cleanup: remove useless re-raises of KeyboardInterrupt

KeyboardInterrupt is no longer a subclass of Exception since Python 2.5.

https://docs.python.org/2/whatsnew/2.5.html#pep-352-exceptions-as-new-style-classes

mercurial/branchmap.py

@@ -1,521 +1,519 b''
 # branchmap.py - logic to computes, maintain and stores branchmap for local repo
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import struct
 
 from .node import (
     bin,
     hex,
     nullid,
     nullrev,
 )
 from . import (
     encoding,
     error,
     scmutil,
     util,
 )
 
 calcsize = struct.calcsize
 pack_into = struct.pack_into
 unpack_from = struct.unpack_from
 
 def _filename(repo):
     """name of a branchcache file for a given repo or repoview"""
     filename = "cache/branch2"
     if repo.filtername:
         filename = '%s-%s' % (filename, repo.filtername)
     return filename
 
 def read(repo):
     try:
         f = repo.vfs(_filename(repo))
         lines = f.read().split('\n')
         f.close()
     except (IOError, OSError):
         return None
 
     try:
         cachekey = lines.pop(0).split(" ", 2)
         last, lrev = cachekey[:2]
         last, lrev = bin(last), int(lrev)
         filteredhash = None
         if len(cachekey) > 2:
             filteredhash = bin(cachekey[2])
         partial = branchcache(tipnode=last, tiprev=lrev,
                               filteredhash=filteredhash)
         if not partial.validfor(repo):
             # invalidate the cache
             raise ValueError('tip differs')
         cl = repo.changelog
         for l in lines:
             if not l:
                 continue
             node, state, label = l.split(" ", 2)
             if state not in 'oc':
                 raise ValueError('invalid branch state')
             label = encoding.tolocal(label.strip())
             node = bin(node)
             if not cl.hasnode(node):
                 raise ValueError('node %s does not exist' % hex(node))
             partial.setdefault(label, []).append(node)
             if state == 'c':
                 partial._closednodes.add(node)
-    except KeyboardInterrupt:
-        raise
     except Exception as inst:
         if repo.ui.debugflag:
             msg = 'invalid branchheads cache'
             if repo.filtername is not None:
                 msg += ' (%s)' % repo.filtername
             msg += ': %s\n'
             repo.ui.debug(msg % inst)
         partial = None
     return partial
 
 ### Nearest subset relation
 # Nearest subset of filter X is a filter Y so that:
 # * Y is included in X,
 # * X - Y is as small as possible.
 # This create and ordering used for branchmap purpose.
 # the ordering may be partial
 subsettable = {None: 'visible',
                'visible': 'served',
                'served': 'immutable',
                'immutable': 'base'}
 
 def updatecache(repo):
     cl = repo.changelog
     filtername = repo.filtername
     partial = repo._branchcaches.get(filtername)
 
     revs = []
     if partial is None or not partial.validfor(repo):
         partial = read(repo)
         if partial is None:
             subsetname = subsettable.get(filtername)
             if subsetname is None:
                 partial = branchcache()
             else:
                 subset = repo.filtered(subsetname)
                 partial = subset.branchmap().copy()
                 extrarevs = subset.changelog.filteredrevs - cl.filteredrevs
                 revs.extend(r for  r in extrarevs if r <= partial.tiprev)
     revs.extend(cl.revs(start=partial.tiprev + 1))
     if revs:
         partial.update(repo, revs)
         partial.write(repo)
 
     assert partial.validfor(repo), filtername
     repo._branchcaches[repo.filtername] = partial
 
 def replacecache(repo, bm):
     """Replace the branchmap cache for a repo with a branch mapping.
 
     This is likely only called during clone with a branch map from a remote.
     """
     rbheads = []
     closed = []
     for bheads in bm.itervalues():
         rbheads.extend(bheads)
         for h in bheads:
             r = repo.changelog.rev(h)
             b, c = repo.changelog.branchinfo(r)
             if c:
                 closed.append(h)
 
     if rbheads:
         rtiprev = max((int(repo.changelog.rev(node))
                 for node in rbheads))
         cache = branchcache(bm,
                             repo[rtiprev].node(),
                             rtiprev,
                             closednodes=closed)
 
         # Try to stick it as low as possible
         # filter above served are unlikely to be fetch from a clone
         for candidate in ('base', 'immutable', 'served'):
             rview = repo.filtered(candidate)
             if cache.validfor(rview):
                 repo._branchcaches[candidate] = cache
                 cache.write(rview)
                 break
 
 class branchcache(dict):
     """A dict like object that hold branches heads cache.
 
     This cache is used to avoid costly computations to determine all the
     branch heads of a repo.
 
     The cache is serialized on disk in the following format:
 
     <tip hex node> <tip rev number> [optional filtered repo hex hash]
     <branch head hex node> <open/closed state> <branch name>
     <branch head hex node> <open/closed state> <branch name>
     ...
 
     The first line is used to check if the cache is still valid. If the
     branch cache is for a filtered repo view, an optional third hash is
     included that hashes the hashes of all filtered revisions.
 
     The open/closed state is represented by a single letter 'o' or 'c'.
     This field can be used to avoid changelog reads when determining if a
     branch head closes a branch or not.
     """
 
     def __init__(self, entries=(), tipnode=nullid, tiprev=nullrev,
                  filteredhash=None, closednodes=None):
         super(branchcache, self).__init__(entries)
         self.tipnode = tipnode
         self.tiprev = tiprev
         self.filteredhash = filteredhash
         # closednodes is a set of nodes that close their branch. If the branch
         # cache has been updated, it may contain nodes that are no longer
         # heads.
         if closednodes is None:
             self._closednodes = set()
         else:
             self._closednodes = closednodes
 
     def validfor(self, repo):
         """Is the cache content valid regarding a repo
 
         - False when cached tipnode is unknown or if we detect a strip.
         - True when cache is up to date or a subset of current repo."""
         try:
             return ((self.tipnode == repo.changelog.node(self.tiprev))
                     and (self.filteredhash == \
                          scmutil.filteredhash(repo, self.tiprev)))
         except IndexError:
             return False
 
     def _branchtip(self, heads):
         '''Return tuple with last open head in heads and false,
         otherwise return last closed head and true.'''
         tip = heads[-1]
         closed = True
         for h in reversed(heads):
             if h not in self._closednodes:
                 tip = h
                 closed = False
                 break
         return tip, closed
 
     def branchtip(self, branch):
         '''Return the tipmost open head on branch head, otherwise return the
         tipmost closed head on branch.
         Raise KeyError for unknown branch.'''
         return self._branchtip(self[branch])[0]
 
     def branchheads(self, branch, closed=False):
         heads = self[branch]
         if not closed:
             heads = [h for h in heads if h not in self._closednodes]
         return heads
 
     def iterbranches(self):
         for bn, heads in self.iteritems():
             yield (bn, heads) + self._branchtip(heads)
 
     def copy(self):
         """return an deep copy of the branchcache object"""
         return branchcache(self, self.tipnode, self.tiprev, self.filteredhash,
                            self._closednodes)
 
     def write(self, repo):
         try:
             f = repo.vfs(_filename(repo), "w", atomictemp=True)
             cachekey = [hex(self.tipnode), '%d' % self.tiprev]
             if self.filteredhash is not None:
                 cachekey.append(hex(self.filteredhash))
             f.write(" ".join(cachekey) + '\n')
             nodecount = 0
             for label, nodes in sorted(self.iteritems()):
                 for node in nodes:
                     nodecount += 1
                     if node in self._closednodes:
                         state = 'c'
                     else:
                         state = 'o'
                     f.write("%s %s %s\n" % (hex(node), state,
                                             encoding.fromlocal(label)))
             f.close()
             repo.ui.log('branchcache',
                         'wrote %s branch cache with %d labels and %d nodes\n',
                         repo.filtername, len(self), nodecount)
         except (IOError, OSError, error.Abort) as inst:
             repo.ui.debug("couldn't write branch cache: %s\n" % inst)
             # Abort may be raise by read only opener
             pass
 
     def update(self, repo, revgen):
         """Given a branchhead cache, self, that may have extra nodes or be
         missing heads, and a generator of nodes that are strictly a superset of
         heads missing, this function updates self to be correct.
         """
         starttime = util.timer()
         cl = repo.changelog
         # collect new branch entries
         newbranches = {}
         getbranchinfo = repo.revbranchcache().branchinfo
         for r in revgen:
             branch, closesbranch = getbranchinfo(r)
             newbranches.setdefault(branch, []).append(r)
             if closesbranch:
                 self._closednodes.add(cl.node(r))
 
         # fetch current topological heads to speed up filtering
         topoheads = set(cl.headrevs())
 
         # if older branchheads are reachable from new ones, they aren't
         # really branchheads. Note checking parents is insufficient:
         # 1 (branch a) -> 2 (branch b) -> 3 (branch a)
         for branch, newheadrevs in newbranches.iteritems():
             bheads = self.setdefault(branch, [])
             bheadset = set(cl.rev(node) for node in bheads)
 
             # This have been tested True on all internal usage of this function.
             # run it again in case of doubt
             # assert not (set(bheadrevs) & set(newheadrevs))
             newheadrevs.sort()
             bheadset.update(newheadrevs)
 
             # This prunes out two kinds of heads - heads that are superseded by
             # a head in newheadrevs, and newheadrevs that are not heads because
             # an existing head is their descendant.
             uncertain = bheadset - topoheads
             if uncertain:
                 floorrev = min(uncertain)
                 ancestors = set(cl.ancestors(newheadrevs, floorrev))
                 bheadset -= ancestors
             bheadrevs = sorted(bheadset)
             self[branch] = [cl.node(rev) for rev in bheadrevs]
             tiprev = bheadrevs[-1]
             if tiprev > self.tiprev:
                 self.tipnode = cl.node(tiprev)
                 self.tiprev = tiprev
 
         if not self.validfor(repo):
             # cache key are not valid anymore
             self.tipnode = nullid
             self.tiprev = nullrev
             for heads in self.values():
                 tiprev = max(cl.rev(node) for node in heads)
                 if tiprev > self.tiprev:
                     self.tipnode = cl.node(tiprev)
                     self.tiprev = tiprev
         self.filteredhash = scmutil.filteredhash(repo, self.tiprev)
 
         duration = util.timer() - starttime
         repo.ui.log('branchcache', 'updated %s branch cache in %.4f seconds\n',
                     repo.filtername, duration)
 
 # Revision branch info cache
 
 _rbcversion = '-v1'
 _rbcnames = 'cache/rbc-names' + _rbcversion
 _rbcrevs = 'cache/rbc-revs' + _rbcversion
 # [4 byte hash prefix][4 byte branch name number with sign bit indicating open]
 _rbcrecfmt = '>4sI'
 _rbcrecsize = calcsize(_rbcrecfmt)
 _rbcnodelen = 4
 _rbcbranchidxmask = 0x7fffffff
 _rbccloseflag = 0x80000000
 
 class revbranchcache(object):
     """Persistent cache, mapping from revision number to branch name and close.
     This is a low level cache, independent of filtering.
 
     Branch names are stored in rbc-names in internal encoding separated by 0.
     rbc-names is append-only, and each branch name is only stored once and will
     thus have a unique index.
 
     The branch info for each revision is stored in rbc-revs as constant size
     records. The whole file is read into memory, but it is only 'parsed' on
     demand. The file is usually append-only but will be truncated if repo
     modification is detected.
     The record for each revision contains the first 4 bytes of the
     corresponding node hash, and the record is only used if it still matches.
     Even a completely trashed rbc-revs fill thus still give the right result
     while converging towards full recovery ... assuming no incorrectly matching
     node hashes.
     The record also contains 4 bytes where 31 bits contains the index of the
     branch and the last bit indicate that it is a branch close commit.
     The usage pattern for rbc-revs is thus somewhat similar to 00changelog.i
     and will grow with it but be 1/8th of its size.
     """
 
     def __init__(self, repo, readonly=True):
         assert repo.filtername is None
         self._repo = repo
         self._names = [] # branch names in local encoding with static index
         self._rbcrevs = bytearray()
         self._rbcsnameslen = 0 # length of names read at _rbcsnameslen
         try:
             bndata = repo.vfs.read(_rbcnames)
             self._rbcsnameslen = len(bndata) # for verification before writing
             if bndata:
                 self._names = [encoding.tolocal(bn)
                                for bn in bndata.split('\0')]
         except (IOError, OSError):
             if readonly:
                 # don't try to use cache - fall back to the slow path
                 self.branchinfo = self._branchinfo
 
         if self._names:
             try:
                 data = repo.vfs.read(_rbcrevs)
                 self._rbcrevs[:] = data
             except (IOError, OSError) as inst:
                 repo.ui.debug("couldn't read revision branch cache: %s\n" %
                               inst)
         # remember number of good records on disk
         self._rbcrevslen = min(len(self._rbcrevs) // _rbcrecsize,
                                len(repo.changelog))
         if self._rbcrevslen == 0:
             self._names = []
         self._rbcnamescount = len(self._names) # number of names read at
                                                # _rbcsnameslen
         self._namesreverse = dict((b, r) for r, b in enumerate(self._names))
 
     def _clear(self):
         self._rbcsnameslen = 0
         del self._names[:]
         self._rbcnamescount = 0
         self._namesreverse.clear()
         self._rbcrevslen = len(self._repo.changelog)
         self._rbcrevs = bytearray(self._rbcrevslen * _rbcrecsize)
 
     def branchinfo(self, rev):
         """Return branch name and close flag for rev, using and updating
         persistent cache."""
         changelog = self._repo.changelog
         rbcrevidx = rev * _rbcrecsize
 
         # avoid negative index, changelog.read(nullrev) is fast without cache
         if rev == nullrev:
             return changelog.branchinfo(rev)
 
         # if requested rev isn't allocated, grow and cache the rev info
         if len(self._rbcrevs) < rbcrevidx + _rbcrecsize:
             return self._branchinfo(rev)
 
         # fast path: extract data from cache, use it if node is matching
         reponode = changelog.node(rev)[:_rbcnodelen]
         cachenode, branchidx = unpack_from(
             _rbcrecfmt, util.buffer(self._rbcrevs), rbcrevidx)
         close = bool(branchidx & _rbccloseflag)
         if close:
             branchidx &= _rbcbranchidxmask
         if cachenode == '\0\0\0\0':
             pass
         elif cachenode == reponode:
             try:
                 return self._names[branchidx], close
             except IndexError:
                 # recover from invalid reference to unknown branch
                 self._repo.ui.debug("referenced branch names not found"
                     " - rebuilding revision branch cache from scratch\n")
                 self._clear()
         else:
             # rev/node map has changed, invalidate the cache from here up
             self._repo.ui.debug("history modification detected - truncating "
                 "revision branch cache to revision %d\n" % rev)
             truncate = rbcrevidx + _rbcrecsize
             del self._rbcrevs[truncate:]
             self._rbcrevslen = min(self._rbcrevslen, truncate)
 
         # fall back to slow path and make sure it will be written to disk
         return self._branchinfo(rev)
 
     def _branchinfo(self, rev):
         """Retrieve branch info from changelog and update _rbcrevs"""
         changelog = self._repo.changelog
         b, close = changelog.branchinfo(rev)
         if b in self._namesreverse:
             branchidx = self._namesreverse[b]
         else:
             branchidx = len(self._names)
             self._names.append(b)
             self._namesreverse[b] = branchidx
         reponode = changelog.node(rev)
         if close:
             branchidx |= _rbccloseflag
         self._setcachedata(rev, reponode, branchidx)
         return b, close
 
     def _setcachedata(self, rev, node, branchidx):
         """Writes the node's branch data to the in-memory cache data."""
         if rev == nullrev:
             return
         rbcrevidx = rev * _rbcrecsize
         if len(self._rbcrevs) < rbcrevidx + _rbcrecsize:
             self._rbcrevs.extend('\0' *
                                  (len(self._repo.changelog) * _rbcrecsize -
                                   len(self._rbcrevs)))
         pack_into(_rbcrecfmt, self._rbcrevs, rbcrevidx, node, branchidx)
         self._rbcrevslen = min(self._rbcrevslen, rev)
 
         tr = self._repo.currenttransaction()
         if tr:
             tr.addfinalize('write-revbranchcache', self.write)
 
     def write(self, tr=None):
         """Save branch cache if it is dirty."""
         repo = self._repo
         wlock = None
         step = ''
         try:
             if self._rbcnamescount < len(self._names):
                 step = ' names'
                 wlock = repo.wlock(wait=False)
                 if self._rbcnamescount != 0:
                     f = repo.vfs.open(_rbcnames, 'ab')
                     if f.tell() == self._rbcsnameslen:
                         f.write('\0')
                     else:
                         f.close()
                         repo.ui.debug("%s changed - rewriting it\n" % _rbcnames)
                         self._rbcnamescount = 0
                         self._rbcrevslen = 0
                 if self._rbcnamescount == 0:
                     # before rewriting names, make sure references are removed
                     repo.vfs.unlinkpath(_rbcrevs, ignoremissing=True)
                     f = repo.vfs.open(_rbcnames, 'wb')
                 f.write('\0'.join(encoding.fromlocal(b)
                                   for b in self._names[self._rbcnamescount:]))
                 self._rbcsnameslen = f.tell()
                 f.close()
                 self._rbcnamescount = len(self._names)
 
             start = self._rbcrevslen * _rbcrecsize
             if start != len(self._rbcrevs):
                 step = ''
                 if wlock is None:
                     wlock = repo.wlock(wait=False)
                 revs = min(len(repo.changelog),
                            len(self._rbcrevs) // _rbcrecsize)
                 f = repo.vfs.open(_rbcrevs, 'ab')
                 if f.tell() != start:
                     repo.ui.debug("truncating %s to %d\n" % (_rbcrevs, start))
                     f.seek(start)
                     if f.tell() != start:
                         start = 0
                         f.seek(start)
                     f.truncate()
                 end = revs * _rbcrecsize
                 f.write(self._rbcrevs[start:end])
                 f.close()
                 self._rbcrevslen = revs
         except (IOError, OSError, error.Abort, error.LockError) as inst:
             repo.ui.debug("couldn't write revision branch cache%s: %s\n"
                           % (step, inst))
         finally:
             if wlock is not None:
                 wlock.release()

mercurial/extensions.py

@@ -1,558 +1,556 b''
 # extensions.py - extension handling for mercurial
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import imp
 import inspect
 import os
 
 from .i18n import (
     _,
     gettext,
 )
 
 from . import (
     cmdutil,
     encoding,
     error,
     pycompat,
     util,
 )
 
 _extensions = {}
 _disabledextensions = {}
 _aftercallbacks = {}
 _order = []
 _builtin = set(['hbisect', 'bookmarks', 'parentrevspec', 'progress', 'interhg',
                 'inotify', 'hgcia'])
 
 def extensions(ui=None):
     if ui:
         def enabled(name):
             for format in ['%s', 'hgext.%s']:
                 conf = ui.config('extensions', format % name)
                 if conf is not None and not conf.startswith('!'):
                     return True
     else:
         enabled = lambda name: True
     for name in _order:
         module = _extensions[name]
         if module and enabled(name):
             yield name, module
 
 def find(name):
     '''return module with given extension name'''
     mod = None
     try:
         mod = _extensions[name]
     except KeyError:
         for k, v in _extensions.iteritems():
             if k.endswith('.' + name) or k.endswith('/' + name):
                 mod = v
                 break
     if not mod:
         raise KeyError(name)
     return mod
 
 def loadpath(path, module_name):
     module_name = module_name.replace('.', '_')
     path = util.normpath(util.expandpath(path))
     module_name = pycompat.fsdecode(module_name)
     path = pycompat.fsdecode(path)
     if os.path.isdir(path):
         # module/__init__.py style
         d, f = os.path.split(path)
         fd, fpath, desc = imp.find_module(f, [d])
         return imp.load_module(module_name, fd, fpath, desc)
     else:
         try:
             return imp.load_source(module_name, path)
         except IOError as exc:
             if not exc.filename:
                 exc.filename = path # python does not fill this
             raise
 
 def _importh(name):
     """import and return the <name> module"""
     mod = __import__(pycompat.sysstr(name))
     components = name.split('.')
     for comp in components[1:]:
         mod = getattr(mod, comp)
     return mod
 
 def _importext(name, path=None, reportfunc=None):
     if path:
         # the module will be loaded in sys.modules
         # choose an unique name so that it doesn't
         # conflicts with other modules
         mod = loadpath(path, 'hgext.%s' % name)
     else:
         try:
             mod = _importh("hgext.%s" % name)
         except ImportError as err:
             if reportfunc:
                 reportfunc(err, "hgext.%s" % name, "hgext3rd.%s" % name)
             try:
                 mod = _importh("hgext3rd.%s" % name)
             except ImportError as err:
                 if reportfunc:
                     reportfunc(err, "hgext3rd.%s" % name, name)
                 mod = _importh(name)
     return mod
 
 def _forbytes(inst):
     """Portably format an import error into a form suitable for
     %-formatting into bytestrings."""
     return encoding.strtolocal(str(inst))
 
 def _reportimporterror(ui, err, failed, next):
     # note: this ui.debug happens before --debug is processed,
     #       Use --config ui.debug=1 to see them.
     ui.debug('could not import %s (%s): trying %s\n'
              % (failed, _forbytes(err), next))
     if ui.debugflag:
         ui.traceback()
 
 def load(ui, name, path):
     if name.startswith('hgext.') or name.startswith('hgext/'):
         shortname = name[6:]
     else:
         shortname = name
     if shortname in _builtin:
         return None
     if shortname in _extensions:
         return _extensions[shortname]
     _extensions[shortname] = None
     mod = _importext(name, path, bind(_reportimporterror, ui))
 
     # Before we do anything with the extension, check against minimum stated
     # compatibility. This gives extension authors a mechanism to have their
     # extensions short circuit when loaded with a known incompatible version
     # of Mercurial.
     minver = getattr(mod, 'minimumhgversion', None)
     if minver and util.versiontuple(minver, 2) > util.versiontuple(n=2):
         ui.warn(_('(third party extension %s requires version %s or newer '
                   'of Mercurial; disabling)\n') % (shortname, minver))
         return
 
     _extensions[shortname] = mod
     _order.append(shortname)
     for fn in _aftercallbacks.get(shortname, []):
         fn(loaded=True)
     return mod
 
 def _runuisetup(name, ui):
     uisetup = getattr(_extensions[name], 'uisetup', None)
     if uisetup:
         uisetup(ui)
 
 def _runextsetup(name, ui):
     extsetup = getattr(_extensions[name], 'extsetup', None)
     if extsetup:
         try:
             extsetup(ui)
         except TypeError:
             if inspect.getargspec(extsetup).args:
                 raise
             extsetup() # old extsetup with no ui argument
 
 def loadall(ui):
     result = ui.configitems("extensions")
     newindex = len(_order)
     for (name, path) in result:
         if path:
             if path[0:1] == '!':
                 _disabledextensions[name] = path[1:]
                 continue
         try:
             load(ui, name, path)
-        except KeyboardInterrupt:
-            raise
         except Exception as inst:
             inst = _forbytes(inst)
             if path:
                 ui.warn(_("*** failed to import extension %s from %s: %s\n")
                         % (name, path, inst))
             else:
                 ui.warn(_("*** failed to import extension %s: %s\n")
                         % (name, inst))
             ui.traceback()
 
     for name in _order[newindex:]:
         _runuisetup(name, ui)
 
     for name in _order[newindex:]:
         _runextsetup(name, ui)
 
     # Call aftercallbacks that were never met.
     for shortname in _aftercallbacks:
         if shortname in _extensions:
             continue
 
         for fn in _aftercallbacks[shortname]:
             fn(loaded=False)
 
     # loadall() is called multiple times and lingering _aftercallbacks
     # entries could result in double execution. See issue4646.
     _aftercallbacks.clear()
 
 def afterloaded(extension, callback):
     '''Run the specified function after a named extension is loaded.
 
     If the named extension is already loaded, the callback will be called
     immediately.
 
     If the named extension never loads, the callback will be called after
     all extensions have been loaded.
 
     The callback receives the named argument ``loaded``, which is a boolean
     indicating whether the dependent extension actually loaded.
     '''
 
     if extension in _extensions:
         callback(loaded=True)
     else:
         _aftercallbacks.setdefault(extension, []).append(callback)
 
 def bind(func, *args):
     '''Partial function application
 
       Returns a new function that is the partial application of args and kwargs
       to func.  For example,
 
           f(1, 2, bar=3) === bind(f, 1)(2, bar=3)'''
     assert callable(func)
     def closure(*a, **kw):
         return func(*(args + a), **kw)
     return closure
 
 def _updatewrapper(wrap, origfn, unboundwrapper):
     '''Copy and add some useful attributes to wrapper'''
     wrap.__module__ = getattr(origfn, '__module__')
     wrap.__doc__ = getattr(origfn, '__doc__')
     wrap.__dict__.update(getattr(origfn, '__dict__', {}))
     wrap._origfunc = origfn
     wrap._unboundwrapper = unboundwrapper
 
 def wrapcommand(table, command, wrapper, synopsis=None, docstring=None):
     '''Wrap the command named `command' in table
 
     Replace command in the command table with wrapper. The wrapped command will
     be inserted into the command table specified by the table argument.
 
     The wrapper will be called like
 
       wrapper(orig, *args, **kwargs)
 
     where orig is the original (wrapped) function, and *args, **kwargs
     are the arguments passed to it.
 
     Optionally append to the command synopsis and docstring, used for help.
     For example, if your extension wraps the ``bookmarks`` command to add the
     flags ``--remote`` and ``--all`` you might call this function like so:
 
       synopsis = ' [-a] [--remote]'
       docstring = """
 
       The ``remotenames`` extension adds the ``--remote`` and ``--all`` (``-a``)
       flags to the bookmarks command. Either flag will show the remote bookmarks
       known to the repository; ``--remote`` will also suppress the output of the
       local bookmarks.
       """
 
       extensions.wrapcommand(commands.table, 'bookmarks', exbookmarks,
                              synopsis, docstring)
     '''
     assert callable(wrapper)
     aliases, entry = cmdutil.findcmd(command, table)
     for alias, e in table.iteritems():
         if e is entry:
             key = alias
             break
 
     origfn = entry[0]
     wrap = bind(util.checksignature(wrapper), util.checksignature(origfn))
     _updatewrapper(wrap, origfn, wrapper)
     if docstring is not None:
         wrap.__doc__ += docstring
 
     newentry = list(entry)
     newentry[0] = wrap
     if synopsis is not None:
         newentry[2] += synopsis
     table[key] = tuple(newentry)
     return entry
 
 def wrapfunction(container, funcname, wrapper):
     '''Wrap the function named funcname in container
 
     Replace the funcname member in the given container with the specified
     wrapper. The container is typically a module, class, or instance.
 
     The wrapper will be called like
 
       wrapper(orig, *args, **kwargs)
 
     where orig is the original (wrapped) function, and *args, **kwargs
     are the arguments passed to it.
 
     Wrapping methods of the repository object is not recommended since
     it conflicts with extensions that extend the repository by
     subclassing. All extensions that need to extend methods of
     localrepository should use this subclassing trick: namely,
     reposetup() should look like
 
       def reposetup(ui, repo):
           class myrepo(repo.__class__):
               def whatever(self, *args, **kwargs):
                   [...extension stuff...]
                   super(myrepo, self).whatever(*args, **kwargs)
                   [...extension stuff...]
 
           repo.__class__ = myrepo
 
     In general, combining wrapfunction() with subclassing does not
     work. Since you cannot control what other extensions are loaded by
     your end users, you should play nicely with others by using the
     subclass trick.
     '''
     assert callable(wrapper)
 
     origfn = getattr(container, funcname)
     assert callable(origfn)
     wrap = bind(wrapper, origfn)
     _updatewrapper(wrap, origfn, wrapper)
     setattr(container, funcname, wrap)
     return origfn
 
 def unwrapfunction(container, funcname, wrapper=None):
     '''undo wrapfunction
 
     If wrappers is None, undo the last wrap. Otherwise removes the wrapper
     from the chain of wrappers.
 
     Return the removed wrapper.
     Raise IndexError if wrapper is None and nothing to unwrap; ValueError if
     wrapper is not None but is not found in the wrapper chain.
     '''
     chain = getwrapperchain(container, funcname)
     origfn = chain.pop()
     if wrapper is None:
         wrapper = chain[0]
     chain.remove(wrapper)
     setattr(container, funcname, origfn)
     for w in reversed(chain):
         wrapfunction(container, funcname, w)
     return wrapper
 
 def getwrapperchain(container, funcname):
     '''get a chain of wrappers of a function
 
     Return a list of functions: [newest wrapper, ..., oldest wrapper, origfunc]
 
     The wrapper functions are the ones passed to wrapfunction, whose first
     argument is origfunc.
     '''
     result = []
     fn = getattr(container, funcname)
     while fn:
         assert callable(fn)
         result.append(getattr(fn, '_unboundwrapper', fn))
         fn = getattr(fn, '_origfunc', None)
     return result
 
 def _disabledpaths(strip_init=False):
     '''find paths of disabled extensions. returns a dict of {name: path}
     removes /__init__.py from packages if strip_init is True'''
     import hgext
     extpath = os.path.dirname(
         os.path.abspath(pycompat.fsencode(hgext.__file__)))
     try: # might not be a filesystem path
         files = os.listdir(extpath)
     except OSError:
         return {}
 
     exts = {}
     for e in files:
         if e.endswith('.py'):
             name = e.rsplit('.', 1)[0]
             path = os.path.join(extpath, e)
         else:
             name = e
             path = os.path.join(extpath, e, '__init__.py')
             if not os.path.exists(path):
                 continue
             if strip_init:
                 path = os.path.dirname(path)
         if name in exts or name in _order or name == '__init__':
             continue
         exts[name] = path
     exts.update(_disabledextensions)
     return exts
 
 def _moduledoc(file):
     '''return the top-level python documentation for the given file
 
     Loosely inspired by pydoc.source_synopsis(), but rewritten to
     handle triple quotes and to return the whole text instead of just
     the synopsis'''
     result = []
 
     line = file.readline()
     while line[:1] == '#' or not line.strip():
         line = file.readline()
         if not line:
             break
 
     start = line[:3]
     if start == '"""' or start == "'''":
         line = line[3:]
         while line:
             if line.rstrip().endswith(start):
                 line = line.split(start)[0]
                 if line:
                     result.append(line)
                 break
             elif not line:
                 return None # unmatched delimiter
             result.append(line)
             line = file.readline()
     else:
         return None
 
     return ''.join(result)
 
 def _disabledhelp(path):
     '''retrieve help synopsis of a disabled extension (without importing)'''
     try:
         file = open(path)
     except IOError:
         return
     else:
         doc = _moduledoc(file)
         file.close()
 
     if doc: # extracting localized synopsis
         return gettext(doc)
     else:
         return _('(no help text available)')
 
 def disabled():
     '''find disabled extensions from hgext. returns a dict of {name: desc}'''
     try:
         from hgext import __index__
         return dict((name, gettext(desc))
                     for name, desc in __index__.docs.iteritems()
                     if name not in _order)
     except (ImportError, AttributeError):
         pass
 
     paths = _disabledpaths()
     if not paths:
         return {}
 
     exts = {}
     for name, path in paths.iteritems():
         doc = _disabledhelp(path)
         if doc:
             exts[name] = doc.splitlines()[0]
 
     return exts
 
 def disabledext(name):
     '''find a specific disabled extension from hgext. returns desc'''
     try:
         from hgext import __index__
         if name in _order:  # enabled
             return
         else:
             return gettext(__index__.docs.get(name))
     except (ImportError, AttributeError):
         pass
 
     paths = _disabledpaths()
     if name in paths:
         return _disabledhelp(paths[name])
 
 def disabledcmd(ui, cmd, strict=False):
     '''import disabled extensions until cmd is found.
     returns (cmdname, extname, module)'''
 
     paths = _disabledpaths(strip_init=True)
     if not paths:
         raise error.UnknownCommand(cmd)
 
     def findcmd(cmd, name, path):
         try:
             mod = loadpath(path, 'hgext.%s' % name)
         except Exception:
             return
         try:
             aliases, entry = cmdutil.findcmd(cmd,
                 getattr(mod, 'cmdtable', {}), strict)
         except (error.AmbiguousCommand, error.UnknownCommand):
             return
         except Exception:
             ui.warn(_('warning: error finding commands in %s\n') % path)
             ui.traceback()
             return
         for c in aliases:
             if c.startswith(cmd):
                 cmd = c
                 break
         else:
             cmd = aliases[0]
         return (cmd, name, mod)
 
     ext = None
     # first, search for an extension with the same name as the command
     path = paths.pop(cmd, None)
     if path:
         ext = findcmd(cmd, cmd, path)
     if not ext:
         # otherwise, interrogate each extension until there's a match
         for name, path in paths.iteritems():
             ext = findcmd(cmd, name, path)
             if ext:
                 break
     if ext and 'DEPRECATED' not in ext.__doc__:
         return ext
 
     raise error.UnknownCommand(cmd)
 
 def enabled(shortname=True):
     '''return a dict of {name: desc} of extensions'''
     exts = {}
     for ename, ext in extensions():
         doc = (gettext(ext.__doc__) or _('(no help text available)'))
         if shortname:
             ename = ename.split('.')[-1]
         exts[ename] = doc.splitlines()[0].strip()
 
     return exts
 
 def notloaded():
     '''return short names of extensions that failed to load'''
     return [name for name, mod in _extensions.iteritems() if mod is None]
 
 def moduleversion(module):
     '''return version information from given module as a string'''
     if (util.safehasattr(module, 'getversion')
           and callable(module.getversion)):
         version = module.getversion()
     elif util.safehasattr(module, '__version__'):
         version = module.__version__
     else:
         version = ''
     if isinstance(version, (list, tuple)):
         version = '.'.join(str(o) for o in version)
     return version
 
 def ismoduleinternal(module):
     exttestedwith = getattr(module, 'testedwith', None)
     return exttestedwith == "ships-with-hg-core"