         'b': lambda: os.path.basename(repo.root),
         }
 
     try:
         if node:
             expander.update(node_expander)
         if node:
             expander['r'] = (lambda:
                     str(repo.changelog.rev(node)).zfill(revwidth or 0))
         if total is not None:
             expander['N'] = lambda: str(total)
         if seqno is not None:
             expander['n'] = lambda: str(seqno)
         if total is not None and seqno is not None:
             expander['n'] = lambda: str(seqno).zfill(len(str(total)))
         if pathname is not None:
             expander['s'] = lambda: os.path.basename(pathname)
             expander['d'] = lambda: os.path.dirname(pathname) or '.'
             expander['p'] = lambda: pathname
 
         newname = []
         patlen = len(pat)
         i = 0
         while i < patlen:
             c = pat[i]
             if c == '%':
                 i += 1
                 c = pat[i]
                 c = expander[c]()
             newname.append(c)
             i += 1
         return ''.join(newname)
     except KeyError, inst:
         raise util.Abort(_("invalid format spec '%%%s' in output filename") %
                          inst.args[0])
 
 def make_file(repo, pat, node=None,
               total=None, seqno=None, revwidth=None, mode='wb', pathname=None):
 
     writable = 'w' in mode or 'a' in mode
 
     if not pat or pat == '-':
         return writable and sys.stdout or sys.stdin
     if hasattr(pat, 'write') and writable:
         return pat
     if hasattr(pat, 'read') and 'r' in mode:
         return pat
     return open(make_filename(repo, pat, node, total, seqno, revwidth,
                               pathname),
                 mode)
 
 def expandpats(pats):
     if not util.expandglobs:
         return list(pats)
     ret = []
     for p in pats:
         kind, name = _match._patsplit(p, None)
         if kind is None:
             try:
                 globbed = glob.glob(name)
             except re.error:
                 globbed = [name]
             if globbed:
                 ret.extend(globbed)
                 continue
         ret.append(p)
     return ret
 
 def match(repo, pats=[], opts={}, globbed=False, default='relpath'):
     if not globbed and default == 'relpath':
         pats = expandpats(pats or [])
     m = _match.match(repo.root, repo.getcwd(), pats,
                     opts.get('include'), opts.get('exclude'), default)
     def badfn(f, msg):
         repo.ui.warn("%s: %s\n" % (m.rel(f), msg))
     m.bad = badfn
     return m
 
 def matchall(repo):
     return _match.always(repo.root, repo.getcwd())
 
 def matchfiles(repo, files):
     return _match.exact(repo.root, repo.getcwd(), files)
 
 def findrenames(repo, added, removed, threshold):
     '''find renamed files -- yields (before, after, score) tuples'''
     copies = {}
     ctx = repo['.']
     for r in removed:
         if r not in ctx:
             continue
         fctx = ctx.filectx(r)
 
         def score(text):
             if not len(text):
                 return 0.0
             if not fctx.cmp(text):
                 return 1.0
             if threshold == 1.0:
                 return 0.0
             orig = fctx.data()
             # bdiff.blocks() returns blocks of matching lines
             # count the number of bytes in each
             equal = 0
             alines = mdiff.splitnewlines(text)
             matches = bdiff.blocks(text, orig)
             for x1, x2, y1, y2 in matches:
                 for line in alines[x1:x2]:
                     equal += len(line)
 
             lengths = len(text) + len(orig)
             return equal * 2.0 / lengths
 
         for a in added:
             bestscore = copies.get(a, (None, threshold))[1]
             myscore = score(repo.wread(a))
             if myscore >= bestscore:
                 copies[a] = (r, myscore)
 
     for dest, v in copies.iteritems():
         source, score = v
         yield source, dest, score
 
 def addremove(repo, pats=[], opts={}, dry_run=None, similarity=None):
     if dry_run is None:
         dry_run = opts.get('dry_run')
     if similarity is None:
         similarity = float(opts.get('similarity') or 0)
     # we'd use status here, except handling of symlinks and ignore is tricky
     added, unknown, deleted, removed = [], [], [], []
     audit_path = util.path_auditor(repo.root)
     m = match(repo, pats, opts)
     for abs in repo.walk(m):
         target = repo.wjoin(abs)
         good = True
         try:
             audit_path(abs)
         except:
             good = False
         rel = m.rel(abs)
         exact = m.exact(abs)
         if good and abs not in repo.dirstate:
             unknown.append(abs)
             if repo.ui.verbose or not exact:
                 repo.ui.status(_('adding %s\n') % ((pats and rel) or abs))
         elif repo.dirstate[abs] != 'r' and (not good or not util.lexists(target)
             or (os.path.isdir(target) and not os.path.islink(target))):
             deleted.append(abs)
             if repo.ui.verbose or not exact:
                 repo.ui.status(_('removing %s\n') % ((pats and rel) or abs))
         # for finding renames
         elif repo.dirstate[abs] == 'r':
             removed.append(abs)
         elif repo.dirstate[abs] == 'a':
             added.append(abs)
     if not dry_run:
         repo.remove(deleted)
         repo.add(unknown)
     if similarity > 0:
         for old, new, score in findrenames(repo, added + unknown,
                                            removed + deleted, similarity):
             if repo.ui.verbose or not m.exact(old) or not m.exact(new):
                 repo.ui.status(_('recording removal of %s as rename to %s '
                                  '(%d%% similar)\n') %
                                (m.rel(old), m.rel(new), score * 100))
             if not dry_run:
                 repo.copy(old, new)
 
 def copy(ui, repo, pats, opts, rename=False):
     # called with the repo lock held
     #
     # hgsep => pathname that uses "/" to separate directories
     # ossep => pathname that uses os.sep to separate directories
     cwd = repo.getcwd()
     targets = {}
     after = opts.get("after")
     dryrun = opts.get("dry_run")
 
     def walkpat(pat):
         srcs = []
         m = match(repo, [pat], opts, globbed=True)
         for abs in repo.walk(m):
             state = repo.dirstate[abs]
             rel = m.rel(abs)
             exact = m.exact(abs)
             if state in '?r':
                 if exact and state == '?':
                     ui.warn(_('%s: not copying - file is not managed\n') % rel)
                 if exact and state == 'r':
                     ui.warn(_('%s: not copying - file has been marked for'
                               ' remove\n') % rel)
                 continue
             # abs: hgsep
             # rel: ossep
             srcs.append((abs, rel, exact))
         return srcs
 
     # abssrc: hgsep
     # relsrc: ossep
     # otarget: ossep
     def copyfile(abssrc, relsrc, otarget, exact):
         abstarget = util.canonpath(repo.root, cwd, otarget)
         reltarget = repo.pathto(abstarget, cwd)
         target = repo.wjoin(abstarget)
         src = repo.wjoin(abssrc)
         state = repo.dirstate[abstarget]
 
         # check for collisions
         prevsrc = targets.get(abstarget)
         if prevsrc is not None:
             ui.warn(_('%s: not overwriting - %s collides with %s\n') %
                     (reltarget, repo.pathto(abssrc, cwd),
                      repo.pathto(prevsrc, cwd)))
             return
 
         # check for overwrites
         exists = os.path.exists(target)
         if not after and exists or after and state in 'mn':
             if not opts['force']:
                 ui.warn(_('%s: not overwriting - file exists\n') %
                         reltarget)
                 return
 
         if after:
             if not exists:
                 return
         elif not dryrun:
             try:
                 if exists:
                     os.unlink(target)
                 targetdir = os.path.dirname(target) or '.'
                 if not os.path.isdir(targetdir):
                     os.makedirs(targetdir)
                 util.copyfile(src, target)
             except IOError, inst:
                 if inst.errno == errno.ENOENT:
                     ui.warn(_('%s: deleted in working copy\n') % relsrc)
                 else:
                     ui.warn(_('%s: cannot copy - %s\n') %
                             (relsrc, inst.strerror))
                     return True # report a failure
 
         if ui.verbose or not exact:
             if rename:
                 ui.status(_('moving %s to %s\n') % (relsrc, reltarget))
             else:
                 ui.status(_('copying %s to %s\n') % (relsrc, reltarget))
 
         targets[abstarget] = abssrc
 
         # fix up dirstate
         origsrc = repo.dirstate.copied(abssrc) or abssrc
         if abstarget == origsrc: # copying back a copy?
             if state not in 'mn' and not dryrun:
                 repo.dirstate.normallookup(abstarget)
         else:
             if repo.dirstate[origsrc] == 'a' and origsrc == abssrc:
                 if not ui.quiet:
                     ui.warn(_("%s has not been committed yet, so no copy "
                               "data will be stored for %s.\n")
                             % (repo.pathto(origsrc, cwd), reltarget))
                 if repo.dirstate[abstarget] in '?r' and not dryrun:
                     repo.add([abstarget])
             elif not dryrun:
                 repo.copy(origsrc, abstarget)
 
         if rename and not dryrun:
             repo.remove([abssrc], not after)
 
     # pat: ossep
     # dest ossep
     # srcs: list of (hgsep, hgsep, ossep, bool)
     # return: function that takes hgsep and returns ossep
     def targetpathfn(pat, dest, srcs):
         if os.path.isdir(pat):
             abspfx = util.canonpath(repo.root, cwd, pat)
             abspfx = util.localpath(abspfx)
             if destdirexists:
                 striplen = len(os.path.split(abspfx)[0])
             else:
                 striplen = len(abspfx)
             if striplen:
                 striplen += len(os.sep)
             res = lambda p: os.path.join(dest, util.localpath(p)[striplen:])
         elif destdirexists:
             res = lambda p: os.path.join(dest,
                                          os.path.basename(util.localpath(p)))
         else:
             res = lambda p: dest
         return res
 
     # pat: ossep
     # dest ossep
     # srcs: list of (hgsep, hgsep, ossep, bool)
     # return: function that takes hgsep and returns ossep
     def targetpathafterfn(pat, dest, srcs):
         if _match.patkind(pat):
             # a mercurial pattern
             res = lambda p: os.path.join(dest,
                                          os.path.basename(util.localpath(p)))
         else:
             abspfx = util.canonpath(repo.root, cwd, pat)
             if len(abspfx) < len(srcs[0][0]):
                 # A directory. Either the target path contains the last
                 # component of the source path or it does not.
                 def evalpath(striplen):
                     score = 0
                     for s in srcs:
                         t = os.path.join(dest, util.localpath(s[0])[striplen:])
                         if os.path.exists(t):
                             score += 1
                     return score
 
                 abspfx = util.localpath(abspfx)
                 striplen = len(abspfx)
                 if striplen:
                     striplen += len(os.sep)
                 if os.path.isdir(os.path.join(dest, os.path.split(abspfx)[1])):
                     score = evalpath(striplen)
                     striplen1 = len(os.path.split(abspfx)[0])
                     if striplen1:
                         striplen1 += len(os.sep)
                     if evalpath(striplen1) > score:
                         striplen = striplen1
                 res = lambda p: os.path.join(dest,
                                              util.localpath(p)[striplen:])
             else:
                 # a file
                 if destdirexists:
                     res = lambda p: os.path.join(dest,
                                         os.path.basename(util.localpath(p)))
                 else:
                     res = lambda p: dest
         return res
 
 
     pats = expandpats(pats)
     if not pats:
         raise util.Abort(_('no source or destination specified'))
     if len(pats) == 1:
         raise util.Abort(_('no destination specified'))
     dest = pats.pop()
     destdirexists = os.path.isdir(dest) and not os.path.islink(dest)
     if not destdirexists:
         if len(pats) > 1 or _match.patkind(pats[0]):
             raise util.Abort(_('with multiple sources, destination must be an '
                                'existing directory'))
         if util.endswithsep(dest):
             raise util.Abort(_('destination %s is not a directory') % dest)
 
     tfn = targetpathfn
     if after:
         tfn = targetpathafterfn
     copylist = []
     for pat in pats:
         srcs = walkpat(pat)
         if not srcs:
             continue
         copylist.append((tfn(pat, dest, srcs), srcs))
     if not copylist:
         raise util.Abort(_('no files to copy'))
 
     errors = 0
     for targetpath, srcs in copylist:
         for abssrc, relsrc, exact in srcs:
             if copyfile(abssrc, relsrc, targetpath(abssrc), exact):
                 errors += 1
 
     if errors:
         ui.warn(_('(consider using --after)\n'))
 
     return errors
 
 def service(opts, parentfn=None, initfn=None, runfn=None, logfile=None,
     runargs=None, appendpid=False):
     '''Run a command as a service.'''
 
     if opts['daemon'] and not opts['daemon_pipefds']:
         rfd, wfd = os.pipe()
         if not runargs:
             runargs = sys.argv[:]
         runargs.append('--daemon-pipefds=%d,%d' % (rfd, wfd))
         # Don't pass --cwd to the child process, because we've already
         # changed directory.
         for i in xrange(1,len(runargs)):
             if runargs[i].startswith('--cwd='):
                 del runargs[i]
                 break
             elif runargs[i].startswith('--cwd'):
                 del runargs[i:i+2]
                 break
-        pid = os.spawnvp(os.P_NOWAIT | getattr(os, 'P_DETACH', 0),
-                         runargs[0], runargs)
+        pid = util.spawndetached(runargs)
         os.close(wfd)
         os.read(rfd, 1)
         if parentfn:
             return parentfn(pid)
         else:
             return
 
     if initfn:
         initfn()
 
     if opts['pid_file']:
         mode = appendpid and 'a' or 'w'
         fp = open(opts['pid_file'], mode)
         fp.write(str(os.getpid()) + '\n')
         fp.close()
 
     if opts['daemon_pipefds']:
         rfd, wfd = [int(x) for x in opts['daemon_pipefds'].split(',')]
         os.close(rfd)
         try:
             os.setsid()
         except AttributeError:
             pass
         os.write(wfd, 'y')
         os.close(wfd)
         sys.stdout.flush()
         sys.stderr.flush()
 
         nullfd = os.open(util.nulldev, os.O_RDWR)
         logfilefd = nullfd
         if logfile:
             logfilefd = os.open(logfile, os.O_RDWR | os.O_CREAT | os.O_APPEND)
         os.dup2(nullfd, 0)
         os.dup2(logfilefd, 1)
         os.dup2(logfilefd, 2)
         if nullfd not in (0, 1, 2):
             os.close(nullfd)
         if logfile and logfilefd not in (0, 1, 2):
             os.close(logfilefd)
 
     if runfn:
         return runfn()
 
 class changeset_printer(object):
     '''show changeset information when templating not requested.'''
 
     def __init__(self, ui, repo, patch, diffopts, buffered):
         self.ui = ui
         self.repo = repo
         self.buffered = buffered
         self.patch = patch
         self.diffopts = diffopts
         self.header = {}
         self.hunk = {}
         self.lastheader = None
         self.footer = None
 
     def flush(self, rev):
         if rev in self.header:
             h = self.header[rev]
             if h != self.lastheader:
                 self.lastheader = h
                 self.ui.write(h)
             del self.header[rev]
         if rev in self.hunk:
             self.ui.write(self.hunk[rev])
             del self.hunk[rev]
             return 1
         return 0
 
     def close(self):
         if self.footer:
             self.ui.write(self.footer)
 
     def show(self, ctx, copies=None, **props):
         if self.buffered:
             self.ui.pushbuffer()
             self._show(ctx, copies, props)
             self.hunk[ctx.rev()] = self.ui.popbuffer()
         else:
             self._show(ctx, copies, props)
 
     def _show(self, ctx, copies, props):
         '''show a single changeset or file revision'''
         changenode = ctx.node()
         rev = ctx.rev()
 
         if self.ui.quiet:
             self.ui.write("%d:%s\n" % (rev, short(changenode)))
             return
 
         log = self.repo.changelog
         date = util.datestr(ctx.date())
 
         hexfunc = self.ui.debugflag and hex or short
 
         parents = [(p, hexfunc(log.node(p)))
                    for p in self._meaningful_parentrevs(log, rev)]
 
         self.ui.write(_("changeset:   %d:%s\n") % (rev, hexfunc(changenode)))
 
         branch = ctx.branch()
         # don't show the default branch name
         if branch != 'default':
             branch = encoding.tolocal(branch)
             self.ui.write(_("branch:      %s\n") % branch)
         for tag in self.repo.nodetags(changenode):
             self.ui.write(_("tag:         %s\n") % tag)
         for parent in parents:
             self.ui.write(_("parent:      %d:%s\n") % parent)
 
         if self.ui.debugflag:
             mnode = ctx.manifestnode()
             self.ui.write(_("manifest:    %d:%s\n") %
                           (self.repo.manifest.rev(mnode), hex(mnode)))
         self.ui.write(_("user:        %s\n") % ctx.user())
         self.ui.write(_("date:        %s\n") % date)
 
         if self.ui.debugflag:
             files = self.repo.status(log.parents(changenode)[0], changenode)[:3]
             for key, value in zip([_("files:"), _("files+:"), _("files-:")],
                                   files):
                 if value:
                     self.ui.write("%-12s %s\n" % (key, " ".join(value)))
         elif ctx.files() and self.ui.verbose:
             self.ui.write(_("files:       %s\n") % " ".join(ctx.files()))
         if copies and self.ui.verbose:
             copies = ['%s (%s)' % c for c in copies]
             self.ui.write(_("copies:      %s\n") % ' '.join(copies))
 
         extra = ctx.extra()
         if extra and self.ui.debugflag:
             for key, value in sorted(extra.items()):
                 self.ui.write(_("extra:       %s=%s\n")
                               % (key, value.encode('string_escape')))
 
         description = ctx.description().strip()
         if description:
             if self.ui.verbose:
                 self.ui.write(_("description:\n"))
                 self.ui.write(description)
                 self.ui.write("\n\n")
             else:
                 self.ui.write(_("summary:     %s\n") %
                               description.splitlines()[0])
         self.ui.write("\n")
 
         self.showpatch(changenode)
 
     def showpatch(self, node):
         if self.patch:
             prev = self.repo.changelog.parents(node)[0]
             chunks = patch.diff(self.repo, prev, node, match=self.patch,
                                 opts=patch.diffopts(self.ui, self.diffopts))
             for chunk in chunks:
                 self.ui.write(chunk)
             self.ui.write("\n")
 
     def _meaningful_parentrevs(self, log, rev):
         """Return list of meaningful (or all if debug) parentrevs for rev.
 
         For merges (two non-nullrev revisions) both parents are meaningful.
         Otherwise the first parent revision is considered meaningful if it
         is not the preceding revision.
         """
         parents = log.parentrevs(rev)
         if not self.ui.debugflag and parents[1] == nullrev:
             if parents[0] >= rev - 1:
                 parents = []
             else:
                 parents = [parents[0]]
         return parents
 
 
 class changeset_templater(changeset_printer):
     '''format changeset information.'''
 
     def __init__(self, ui, repo, patch, diffopts, mapfile, buffered):
         changeset_printer.__init__(self, ui, repo, patch, diffopts, buffered)
         formatnode = ui.debugflag and (lambda x: x) or (lambda x: x[:12])
         defaulttempl = {
             'parent': '{rev}:{node|formatnode} ',
             'manifest': '{rev}:{node|formatnode}',
             'file_copy': '{name} ({source})',
             'extra': '{key}={value|stringescape}'
             }
         # filecopy is preserved for compatibility reasons
         defaulttempl['filecopy'] = defaulttempl['file_copy']
         self.t = templater.templater(mapfile, {'formatnode': formatnode},
                                      cache=defaulttempl)
         self.cache = {}
 
     def use_template(self, t):
         '''set template string to use'''
         self.t.cache['changeset'] = t
 
     def _meaningful_parentrevs(self, ctx):
         """Return list of meaningful (or all if debug) parentrevs for rev.
         """
         parents = ctx.parents()
         if len(parents) > 1:
             return parents
         if self.ui.debugflag:
             return [parents[0], self.repo['null']]
         if parents[0].rev() >= ctx.rev() - 1:
             return []
         return parents
 
     def _show(self, ctx, copies, props):
         '''show a single changeset or file revision'''
 
         showlist = templatekw.showlist
 
         # showparents() behaviour depends on ui trace level which
         # causes unexpected behaviours at templating level and makes
         # it harder to extract it in a standalone function. Its
         # behaviour cannot be changed so leave it here for now.
         def showparents(repo, ctx, templ, **args):
             parents = [[('rev', p.rev()), ('node', p.hex())]
                        for p in self._meaningful_parentrevs(ctx)]
             return showlist(templ, 'parent', parents, **args)
 
         props = props.copy()
         props.update(templatekw.keywords)
         props['parents'] = showparents
         props['templ'] = self.t
         props['ctx'] = ctx
         props['repo'] = self.repo
         props['revcache'] = {'copies': copies}
         props['cache'] = self.cache
 
         # find correct templates for current mode
 
         tmplmodes = [
             (True, None),
             (self.ui.verbose, 'verbose'),
             (self.ui.quiet, 'quiet'),
             (self.ui.debugflag, 'debug'),
         ]
 
         types = {'header': '', 'footer':'', 'changeset': 'changeset'}
         for mode, postfix  in tmplmodes:
             for type in types:
                 cur = postfix and ('%s_%s' % (type, postfix)) or type
                 if mode and cur in self.t:
                     types[type] = cur
 
         try:
 
             # write header
             if types['header']:
                 h = templater.stringify(self.t(types['header'], **props))
                 if self.buffered:
                     self.header[ctx.rev()] = h
                 else:
                     self.ui.write(h)
 
             # write changeset metadata, then patch if requested
             key = types['changeset']
             self.ui.write(templater.stringify(self.t(key, **props)))
             self.showpatch(ctx.node())
 
             if types['footer']:
                 if not self.footer:
                     self.footer = templater.stringify(self.t(types['footer'],
                                                       **props))
 
         except KeyError, inst:
             msg = _("%s: no key named '%s'")
             raise util.Abort(msg % (self.t.mapfile, inst.args[0]))
         except SyntaxError, inst:
             raise util.Abort(_('%s: %s') % (self.t.mapfile, inst.args[0]))
 
 def show_changeset(ui, repo, opts, buffered=False, matchfn=False):
     """show one changeset using template or regular display.
 
     Display format will be the first non-empty hit of:
     1. option 'template'
     2. option 'style'
     3. [ui] setting 'logtemplate'
     4. [ui] setting 'style'
     If all of these values are either the unset or the empty string,
     regular display via changeset_printer() is done.
     """
     # options
     patch = False
     if opts.get('patch'):
         patch = matchfn or matchall(repo)
 
     tmpl = opts.get('template')
     style = None
     if tmpl:
         tmpl = templater.parsestring(tmpl, quoted=False)
     else:
         style = opts.get('style')
 
     # ui settings
     if not (tmpl or style):
         tmpl = ui.config('ui', 'logtemplate')
         if tmpl:
             tmpl = templater.parsestring(tmpl)
         else:
             style = ui.config('ui', 'style')
 
     if not (tmpl or style):
         return changeset_printer(ui, repo, patch, opts, buffered)
 
     mapfile = None
     if style and not tmpl:
         mapfile = style
         if not os.path.split(mapfile)[0]:
             mapname = (templater.templatepath('map-cmdline.' + mapfile)
                        or templater.templatepath(mapfile))
             if mapname: mapfile = mapname
 
     try:
         t = changeset_templater(ui, repo, patch, opts, mapfile, buffered)
     except SyntaxError, inst:
         raise util.Abort(inst.args[0])
     if tmpl: t.use_template(tmpl)
     return t
 
 def finddate(ui, repo, date):
     """Find the tipmost changeset that matches the given date spec"""
 
     df = util.matchdate(date)
     m = matchall(repo)
     results = {}
 
     def prep(ctx, fns):
         d = ctx.date()
         if df(d[0]):
             results[ctx.rev()] = d
 
     for ctx in walkchangerevs(repo, m, {'rev': None}, prep):
         rev = ctx.rev()
         if rev in results:
             ui.status(_("Found revision %s from %s\n") %
                       (rev, util.datestr(results[rev])))
             return str(rev)
 
     raise util.Abort(_("revision matching date not found"))
 
 def walkchangerevs(repo, match, opts, prepare):
     '''Iterate over files and the revs in which they changed.
 
     Callers most commonly need to iterate backwards over the history
     in which they are interested. Doing so has awful (quadratic-looking)
     performance, so we use iterators in a "windowed" way.
 
     We walk a window of revisions in the desired order.  Within the
     window, we first walk forwards to gather data, then in the desired
     order (usually backwards) to display it.
 
     This function returns an iterator yielding contexts. Before
     yielding each context, the iterator will first call the prepare
     function on each context in the window in forward order.'''
 
     def increasing_windows(start, end, windowsize=8, sizelimit=512):
         if start < end:
             while start < end:
                 yield start, min(windowsize, end-start)
                 start += windowsize
                 if windowsize < sizelimit:
                     windowsize *= 2
         else:
             while start > end:
                 yield start, min(windowsize, start-end-1)
                 start -= windowsize
                 if windowsize < sizelimit:
                     windowsize *= 2
 
     follow = opts.get('follow') or opts.get('follow_first')
 
     if not len(repo):
         return []
 
     if follow:
         defrange = '%s:0' % repo['.'].rev()
     else:
         defrange = '-1:0'
     revs = revrange(repo, opts['rev'] or [defrange])
     wanted = set()
     slowpath = match.anypats() or (match.files() and opts.get('removed'))
     fncache = {}
     change = util.cachefunc(repo.changectx)
 
     if not slowpath and not match.files():
         # No files, no patterns.  Display all revs.
         wanted = set(revs)
     copies = []
 
     if not slowpath:
         # Only files, no patterns.  Check the history of each file.
         def filerevgen(filelog, node):
             cl_count = len(repo)
             if node is None:
                 last = len(filelog) - 1
             else:
                 last = filelog.rev(node)
             for i, window in increasing_windows(last, nullrev):
                 revs = []
                 for j in xrange(i - window, i + 1):
                     n = filelog.node(j)
                     revs.append((filelog.linkrev(j),
                                  follow and filelog.renamed(n)))
                 for rev in reversed(revs):
                     # only yield rev for which we have the changelog, it can
                     # happen while doing "hg log" during a pull or commit
                     if rev[0] < cl_count:
                         yield rev
         def iterfiles():
             for filename in match.files():
                 yield filename, None
             for filename_node in copies:
                 yield filename_node
         minrev, maxrev = min(revs), max(revs)
         for file_, node in iterfiles():
             filelog = repo.file(file_)
             if not len(filelog):
                 if node is None:
                     # A zero count may be a directory or deleted file, so
                     # try to find matching entries on the slow path.
                     if follow:
                         raise util.Abort(_('cannot follow nonexistent file: "%s"') % file_)
                     slowpath = True
                     break
                 else:
                     continue
             for rev, copied in filerevgen(filelog, node):
                 if rev <= maxrev:
                     if rev < minrev:
                         break
                     fncache.setdefault(rev, [])
                     fncache[rev].append(file_)
                     wanted.add(rev)
                     if follow and copied:
                         copies.append(copied)
     if slowpath:
         if follow:
             raise util.Abort(_('can only follow copies/renames for explicit '
                                'filenames'))
 
         # The slow path checks files modified in every changeset.
         def changerevgen():
             for i, window in increasing_windows(len(repo) - 1, nullrev):
                 for j in xrange(i - window, i + 1):
                     yield change(j)
 
         for ctx in changerevgen():
             matches = filter(match, ctx.files())
             if matches:
                 fncache[ctx.rev()] = matches
                 wanted.add(ctx.rev())
 
     class followfilter(object):
         def __init__(self, onlyfirst=False):
             self.startrev = nullrev
             self.roots = set()
             self.onlyfirst = onlyfirst
 
         def match(self, rev):
             def realparents(rev):
                 if self.onlyfirst:
                     return repo.changelog.parentrevs(rev)[0:1]
                 else:
                     return filter(lambda x: x != nullrev,
                                   repo.changelog.parentrevs(rev))
 
             if self.startrev == nullrev:
                 self.startrev = rev
                 return True
 
             if rev > self.startrev:
                 # forward: all descendants
                 if not self.roots:
                     self.roots.add(self.startrev)
                 for parent in realparents(rev):
                     if parent in self.roots:
                         self.roots.add(rev)
                         return True
             else:
                 # backwards: all parents
                 if not self.roots:
                     self.roots.update(realparents(self.startrev))
                 if rev in self.roots:
                     self.roots.remove(rev)
                     self.roots.update(realparents(rev))
                     return True
 
             return False
 
     # it might be worthwhile to do this in the iterator if the rev range
     # is descending and the prune args are all within that range
     for rev in opts.get('prune', ()):
         rev = repo.changelog.rev(repo.lookup(rev))
         ff = followfilter()
         stop = min(revs[0], revs[-1])
         for x in xrange(rev, stop-1, -1):
             if ff.match(x):
                 wanted.discard(x)
 
     def iterate():
         if follow and not match.files():
             ff = followfilter(onlyfirst=opts.get('follow_first'))
             def want(rev):
                 return ff.match(rev) and rev in wanted
         else:
             def want(rev):
                 return rev in wanted
 
         for i, window in increasing_windows(0, len(revs)):
             change = util.cachefunc(repo.changectx)
             nrevs = [rev for rev in revs[i:i+window] if want(rev)]
             for rev in sorted(nrevs):
                 fns = fncache.get(rev)
                 ctx = change(rev)
                 if not fns:
                     def fns_generator():
                         for f in ctx.files():
                             if match(f):
                                 yield f
                     fns = fns_generator()
                 prepare(ctx, fns)
             for rev in nrevs:
                 yield change(rev)
     return iterate()
 
 def commit(ui, repo, commitfunc, pats, opts):
     '''commit the specified files or all outstanding changes'''
     date = opts.get('date')
     if date:
         opts['date'] = util.parsedate(date)
     message = logmessage(opts)
 
     # extract addremove carefully -- this function can be called from a command
     # that doesn't support addremove
     if opts.get('addremove'):
         addremove(repo, pats, opts)
 
     return commitfunc(ui, repo, message, match(repo, pats, opts), opts)
 
 def commiteditor(repo, ctx, subs):
     if ctx.description():
         return ctx.description()
     return commitforceeditor(repo, ctx, subs)
 
 def commitforceeditor(repo, ctx, subs):
     edittext = []
     modified, added, removed = ctx.modified(), ctx.added(), ctx.removed()
     if ctx.description():
         edittext.append(ctx.description())
     edittext.append("")
     edittext.append("") # Empty line between message and comments.
     edittext.append(_("HG: Enter commit message."
                       "  Lines beginning with 'HG:' are removed."))
     edittext.append(_("HG: Leave message empty to abort commit."))
     edittext.append("HG: --")
     edittext.append(_("HG: user: %s") % ctx.user())
     if ctx.p2():
         edittext.append(_("HG: branch merge"))
     if ctx.branch():
         edittext.append(_("HG: branch '%s'")
                         % encoding.tolocal(ctx.branch()))
     edittext.extend([_("HG: subrepo %s") % s for s in subs])
     edittext.extend([_("HG: added %s") % f for f in added])
     edittext.extend([_("HG: changed %s") % f for f in modified])
     edittext.extend([_("HG: removed %s") % f for f in removed])
     if not added and not modified and not removed:
         edittext.append(_("HG: no files changed"))
     edittext.append("")
     # run editor in the repository root
     olddir = os.getcwd()
     os.chdir(repo.root)
     text = repo.ui.edit("\n".join(edittext), ctx.user())
     text = re.sub("(?m)^HG:.*\n", "", text)
     os.chdir(olddir)
 
     if not text.strip():
         raise util.Abort(_("empty commit message"))
 
     return text

mercurial/posix.py

@@ -1,259 +1,264 b''
 # posix.py - Posix utility function implementations for Mercurial
 #
 #  Copyright 2005-2009 Matt Mackall <[e-mail]> and others
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2, incorporated herein by reference.
 
 from i18n import _
 import osutil
 import os, sys, errno, stat, getpass, pwd, grp, fcntl
 
 posixfile = open
 nulldev = '/dev/null'
 normpath = os.path.normpath
 samestat = os.path.samestat
 rename = os.rename
 expandglobs = False
 
 umask = os.umask(0)
 os.umask(umask)
 
 def openhardlinks():
     '''return true if it is safe to hold open file handles to hardlinks'''
     return True
 
 def rcfiles(path):
     rcs = [os.path.join(path, 'hgrc')]
     rcdir = os.path.join(path, 'hgrc.d')
     try:
         rcs.extend([os.path.join(rcdir, f)
                     for f, kind in osutil.listdir(rcdir)
                     if f.endswith(".rc")])
     except OSError:
         pass
     return rcs
 
 def system_rcpath():
     path = []
     # old mod_python does not set sys.argv
     if len(getattr(sys, 'argv', [])) > 0:
         path.extend(rcfiles(os.path.dirname(sys.argv[0]) +
                               '/../etc/mercurial'))
     path.extend(rcfiles('/etc/mercurial'))
     return path
 
 def user_rcpath():
     return [os.path.expanduser('~/.hgrc')]
 
 def parse_patch_output(output_line):
     """parses the output produced by patch and returns the filename"""
     pf = output_line[14:]
     if os.sys.platform == 'OpenVMS':
         if pf[0] == '`':
             pf = pf[1:-1] # Remove the quotes
     else:
         if pf.startswith("'") and pf.endswith("'") and " " in pf:
             pf = pf[1:-1] # Remove the quotes
     return pf
 
 def sshargs(sshcmd, host, user, port):
     '''Build argument list for ssh'''
     args = user and ("%s@%s" % (user, host)) or host
     return port and ("%s -p %s" % (args, port)) or args
 
 def is_exec(f):
     """check whether a file is executable"""
     return (os.lstat(f).st_mode & 0100 != 0)
 
 def set_flags(f, l, x):
     s = os.lstat(f).st_mode
     if l:
         if not stat.S_ISLNK(s):
             # switch file to link
             data = open(f).read()
             os.unlink(f)
             try:
                 os.symlink(data, f)
             except:
                 # failed to make a link, rewrite file
                 open(f, "w").write(data)
         # no chmod needed at this point
         return
     if stat.S_ISLNK(s):
         # switch link to file
         data = os.readlink(f)
         os.unlink(f)
         open(f, "w").write(data)
         s = 0666 & ~umask # avoid restatting for chmod
 
     sx = s & 0100
     if x and not sx:
         # Turn on +x for every +r bit when making a file executable
         # and obey umask.
         os.chmod(f, s | (s & 0444) >> 2 & ~umask)
     elif not x and sx:
         # Turn off all +x bits
         os.chmod(f, s & 0666)
 
 def set_binary(fd):
     pass
 
 def pconvert(path):
     return path
 
 def localpath(path):
     return path
 
 def samefile(fpath1, fpath2):
     """Returns whether path1 and path2 refer to the same file. This is only
     guaranteed to work for files, not directories."""
     return os.path.samefile(fpath1, fpath2)
 
 def samedevice(fpath1, fpath2):
     """Returns whether fpath1 and fpath2 are on the same device. This is only
     guaranteed to work for files, not directories."""
     st1 = os.lstat(fpath1)
     st2 = os.lstat(fpath2)
     return st1.st_dev == st2.st_dev
 
 if sys.platform == 'darwin':
     def realpath(path):
         '''
         Returns the true, canonical file system path equivalent to the given
         path.
 
         Equivalent means, in this case, resulting in the same, unique
         file system link to the path. Every file system entry, whether a file,
         directory, hard link or symbolic link or special, will have a single
         path preferred by the system, but may allow multiple, differing path
         lookups to point to it.
 
         Most regular UNIX file systems only allow a file system entry to be
         looked up by its distinct path. Obviously, this does not apply to case
         insensitive file systems, whether case preserving or not. The most
         complex issue to deal with is file systems transparently reencoding the
         path, such as the non-standard Unicode normalisation required for HFS+
         and HFSX.
         '''
         # Constants copied from /usr/include/sys/fcntl.h
         F_GETPATH = 50
         O_SYMLINK = 0x200000
 
         try:
             fd = os.open(path, O_SYMLINK)
         except OSError, err:
             if err.errno is errno.ENOENT:
                 return path
             raise
 
         try:
             return fcntl.fcntl(fd, F_GETPATH, '\0' * 1024).rstrip('\0')
         finally:
             os.close(fd)
 else:
     # Fallback to the likely inadequate Python builtin function.
     realpath = os.path.realpath
 
 def shellquote(s):
     if os.sys.platform == 'OpenVMS':
         return '"%s"' % s
     else:
         return "'%s'" % s.replace("'", "'\\''")
 
 def quotecommand(cmd):
     return cmd
 
 def popen(command, mode='r'):
     return os.popen(command, mode)
 
 def testpid(pid):
     '''return False if pid dead, True if running or not sure'''
     if os.sys.platform == 'OpenVMS':
         return True
     try:
         os.kill(pid, 0)
         return True
     except OSError, inst:
         return inst.errno != errno.ESRCH
 
 def explain_exit(code):
     """return a 2-tuple (desc, code) describing a subprocess status
     (codes from kill are negative - not os.system/wait encoding)"""
     if code >= 0:
         return _("exited with status %d") % code, code
     return _("killed by signal %d") % -code, -code
 
 def isowner(st):
     """Return True if the stat object st is from the current user."""
     return st.st_uid == os.getuid()
 
 def find_exe(command):
     '''Find executable for command searching like which does.
     If command is a basename then PATH is searched for command.
     PATH isn't searched if command is an absolute or relative path.
     If command isn't found None is returned.'''
     if sys.platform == 'OpenVMS':
         return command
 
     def findexisting(executable):
         'Will return executable if existing file'
         if os.path.exists(executable):
             return executable
         return None
 
     if os.sep in command:
         return findexisting(command)
 
     for path in os.environ.get('PATH', '').split(os.pathsep):
         executable = findexisting(os.path.join(path, command))
         if executable is not None:
             return executable
     return None
 
 def set_signal_handler():
     pass
 
 def statfiles(files):
     'Stat each file in files and yield stat or None if file does not exist.'
     lstat = os.lstat
     for nf in files:
         try:
             st = lstat(nf)
         except OSError, err:
             if err.errno not in (errno.ENOENT, errno.ENOTDIR):
                 raise
             st = None
         yield st
 
 def getuser():
     '''return name of current user'''
     return getpass.getuser()
 
 def expand_glob(pats):
     '''On Windows, expand the implicit globs in a list of patterns'''
     return list(pats)
 
 def username(uid=None):
     """Return the name of the user with the given uid.
 
     If uid is None, return the name of the current user."""
 
     if uid is None:
         uid = os.getuid()
     try:
         return pwd.getpwuid(uid)[0]
     except KeyError:
         return str(uid)
 
 def groupname(gid=None):
     """Return the name of the group with the given gid.
 
     If gid is None, return the name of the current group."""
 
     if gid is None:
         gid = os.getgid()
     try:
         return grp.getgrgid(gid)[0]
     except KeyError:
         return str(gid)
+
+def spawndetached(args):
+    return os.spawnvp(os.P_NOWAIT | getattr(os, 'P_DETACH', 0),
+                      args[0], args)
+

mercurial/windows.py

@@ -1,330 +1,361 b''
 # windows.py - Windows utility function implementations for Mercurial
 #
 #  Copyright 2005-2009 Matt Mackall <[e-mail]> and others
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2, incorporated herein by reference.
 
 from i18n import _
 import osutil, error
-import errno, msvcrt, os, re, sys, random
+import errno, msvcrt, os, re, sys, random, subprocess
 
 nulldev = 'NUL:'
 umask = 002
 
 # wrap osutil.posixfile to provide friendlier exceptions
 def posixfile(name, mode='r', buffering=-1):
     try:
         return osutil.posixfile(name, mode, buffering)
     except WindowsError, err:
         raise IOError(err.errno, '%s: %s' % (name, err.strerror))
 posixfile.__doc__ = osutil.posixfile.__doc__
 
 class winstdout(object):
     '''stdout on windows misbehaves if sent through a pipe'''
 
     def __init__(self, fp):
         self.fp = fp
 
     def __getattr__(self, key):
         return getattr(self.fp, key)
 
     def close(self):
         try:
             self.fp.close()
         except: pass
 
     def write(self, s):
         try:
             # This is workaround for "Not enough space" error on
             # writing large size of data to console.
             limit = 16000
             l = len(s)
             start = 0
             self.softspace = 0;
             while start < l:
                 end = start + limit
                 self.fp.write(s[start:end])
                 start = end
         except IOError, inst:
             if inst.errno != 0: raise
             self.close()
             raise IOError(errno.EPIPE, 'Broken pipe')
 
     def flush(self):
         try:
             return self.fp.flush()
         except IOError, inst:
             if inst.errno != errno.EINVAL: raise
             self.close()
             raise IOError(errno.EPIPE, 'Broken pipe')
 
 sys.stdout = winstdout(sys.stdout)
 
 def _is_win_9x():
     '''return true if run on windows 95, 98 or me.'''
     try:
         return sys.getwindowsversion()[3] == 1
     except AttributeError:
         return 'command' in os.environ.get('comspec', '')
 
 def openhardlinks():
     return not _is_win_9x() and "win32api" in globals()
 
 def system_rcpath():
     try:
         return system_rcpath_win32()
     except:
         return [r'c:\mercurial\mercurial.ini']
 
 def user_rcpath():
     '''return os-specific hgrc search path to the user dir'''
     try:
         path = user_rcpath_win32()
     except:
         home = os.path.expanduser('~')
         path = [os.path.join(home, 'mercurial.ini'),
                 os.path.join(home, '.hgrc')]
     userprofile = os.environ.get('USERPROFILE')
     if userprofile:
         path.append(os.path.join(userprofile, 'mercurial.ini'))
         path.append(os.path.join(userprofile, '.hgrc'))
     return path
 
 def parse_patch_output(output_line):
     """parses the output produced by patch and returns the filename"""
     pf = output_line[14:]
     if pf[0] == '`':
         pf = pf[1:-1] # Remove the quotes
     return pf
 
 def sshargs(sshcmd, host, user, port):
     '''Build argument list for ssh or Plink'''
     pflag = 'plink' in sshcmd.lower() and '-P' or '-p'
     args = user and ("%s@%s" % (user, host)) or host
     return port and ("%s %s %s" % (args, pflag, port)) or args
 
 def testpid(pid):
     '''return False if pid dead, True if running or not known'''
     return True
 
 def set_flags(f, l, x):
     pass
 
 def set_binary(fd):
     # When run without console, pipes may expose invalid
     # fileno(), usually set to -1.
     if hasattr(fd, 'fileno') and fd.fileno() >= 0:
         msvcrt.setmode(fd.fileno(), os.O_BINARY)
 
 def pconvert(path):
     return '/'.join(path.split(os.sep))
 
 def localpath(path):
     return path.replace('/', '\\')
 
 def normpath(path):
     return pconvert(os.path.normpath(path))
 
 def realpath(path):
     '''
     Returns the true, canonical file system path equivalent to the given
     path.
     '''
     # TODO: There may be a more clever way to do this that also handles other,
     # less common file systems.
     return os.path.normpath(os.path.normcase(os.path.realpath(path)))
 
 def samestat(s1, s2):
     return False
 
 # A sequence of backslashes is special iff it precedes a double quote:
 # - if there's an even number of backslashes, the double quote is not
 #   quoted (i.e. it ends the quoted region)
 # - if there's an odd number of backslashes, the double quote is quoted
 # - in both cases, every pair of backslashes is unquoted into a single
 #   backslash
 # (See http://msdn2.microsoft.com/en-us/library/a1y7w461.aspx )
 # So, to quote a string, we must surround it in double quotes, double
 # the number of backslashes that preceed double quotes and add another
 # backslash before every double quote (being careful with the double
 # quote we've appended to the end)
 _quotere = None
 def shellquote(s):
     global _quotere
     if _quotere is None:
         _quotere = re.compile(r'(\\*)("|\\$)')
     return '"%s"' % _quotere.sub(r'\1\1\\\2', s)
 
 def quotecommand(cmd):
     """Build a command string suitable for os.popen* calls."""
     # The extra quotes are needed because popen* runs the command
     # through the current COMSPEC. cmd.exe suppress enclosing quotes.
     return '"' + cmd + '"'
 
 def popen(command, mode='r'):
     # Work around "popen spawned process may not write to stdout
     # under windows"
     # http://bugs.python.org/issue1366
     command += " 2> %s" % nulldev
     return os.popen(quotecommand(command), mode)
 
 def explain_exit(code):
     return _("exited with status %d") % code, code
 
 # if you change this stub into a real check, please try to implement the
 # username and groupname functions above, too.
 def isowner(st):
     return True
 
 def find_exe(command):
     '''Find executable for command searching like cmd.exe does.
     If command is a basename then PATH is searched for command.
     PATH isn't searched if command is an absolute or relative path.
     An extension from PATHEXT is found and added if not present.
     If command isn't found None is returned.'''
     pathext = os.environ.get('PATHEXT', '.COM;.EXE;.BAT;.CMD')
     pathexts = [ext for ext in pathext.lower().split(os.pathsep)]
     if os.path.splitext(command)[1].lower() in pathexts:
         pathexts = ['']
 
     def findexisting(pathcommand):
         'Will append extension (if needed) and return existing file'
         for ext in pathexts:
             executable = pathcommand + ext
             if os.path.exists(executable):
                 return executable
         return None
 
     if os.sep in command:
         return findexisting(command)
 
     for path in os.environ.get('PATH', '').split(os.pathsep):
         executable = findexisting(os.path.join(path, command))
         if executable is not None:
             return executable
     return findexisting(os.path.expanduser(os.path.expandvars(command)))
 
 def set_signal_handler():
     try:
         set_signal_handler_win32()
     except NameError:
         pass
 
 def statfiles(files):
     '''Stat each file in files and yield stat or None if file does not exist.
     Cluster and cache stat per directory to minimize number of OS stat calls.'''
     ncase = os.path.normcase
     sep   = os.sep
     dircache = {} # dirname -> filename -> status | None if file does not exist
     for nf in files:
         nf  = ncase(nf)
         dir, base = os.path.split(nf)
         if not dir:
             dir = '.'
         cache = dircache.get(dir, None)
         if cache is None:
             try:
                 dmap = dict([(ncase(n), s)
                     for n, k, s in osutil.listdir(dir, True)])
             except OSError, err:
                 # handle directory not found in Python version prior to 2.5
                 # Python <= 2.4 returns native Windows code 3 in errno
                 # Python >= 2.5 returns ENOENT and adds winerror field
                 # EINVAL is raised if dir is not a directory.
                 if err.errno not in (3, errno.ENOENT, errno.EINVAL,
                                      errno.ENOTDIR):
                     raise
                 dmap = {}
             cache = dircache.setdefault(dir, dmap)
         yield cache.get(base, None)
 
 def getuser():
     '''return name of current user'''
     raise error.Abort(_('user name not available - set USERNAME '
                        'environment variable'))
 
 def username(uid=None):
     """Return the name of the user with the given uid.
 
     If uid is None, return the name of the current user."""
     return None
 
 def groupname(gid=None):
     """Return the name of the group with the given gid.
 
     If gid is None, return the name of the current group."""
     return None
 
 def _removedirs(name):
     """special version of os.removedirs that does not remove symlinked
     directories or junction points if they actually contain files"""
     if osutil.listdir(name):
         return
     os.rmdir(name)
     head, tail = os.path.split(name)
     if not tail:
         head, tail = os.path.split(head)
     while head and tail:
         try:
             if osutil.listdir(head):
                 return
             os.rmdir(head)
         except:
             break
         head, tail = os.path.split(head)
 
 def unlink(f):
     """unlink and remove the directory if it is empty"""
     os.unlink(f)
     # try removing directories that might now be empty
     try:
         _removedirs(os.path.dirname(f))
     except OSError:
         pass
 
 def rename(src, dst):
     '''atomically rename file src to dst, replacing dst if it exists'''
     try:
         os.rename(src, dst)
     except OSError, err: # FIXME: check err (EEXIST ?)
 
         # On windows, rename to existing file is not allowed, so we
         # must delete destination first. But if a file is open, unlink
         # schedules it for delete but does not delete it. Rename
         # happens immediately even for open files, so we rename
         # destination to a temporary name, then delete that. Then
         # rename is safe to do.
         # The temporary name is chosen at random to avoid the situation
         # where a file is left lying around from a previous aborted run.
         # The usual race condition this introduces can't be avoided as
         # we need the name to rename into, and not the file itself. Due
         # to the nature of the operation however, any races will at worst
         # lead to the rename failing and the current operation aborting.
 
         def tempname(prefix):
             for tries in xrange(10):
                 temp = '%s-%08x' % (prefix, random.randint(0, 0xffffffff))
                 if not os.path.exists(temp):
                     return temp
             raise IOError, (errno.EEXIST, "No usable temporary filename found")
 
         temp = tempname(dst)
         os.rename(dst, temp)
         try:
             os.unlink(temp)
         except:
             # Some rude AV-scanners on Windows may cause the unlink to
             # fail. Not aborting here just leaks the temp file, whereas
             # aborting at this point may leave serious inconsistencies.
             # Ideally, we would notify the user here.
             pass
         os.rename(src, dst)
 
+def spawndetached(args):
+    # No standard library function really spawns a fully detached
+    # process under win32 because they allocate pipes or other objects
+    # to handle standard streams communications. Passing these objects
+    # to the child process requires handle inheritance to be enabled
+    # which makes really detached processes impossible.
+    class STARTUPINFO:
+        dwFlags = subprocess.STARTF_USESHOWWINDOW
+        hStdInput = None
+        hStdOutput = None
+        hStdError = None
+        wShowWindow = subprocess.SW_HIDE
+        
+    args = subprocess.list2cmdline(args)
+    # Not running the command in shell mode makes python26 hang when
+    # writing to hgweb output socket.
+    comspec = os.environ.get("COMSPEC", "cmd.exe")
+    args = comspec + " /c " + args
+    hp, ht, pid, tid = subprocess.CreateProcess(
+        None, args,
+        # no special security
+        None, None,
+        # Do not inherit handles
+        0,
+        # DETACHED_PROCESS
+        0x00000008,
+        os.environ,
+        os.getcwd(),
+        STARTUPINFO())
+    return pid
+
 try:
     # override functions with win32 versions if possible
     from win32 import *
 except ImportError:
     pass
 
 expandglobs = True