addset: use the ascending argument in _iterordered

Fix a bug where fastasc and fastdesc were iterator in the same order as
self._ascending.

mercurial/revset.py

@@ -1,2875 +1,2875 b''
 # revset.py - revision set queries for mercurial
 #
 # Copyright 2010 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.
 
 import re
 import parser, util, error, discovery, hbisect, phases
 import node
 import heapq
 import match as matchmod
 import ancestor as ancestormod
 from i18n import _
 import encoding
 import obsolete as obsmod
 import pathutil
 import repoview
 
 def _revancestors(repo, revs, followfirst):
     """Like revlog.ancestors(), but supports followfirst."""
     cut = followfirst and 1 or None
     cl = repo.changelog
 
     def iterate():
         revqueue, revsnode = None, None
         h = []
 
         revs.descending()
         revqueue = util.deque(revs)
         if revqueue:
             revsnode = revqueue.popleft()
             heapq.heappush(h, -revsnode)
 
         seen = set([node.nullrev])
         while h:
             current = -heapq.heappop(h)
             if current not in seen:
                 if revsnode and current == revsnode:
                     if revqueue:
                         revsnode = revqueue.popleft()
                         heapq.heappush(h, -revsnode)
                 seen.add(current)
                 yield current
                 for parent in cl.parentrevs(current)[:cut]:
                     if parent != node.nullrev:
                         heapq.heappush(h, -parent)
 
     return _generatorset(iterate(), iterasc=False)
 
 def _revdescendants(repo, revs, followfirst):
     """Like revlog.descendants() but supports followfirst."""
     cut = followfirst and 1 or None
 
     def iterate():
         cl = repo.changelog
         first = min(revs)
         nullrev = node.nullrev
         if first == nullrev:
             # Are there nodes with a null first parent and a non-null
             # second one? Maybe. Do we care? Probably not.
             for i in cl:
                 yield i
         else:
             seen = set(revs)
             for i in cl.revs(first + 1):
                 for x in cl.parentrevs(i)[:cut]:
                     if x != nullrev and x in seen:
                         seen.add(i)
                         yield i
                         break
 
     return _generatorset(iterate(), iterasc=True)
 
 def _revsbetween(repo, roots, heads):
     """Return all paths between roots and heads, inclusive of both endpoint
     sets."""
     if not roots:
         return baseset([])
     parentrevs = repo.changelog.parentrevs
     visit = list(heads)
     reachable = set()
     seen = {}
     minroot = min(roots)
     roots = set(roots)
     # open-code the post-order traversal due to the tiny size of
     # sys.getrecursionlimit()
     while visit:
         rev = visit.pop()
         if rev in roots:
             reachable.add(rev)
         parents = parentrevs(rev)
         seen[rev] = parents
         for parent in parents:
             if parent >= minroot and parent not in seen:
                 visit.append(parent)
     if not reachable:
         return baseset([])
     for rev in sorted(seen):
         for parent in seen[rev]:
             if parent in reachable:
                 reachable.add(rev)
     return baseset(sorted(reachable))
 
 elements = {
     "(": (20, ("group", 1, ")"), ("func", 1, ")")),
     "~": (18, None, ("ancestor", 18)),
     "^": (18, None, ("parent", 18), ("parentpost", 18)),
     "-": (5, ("negate", 19), ("minus", 5)),
     "::": (17, ("dagrangepre", 17), ("dagrange", 17),
            ("dagrangepost", 17)),
     "..": (17, ("dagrangepre", 17), ("dagrange", 17),
            ("dagrangepost", 17)),
     ":": (15, ("rangepre", 15), ("range", 15), ("rangepost", 15)),
     "not": (10, ("not", 10)),
     "!": (10, ("not", 10)),
     "and": (5, None, ("and", 5)),
     "&": (5, None, ("and", 5)),
     "or": (4, None, ("or", 4)),
     "|": (4, None, ("or", 4)),
     "+": (4, None, ("or", 4)),
     ",": (2, None, ("list", 2)),
     ")": (0, None, None),
     "symbol": (0, ("symbol",), None),
     "string": (0, ("string",), None),
     "end": (0, None, None),
 }
 
 keywords = set(['and', 'or', 'not'])
 
 def tokenize(program, lookup=None):
     '''
     Parse a revset statement into a stream of tokens
 
     Check that @ is a valid unquoted token character (issue3686):
     >>> list(tokenize("@::"))
     [('symbol', '@', 0), ('::', None, 1), ('end', None, 3)]
 
     '''
 
     pos, l = 0, len(program)
     while pos < l:
         c = program[pos]
         if c.isspace(): # skip inter-token whitespace
             pass
         elif c == ':' and program[pos:pos + 2] == '::': # look ahead carefully
             yield ('::', None, pos)
             pos += 1 # skip ahead
         elif c == '.' and program[pos:pos + 2] == '..': # look ahead carefully
             yield ('..', None, pos)
             pos += 1 # skip ahead
         elif c in "():,-|&+!~^": # handle simple operators
             yield (c, None, pos)
         elif (c in '"\'' or c == 'r' and
               program[pos:pos + 2] in ("r'", 'r"')): # handle quoted strings
             if c == 'r':
                 pos += 1
                 c = program[pos]
                 decode = lambda x: x
             else:
                 decode = lambda x: x.decode('string-escape')
             pos += 1
             s = pos
             while pos < l: # find closing quote
                 d = program[pos]
                 if d == '\\': # skip over escaped characters
                     pos += 2
                     continue
                 if d == c:
                     yield ('string', decode(program[s:pos]), s)
                     break
                 pos += 1
             else:
                 raise error.ParseError(_("unterminated string"), s)
         # gather up a symbol/keyword
         elif c.isalnum() or c in '._@' or ord(c) > 127:
             s = pos
             pos += 1
             while pos < l: # find end of symbol
                 d = program[pos]
                 if not (d.isalnum() or d in "-._/@" or ord(d) > 127):
                     break
                 if d == '.' and program[pos - 1] == '.': # special case for ..
                     pos -= 1
                     break
                 pos += 1
             sym = program[s:pos]
             if sym in keywords: # operator keywords
                 yield (sym, None, s)
             elif '-' in sym:
                 # some jerk gave us foo-bar-baz, try to check if it's a symbol
                 if lookup and lookup(sym):
                     # looks like a real symbol
                     yield ('symbol', sym, s)
                 else:
                     # looks like an expression
                     parts = sym.split('-')
                     for p in parts[:-1]:
                         if p: # possible consecutive -
                             yield ('symbol', p, s)
                         s += len(p)
                         yield ('-', None, pos)
                         s += 1
                     if parts[-1]: # possible trailing -
                         yield ('symbol', parts[-1], s)
             else:
                 yield ('symbol', sym, s)
             pos -= 1
         else:
             raise error.ParseError(_("syntax error"), pos)
         pos += 1
     yield ('end', None, pos)
 
 # helpers
 
 def getstring(x, err):
     if x and (x[0] == 'string' or x[0] == 'symbol'):
         return x[1]
     raise error.ParseError(err)
 
 def getlist(x):
     if not x:
         return []
     if x[0] == 'list':
         return getlist(x[1]) + [x[2]]
     return [x]
 
 def getargs(x, min, max, err):
     l = getlist(x)
     if len(l) < min or (max >= 0 and len(l) > max):
         raise error.ParseError(err)
     return l
 
 def getset(repo, subset, x):
     if not x:
         raise error.ParseError(_("missing argument"))
     s = methods[x[0]](repo, subset, *x[1:])
     if util.safehasattr(s, 'set'):
         return s
     return baseset(s)
 
 def _getrevsource(repo, r):
     extra = repo[r].extra()
     for label in ('source', 'transplant_source', 'rebase_source'):
         if label in extra:
             try:
                 return repo[extra[label]].rev()
             except error.RepoLookupError:
                 pass
     return None
 
 # operator methods
 
 def stringset(repo, subset, x):
     x = repo[x].rev()
     if x == -1 and len(subset) == len(repo):
         return baseset([-1])
     if len(subset) == len(repo) or x in subset:
         return baseset([x])
     return baseset([])
 
 def symbolset(repo, subset, x):
     if x in symbols:
         raise error.ParseError(_("can't use %s here") % x)
     return stringset(repo, subset, x)
 
 def rangeset(repo, subset, x, y):
     cl = baseset(repo.changelog)
     m = getset(repo, cl, x)
     n = getset(repo, cl, y)
 
     if not m or not n:
         return baseset([])
     m, n = m[0], n[-1]
 
     if m < n:
         r = spanset(repo, m, n + 1)
     else:
         r = spanset(repo, m, n - 1)
     return r & subset
 
 def dagrange(repo, subset, x, y):
     r = spanset(repo)
     xs = _revsbetween(repo, getset(repo, r, x), getset(repo, r, y))
     s = subset.set()
     return xs.filter(s.__contains__)
 
 def andset(repo, subset, x, y):
     return getset(repo, getset(repo, subset, x), y)
 
 def orset(repo, subset, x, y):
     xl = getset(repo, subset, x)
     yl = getset(repo, subset - xl, y)
     return xl + yl
 
 def notset(repo, subset, x):
     return subset - getset(repo, subset, x)
 
 def listset(repo, subset, a, b):
     raise error.ParseError(_("can't use a list in this context"))
 
 def func(repo, subset, a, b):
     if a[0] == 'symbol' and a[1] in symbols:
         return symbols[a[1]](repo, subset, b)
     raise error.ParseError(_("not a function: %s") % a[1])
 
 # functions
 
 def adds(repo, subset, x):
     """``adds(pattern)``
     Changesets that add a file matching pattern.
 
     The pattern without explicit kind like ``glob:`` is expected to be
     relative to the current directory and match against a file or a
     directory.
     """
     # i18n: "adds" is a keyword
     pat = getstring(x, _("adds requires a pattern"))
     return checkstatus(repo, subset, pat, 1)
 
 def ancestor(repo, subset, x):
     """``ancestor(*changeset)``
     A greatest common ancestor of the changesets.
 
     Accepts 0 or more changesets.
     Will return empty list when passed no args.
     Greatest common ancestor of a single changeset is that changeset.
     """
     # i18n: "ancestor" is a keyword
     l = getlist(x)
     rl = spanset(repo)
     anc = None
 
     # (getset(repo, rl, i) for i in l) generates a list of lists
     for revs in (getset(repo, rl, i) for i in l):
         for r in revs:
             if anc is None:
                 anc = repo[r]
             else:
                 anc = anc.ancestor(repo[r])
 
     if anc is not None and anc.rev() in subset:
         return baseset([anc.rev()])
     return baseset([])
 
 def _ancestors(repo, subset, x, followfirst=False):
     args = getset(repo, spanset(repo), x)
     if not args:
         return baseset([])
     s = _revancestors(repo, args, followfirst)
     return subset.filter(s.__contains__)
 
 def ancestors(repo, subset, x):
     """``ancestors(set)``
     Changesets that are ancestors of a changeset in set.
     """
     return _ancestors(repo, subset, x)
 
 def _firstancestors(repo, subset, x):
     # ``_firstancestors(set)``
     # Like ``ancestors(set)`` but follows only the first parents.
     return _ancestors(repo, subset, x, followfirst=True)
 
 def ancestorspec(repo, subset, x, n):
     """``set~n``
     Changesets that are the Nth ancestor (first parents only) of a changeset
     in set.
     """
     try:
         n = int(n[1])
     except (TypeError, ValueError):
         raise error.ParseError(_("~ expects a number"))
     ps = set()
     cl = repo.changelog
     for r in getset(repo, baseset(cl), x):
         for i in range(n):
             r = cl.parentrevs(r)[0]
         ps.add(r)
     return subset & ps
 
 def author(repo, subset, x):
     """``author(string)``
     Alias for ``user(string)``.
     """
     # i18n: "author" is a keyword
     n = encoding.lower(getstring(x, _("author requires a string")))
     kind, pattern, matcher = _substringmatcher(n)
     return subset.filter(lambda x: matcher(encoding.lower(repo[x].user())))
 
 def only(repo, subset, x):
     """``only(set, [set])``
     Changesets that are ancestors of the first set that are not ancestors
     of any other head in the repo. If a second set is specified, the result
     is ancestors of the first set that are not ancestors of the second set
     (i.e. ::<set1> - ::<set2>).
     """
     cl = repo.changelog
     # i18n: "only" is a keyword
     args = getargs(x, 1, 2, _('only takes one or two arguments'))
     include = getset(repo, spanset(repo), args[0]).set()
     if len(args) == 1:
         if len(include) == 0:
             return baseset([])
 
         descendants = set(_revdescendants(repo, include, False))
         exclude = [rev for rev in cl.headrevs()
             if not rev in descendants and not rev in include]
     else:
         exclude = getset(repo, spanset(repo), args[1])
 
     results = set(ancestormod.missingancestors(include, exclude, cl.parentrevs))
     return filteredset(subset, results.__contains__)
 
 def bisect(repo, subset, x):
     """``bisect(string)``
     Changesets marked in the specified bisect status:
 
     - ``good``, ``bad``, ``skip``: csets explicitly marked as good/bad/skip
     - ``goods``, ``bads``      : csets topologically good/bad
     - ``range``              : csets taking part in the bisection
     - ``pruned``             : csets that are goods, bads or skipped
     - ``untested``           : csets whose fate is yet unknown
     - ``ignored``            : csets ignored due to DAG topology
     - ``current``            : the cset currently being bisected
     """
     # i18n: "bisect" is a keyword
     status = getstring(x, _("bisect requires a string")).lower()
     state = set(hbisect.get(repo, status))
     return subset & state
 
 # Backward-compatibility
 # - no help entry so that we do not advertise it any more
 def bisected(repo, subset, x):
     return bisect(repo, subset, x)
 
 def bookmark(repo, subset, x):
     """``bookmark([name])``
     The named bookmark or all bookmarks.
 
     If `name` starts with `re:`, the remainder of the name is treated as
     a regular expression. To match a bookmark that actually starts with `re:`,
     use the prefix `literal:`.
     """
     # i18n: "bookmark" is a keyword
     args = getargs(x, 0, 1, _('bookmark takes one or no arguments'))
     if args:
         bm = getstring(args[0],
                        # i18n: "bookmark" is a keyword
                        _('the argument to bookmark must be a string'))
         kind, pattern, matcher = _stringmatcher(bm)
         bms = set()
         if kind == 'literal':
             bmrev = repo._bookmarks.get(pattern, None)
             if not bmrev:
                 raise util.Abort(_("bookmark '%s' does not exist") % bm)
             bms.add(repo[bmrev].rev())
         else:
             matchrevs = set()
             for name, bmrev in repo._bookmarks.iteritems():
                 if matcher(name):
                     matchrevs.add(bmrev)
             if not matchrevs:
                 raise util.Abort(_("no bookmarks exist that match '%s'")
                                  % pattern)
             for bmrev in matchrevs:
                 bms.add(repo[bmrev].rev())
     else:
         bms = set([repo[r].rev()
                    for r in repo._bookmarks.values()])
     bms -= set([node.nullrev])
     return subset & bms
 
 def branch(repo, subset, x):
     """``branch(string or set)``
     All changesets belonging to the given branch or the branches of the given
     changesets.
 
     If `string` starts with `re:`, the remainder of the name is treated as
     a regular expression. To match a branch that actually starts with `re:`,
     use the prefix `literal:`.
     """
     try:
         b = getstring(x, '')
     except error.ParseError:
         # not a string, but another revspec, e.g. tip()
         pass
     else:
         kind, pattern, matcher = _stringmatcher(b)
         if kind == 'literal':
             # note: falls through to the revspec case if no branch with
             # this name exists
             if pattern in repo.branchmap():
                 return subset.filter(lambda r: matcher(repo[r].branch()))
         else:
             return subset.filter(lambda r: matcher(repo[r].branch()))
 
     s = getset(repo, spanset(repo), x)
     b = set()
     for r in s:
         b.add(repo[r].branch())
     s = s.set()
     return subset.filter(lambda r: r in s or repo[r].branch() in b)
 
 def bumped(repo, subset, x):
     """``bumped()``
     Mutable changesets marked as successors of public changesets.
 
     Only non-public and non-obsolete changesets can be `bumped`.
     """
     # i18n: "bumped" is a keyword
     getargs(x, 0, 0, _("bumped takes no arguments"))
     bumped = obsmod.getrevs(repo, 'bumped')
     return subset & bumped
 
 def bundle(repo, subset, x):
     """``bundle()``
     Changesets in the bundle.
 
     Bundle must be specified by the -R option."""
 
     try:
         bundlerevs = repo.changelog.bundlerevs
     except AttributeError:
         raise util.Abort(_("no bundle provided - specify with -R"))
     return subset & bundlerevs
 
 def checkstatus(repo, subset, pat, field):
     hasset = matchmod.patkind(pat) == 'set'
 
     def matches(x):
         m = None
         fname = None
         c = repo[x]
         if not m or hasset:
             m = matchmod.match(repo.root, repo.getcwd(), [pat], ctx=c)
             if not m.anypats() and len(m.files()) == 1:
                 fname = m.files()[0]
         if fname is not None:
             if fname not in c.files():
                 return False
         else:
             for f in c.files():
                 if m(f):
                     break
             else:
                 return False
         files = repo.status(c.p1().node(), c.node())[field]
         if fname is not None:
             if fname in files:
                 return True
         else:
             for f in files:
                 if m(f):
                     return True
 
     return subset.filter(matches)
 
 def _children(repo, narrow, parentset):
     cs = set()
     if not parentset:
         return baseset(cs)
     pr = repo.changelog.parentrevs
     minrev = min(parentset)
     for r in narrow:
         if r <= minrev:
             continue
         for p in pr(r):
             if p in parentset:
                 cs.add(r)
     return baseset(cs)
 
 def children(repo, subset, x):
     """``children(set)``
     Child changesets of changesets in set.
     """
     s = getset(repo, baseset(repo), x).set()
     cs = _children(repo, subset, s)
     return subset & cs
 
 def closed(repo, subset, x):
     """``closed()``
     Changeset is closed.
     """
     # i18n: "closed" is a keyword
     getargs(x, 0, 0, _("closed takes no arguments"))
     return subset.filter(lambda r: repo[r].closesbranch())
 
 def contains(repo, subset, x):
     """``contains(pattern)``
     The revision's manifest contains a file matching pattern (but might not
     modify it). See :hg:`help patterns` for information about file patterns.
 
     The pattern without explicit kind like ``glob:`` is expected to be
     relative to the current directory and match against a file exactly
     for efficiency.
     """
     # i18n: "contains" is a keyword
     pat = getstring(x, _("contains requires a pattern"))
 
     def matches(x):
         if not matchmod.patkind(pat):
             pats = pathutil.canonpath(repo.root, repo.getcwd(), pat)
             if pats in repo[x]:
                 return True
         else:
             c = repo[x]
             m = matchmod.match(repo.root, repo.getcwd(), [pat], ctx=c)
             for f in c.manifest():
                 if m(f):
                     return True
         return False
 
     return subset.filter(matches)
 
 def converted(repo, subset, x):
     """``converted([id])``
     Changesets converted from the given identifier in the old repository if
     present, or all converted changesets if no identifier is specified.
     """
 
     # There is exactly no chance of resolving the revision, so do a simple
     # string compare and hope for the best
 
     rev = None
     # i18n: "converted" is a keyword
     l = getargs(x, 0, 1, _('converted takes one or no arguments'))
     if l:
         # i18n: "converted" is a keyword
         rev = getstring(l[0], _('converted requires a revision'))
 
     def _matchvalue(r):
         source = repo[r].extra().get('convert_revision', None)
         return source is not None and (rev is None or source.startswith(rev))
 
     return subset.filter(lambda r: _matchvalue(r))
 
 def date(repo, subset, x):
     """``date(interval)``
     Changesets within the interval, see :hg:`help dates`.
     """
     # i18n: "date" is a keyword
     ds = getstring(x, _("date requires a string"))
     dm = util.matchdate(ds)
     return subset.filter(lambda x: dm(repo[x].date()[0]))
 
 def desc(repo, subset, x):
     """``desc(string)``
     Search commit message for string. The match is case-insensitive.
     """
     # i18n: "desc" is a keyword
     ds = encoding.lower(getstring(x, _("desc requires a string")))
 
     def matches(x):
         c = repo[x]
         return ds in encoding.lower(c.description())
 
     return subset.filter(matches)
 
 def _descendants(repo, subset, x, followfirst=False):
     args = getset(repo, spanset(repo), x)
     if not args:
         return baseset([])
     s = _revdescendants(repo, args, followfirst)
 
     # Both sets need to be ascending in order to lazily return the union
     # in the correct order.
     args.ascending()
     result = (filteredset(s, subset.__contains__, ascending=True) +
               filteredset(args, subset.__contains__, ascending=True))
 
     # Wrap result in a filteredset since it's an _addset, which doesn't
     # implement all the necessary functions to be consumed by callers.
     return filteredset(result, lambda r: True, ascending=True)
 
 def descendants(repo, subset, x):
     """``descendants(set)``
     Changesets which are descendants of changesets in set.
     """
     return _descendants(repo, subset, x)
 
 def _firstdescendants(repo, subset, x):
     # ``_firstdescendants(set)``
     # Like ``descendants(set)`` but follows only the first parents.
     return _descendants(repo, subset, x, followfirst=True)
 
 def destination(repo, subset, x):
     """``destination([set])``
     Changesets that were created by a graft, transplant or rebase operation,
     with the given revisions specified as the source.  Omitting the optional set
     is the same as passing all().
     """
     if x is not None:
         args = getset(repo, spanset(repo), x).set()
     else:
         args = getall(repo, spanset(repo), x).set()
 
     dests = set()
 
     # subset contains all of the possible destinations that can be returned, so
     # iterate over them and see if their source(s) were provided in the args.
     # Even if the immediate src of r is not in the args, src's source (or
     # further back) may be.  Scanning back further than the immediate src allows
     # transitive transplants and rebases to yield the same results as transitive
     # grafts.
     for r in subset:
         src = _getrevsource(repo, r)
         lineage = None
 
         while src is not None:
             if lineage is None:
                 lineage = list()
 
             lineage.append(r)
 
             # The visited lineage is a match if the current source is in the arg
             # set.  Since every candidate dest is visited by way of iterating
             # subset, any dests further back in the lineage will be tested by a
             # different iteration over subset.  Likewise, if the src was already
             # selected, the current lineage can be selected without going back
             # further.
             if src in args or src in dests:
                 dests.update(lineage)
                 break
 
             r = src
             src = _getrevsource(repo, r)
 
     return subset.filter(dests.__contains__)
 
 def divergent(repo, subset, x):
     """``divergent()``
     Final successors of changesets with an alternative set of final successors.
     """
     # i18n: "divergent" is a keyword
     getargs(x, 0, 0, _("divergent takes no arguments"))
     divergent = obsmod.getrevs(repo, 'divergent')
     return subset & divergent
 
 def draft(repo, subset, x):
     """``draft()``
     Changeset in draft phase."""
     # i18n: "draft" is a keyword
     getargs(x, 0, 0, _("draft takes no arguments"))
     pc = repo._phasecache
     return subset.filter(lambda r: pc.phase(repo, r) == phases.draft)
 
 def extinct(repo, subset, x):
     """``extinct()``
     Obsolete changesets with obsolete descendants only.
     """
     # i18n: "extinct" is a keyword
     getargs(x, 0, 0, _("extinct takes no arguments"))
     extincts = obsmod.getrevs(repo, 'extinct')
     return subset & extincts
 
 def extra(repo, subset, x):
     """``extra(label, [value])``
     Changesets with the given label in the extra metadata, with the given
     optional value.
 
     If `value` starts with `re:`, the remainder of the value is treated as
     a regular expression. To match a value that actually starts with `re:`,
     use the prefix `literal:`.
     """
 
     # i18n: "extra" is a keyword
     l = getargs(x, 1, 2, _('extra takes at least 1 and at most 2 arguments'))
     # i18n: "extra" is a keyword
     label = getstring(l[0], _('first argument to extra must be a string'))
     value = None
 
     if len(l) > 1:
         # i18n: "extra" is a keyword
         value = getstring(l[1], _('second argument to extra must be a string'))
         kind, value, matcher = _stringmatcher(value)
 
     def _matchvalue(r):
         extra = repo[r].extra()
         return label in extra and (value is None or matcher(extra[label]))
 
     return subset.filter(lambda r: _matchvalue(r))
 
 def filelog(repo, subset, x):
     """``filelog(pattern)``
     Changesets connected to the specified filelog.
 
     For performance reasons, visits only revisions mentioned in the file-level
     filelog, rather than filtering through all changesets (much faster, but
     doesn't include deletes or duplicate changes). For a slower, more accurate
     result, use ``file()``.
 
     The pattern without explicit kind like ``glob:`` is expected to be
     relative to the current directory and match against a file exactly
     for efficiency.
     """
 
     # i18n: "filelog" is a keyword
     pat = getstring(x, _("filelog requires a pattern"))
     s = set()
 
     if not matchmod.patkind(pat):
         f = pathutil.canonpath(repo.root, repo.getcwd(), pat)
         fl = repo.file(f)
         for fr in fl:
             s.add(fl.linkrev(fr))
     else:
         m = matchmod.match(repo.root, repo.getcwd(), [pat], ctx=repo[None])
         for f in repo[None]:
             if m(f):
                 fl = repo.file(f)
                 for fr in fl:
                     s.add(fl.linkrev(fr))
 
     return subset & s
 
 def first(repo, subset, x):
     """``first(set, [n])``
     An alias for limit().
     """
     return limit(repo, subset, x)
 
 def _follow(repo, subset, x, name, followfirst=False):
     l = getargs(x, 0, 1, _("%s takes no arguments or a filename") % name)
     c = repo['.']
     if l:
         x = getstring(l[0], _("%s expected a filename") % name)
         if x in c:
             cx = c[x]
             s = set(ctx.rev() for ctx in cx.ancestors(followfirst=followfirst))
             # include the revision responsible for the most recent version
             s.add(cx.linkrev())
         else:
             return baseset([])
     else:
         s = _revancestors(repo, baseset([c.rev()]), followfirst)
 
     return subset & s
 
 def follow(repo, subset, x):
     """``follow([file])``
     An alias for ``::.`` (ancestors of the working copy's first parent).
     If a filename is specified, the history of the given file is followed,
     including copies.
     """
     return _follow(repo, subset, x, 'follow')
 
 def _followfirst(repo, subset, x):
     # ``followfirst([file])``
     # Like ``follow([file])`` but follows only the first parent of
     # every revision or file revision.
     return _follow(repo, subset, x, '_followfirst', followfirst=True)
 
 def getall(repo, subset, x):
     """``all()``
     All changesets, the same as ``0:tip``.
     """
     # i18n: "all" is a keyword
     getargs(x, 0, 0, _("all takes no arguments"))
     return subset
 
 def grep(repo, subset, x):
     """``grep(regex)``
     Like ``keyword(string)`` but accepts a regex. Use ``grep(r'...')``
     to ensure special escape characters are handled correctly. Unlike
     ``keyword(string)``, the match is case-sensitive.
     """
     try:
         # i18n: "grep" is a keyword
         gr = re.compile(getstring(x, _("grep requires a string")))
     except re.error, e:
         raise error.ParseError(_('invalid match pattern: %s') % e)
 
     def matches(x):
         c = repo[x]
         for e in c.files() + [c.user(), c.description()]:
             if gr.search(e):
                 return True
         return False
 
     return subset.filter(matches)
 
 def _matchfiles(repo, subset, x):
     # _matchfiles takes a revset list of prefixed arguments:
     #
     #   [p:foo, i:bar, x:baz]
     #
     # builds a match object from them and filters subset. Allowed
     # prefixes are 'p:' for regular patterns, 'i:' for include
     # patterns and 'x:' for exclude patterns. Use 'r:' prefix to pass
     # a revision identifier, or the empty string to reference the
     # working directory, from which the match object is
     # initialized. Use 'd:' to set the default matching mode, default
     # to 'glob'. At most one 'r:' and 'd:' argument can be passed.
 
     # i18n: "_matchfiles" is a keyword
     l = getargs(x, 1, -1, _("_matchfiles requires at least one argument"))
     pats, inc, exc = [], [], []
     hasset = False
     rev, default = None, None
     for arg in l:
         # i18n: "_matchfiles" is a keyword
         s = getstring(arg, _("_matchfiles requires string arguments"))
         prefix, value = s[:2], s[2:]
         if prefix == 'p:':
             pats.append(value)
         elif prefix == 'i:':
             inc.append(value)
         elif prefix == 'x:':
             exc.append(value)
         elif prefix == 'r:':
             if rev is not None:
                 # i18n: "_matchfiles" is a keyword
                 raise error.ParseError(_('_matchfiles expected at most one '
                                          'revision'))
             rev = value
         elif prefix == 'd:':
             if default is not None:
                 # i18n: "_matchfiles" is a keyword
                 raise error.ParseError(_('_matchfiles expected at most one '
                                          'default mode'))
             default = value
         else:
             # i18n: "_matchfiles" is a keyword
             raise error.ParseError(_('invalid _matchfiles prefix: %s') % prefix)
         if not hasset and matchmod.patkind(value) == 'set':
             hasset = True
     if not default:
         default = 'glob'
 
     def matches(x):
         m = None
         c = repo[x]
         if not m or (hasset and rev is None):
             ctx = c
             if rev is not None:
                 ctx = repo[rev or None]
             m = matchmod.match(repo.root, repo.getcwd(), pats, include=inc,
                                exclude=exc, ctx=ctx, default=default)
         for f in c.files():
             if m(f):
                 return True
         return False
 
     return subset.filter(matches)
 
 def hasfile(repo, subset, x):
     """``file(pattern)``
     Changesets affecting files matched by pattern.
 
     For a faster but less accurate result, consider using ``filelog()``
     instead.
 
     This predicate uses ``glob:`` as the default kind of pattern.
     """
     # i18n: "file" is a keyword
     pat = getstring(x, _("file requires a pattern"))
     return _matchfiles(repo, subset, ('string', 'p:' + pat))
 
 def head(repo, subset, x):
     """``head()``
     Changeset is a named branch head.
     """
     # i18n: "head" is a keyword
     getargs(x, 0, 0, _("head takes no arguments"))
     hs = set()
     for b, ls in repo.branchmap().iteritems():
         hs.update(repo[h].rev() for h in ls)
     return baseset(hs).filter(subset.__contains__)
 
 def heads(repo, subset, x):
     """``heads(set)``
     Members of set with no children in set.
     """
     s = getset(repo, subset, x)
     ps = parents(repo, subset, x)
     return s - ps
 
 def hidden(repo, subset, x):
     """``hidden()``
     Hidden changesets.
     """
     # i18n: "hidden" is a keyword
     getargs(x, 0, 0, _("hidden takes no arguments"))
     hiddenrevs = repoview.filterrevs(repo, 'visible')
     return subset & hiddenrevs
 
 def keyword(repo, subset, x):
     """``keyword(string)``
     Search commit message, user name, and names of changed files for
     string. The match is case-insensitive.
     """
     # i18n: "keyword" is a keyword
     kw = encoding.lower(getstring(x, _("keyword requires a string")))
 
     def matches(r):
         c = repo[r]
         return util.any(kw in encoding.lower(t) for t in c.files() + [c.user(),
             c.description()])
 
     return subset.filter(matches)
 
 def limit(repo, subset, x):
     """``limit(set, [n])``
     First n members of set, defaulting to 1.
     """
     # i18n: "limit" is a keyword
     l = getargs(x, 1, 2, _("limit requires one or two arguments"))
     try:
         lim = 1
         if len(l) == 2:
             # i18n: "limit" is a keyword
             lim = int(getstring(l[1], _("limit requires a number")))
     except (TypeError, ValueError):
         # i18n: "limit" is a keyword
         raise error.ParseError(_("limit expects a number"))
     ss = subset.set()
     os = getset(repo, spanset(repo), l[0])
     bs = baseset([])
     it = iter(os)
     for x in xrange(lim):
         try:
             y = it.next()
             if y in ss:
                 bs.append(y)
         except (StopIteration):
             break
     return bs
 
 def last(repo, subset, x):
     """``last(set, [n])``
     Last n members of set, defaulting to 1.
     """
     # i18n: "last" is a keyword
     l = getargs(x, 1, 2, _("last requires one or two arguments"))
     try:
         lim = 1
         if len(l) == 2:
             # i18n: "last" is a keyword
             lim = int(getstring(l[1], _("last requires a number")))
     except (TypeError, ValueError):
         # i18n: "last" is a keyword
         raise error.ParseError(_("last expects a number"))
     ss = subset.set()
     os = getset(repo, spanset(repo), l[0])
     os.reverse()
     bs = baseset([])
     it = iter(os)
     for x in xrange(lim):
         try:
             y = it.next()
             if y in ss:
                 bs.append(y)
         except (StopIteration):
             break
     return bs
 
 def maxrev(repo, subset, x):
     """``max(set)``
     Changeset with highest revision number in set.
     """
     os = getset(repo, spanset(repo), x)
     if os:
         m = os.max()
         if m in subset:
             return baseset([m])
     return baseset([])
 
 def merge(repo, subset, x):
     """``merge()``
     Changeset is a merge changeset.
     """
     # i18n: "merge" is a keyword
     getargs(x, 0, 0, _("merge takes no arguments"))
     cl = repo.changelog
     return subset.filter(lambda r: cl.parentrevs(r)[1] != -1)
 
 def branchpoint(repo, subset, x):
     """``branchpoint()``
     Changesets with more than one child.
     """
     # i18n: "branchpoint" is a keyword
     getargs(x, 0, 0, _("branchpoint takes no arguments"))
     cl = repo.changelog
     if not subset:
         return baseset([])
     baserev = min(subset)
     parentscount = [0]*(len(repo) - baserev)
     for r in cl.revs(start=baserev + 1):
         for p in cl.parentrevs(r):
             if p >= baserev:
                 parentscount[p - baserev] += 1
     return subset.filter(lambda r: parentscount[r - baserev] > 1)
 
 def minrev(repo, subset, x):
     """``min(set)``
     Changeset with lowest revision number in set.
     """
     os = getset(repo, spanset(repo), x)
     if os:
         m = os.min()
         if m in subset:
             return baseset([m])
     return baseset([])
 
 def modifies(repo, subset, x):
     """``modifies(pattern)``
     Changesets modifying files matched by pattern.
 
     The pattern without explicit kind like ``glob:`` is expected to be
     relative to the current directory and match against a file or a
     directory.
     """
     # i18n: "modifies" is a keyword
     pat = getstring(x, _("modifies requires a pattern"))
     return checkstatus(repo, subset, pat, 0)
 
 def node_(repo, subset, x):
     """``id(string)``
     Revision non-ambiguously specified by the given hex string prefix.
     """
     # i18n: "id" is a keyword
     l = getargs(x, 1, 1, _("id requires one argument"))
     # i18n: "id" is a keyword
     n = getstring(l[0], _("id requires a string"))
     if len(n) == 40:
         rn = repo[n].rev()
     else:
         rn = None
         pm = repo.changelog._partialmatch(n)
         if pm is not None:
             rn = repo.changelog.rev(pm)
 
     return subset.filter(lambda r: r == rn)
 
 def obsolete(repo, subset, x):
     """``obsolete()``
     Mutable changeset with a newer version."""
     # i18n: "obsolete" is a keyword
     getargs(x, 0, 0, _("obsolete takes no arguments"))
     obsoletes = obsmod.getrevs(repo, 'obsolete')
     return subset & obsoletes
 
 def origin(repo, subset, x):
     """``origin([set])``
     Changesets that were specified as a source for the grafts, transplants or
     rebases that created the given revisions.  Omitting the optional set is the
     same as passing all().  If a changeset created by these operations is itself
     specified as a source for one of these operations, only the source changeset
     for the first operation is selected.
     """
     if x is not None:
         args = getset(repo, spanset(repo), x).set()
     else:
         args = getall(repo, spanset(repo), x).set()
 
     def _firstsrc(rev):
         src = _getrevsource(repo, rev)
         if src is None:
             return None
 
         while True:
             prev = _getrevsource(repo, src)
 
             if prev is None:
                 return src
             src = prev
 
     o = set([_firstsrc(r) for r in args])
     o -= set([None])
     return subset & o
 
 def outgoing(repo, subset, x):
     """``outgoing([path])``
     Changesets not found in the specified destination repository, or the
     default push location.
     """
     import hg # avoid start-up nasties
     # i18n: "outgoing" is a keyword
     l = getargs(x, 0, 1, _("outgoing takes one or no arguments"))
     # i18n: "outgoing" is a keyword
     dest = l and getstring(l[0], _("outgoing requires a repository path")) or ''
     dest = repo.ui.expandpath(dest or 'default-push', dest or 'default')
     dest, branches = hg.parseurl(dest)
     revs, checkout = hg.addbranchrevs(repo, repo, branches, [])
     if revs:
         revs = [repo.lookup(rev) for rev in revs]
     other = hg.peer(repo, {}, dest)
     repo.ui.pushbuffer()
     outgoing = discovery.findcommonoutgoing(repo, other, onlyheads=revs)
     repo.ui.popbuffer()
     cl = repo.changelog
     o = set([cl.rev(r) for r in outgoing.missing])
     return subset & o
 
 def p1(repo, subset, x):
     """``p1([set])``
     First parent of changesets in set, or the working directory.
     """
     if x is None:
         p = repo[x].p1().rev()
         if p >= 0:
             return subset & baseset([p])
         return baseset([])
 
     ps = set()
     cl = repo.changelog
     for r in getset(repo, spanset(repo), x):
         ps.add(cl.parentrevs(r)[0])
     ps -= set([node.nullrev])
     return subset & ps
 
 def p2(repo, subset, x):
     """``p2([set])``
     Second parent of changesets in set, or the working directory.
     """
     if x is None:
         ps = repo[x].parents()
         try:
             p = ps[1].rev()
             if p >= 0:
                 return subset & baseset([p])
             return baseset([])
         except IndexError:
             return baseset([])
 
     ps = set()
     cl = repo.changelog
     for r in getset(repo, spanset(repo), x):
         ps.add(cl.parentrevs(r)[1])
     ps -= set([node.nullrev])
     return subset & ps
 
 def parents(repo, subset, x):
     """``parents([set])``
     The set of all parents for all changesets in set, or the working directory.
     """
     if x is None:
         ps = set(p.rev() for p in repo[x].parents())
     else:
         ps = set()
         cl = repo.changelog
         for r in getset(repo, spanset(repo), x):
             ps.update(cl.parentrevs(r))
     ps -= set([node.nullrev])
     return subset & ps
 
 def parentspec(repo, subset, x, n):
     """``set^0``
     The set.
     ``set^1`` (or ``set^``), ``set^2``
     First or second parent, respectively, of all changesets in set.
     """
     try:
         n = int(n[1])
         if n not in (0, 1, 2):
             raise ValueError
     except (TypeError, ValueError):
         raise error.ParseError(_("^ expects a number 0, 1, or 2"))
     ps = set()
     cl = repo.changelog
     for r in getset(repo, baseset(cl), x):
         if n == 0:
             ps.add(r)
         elif n == 1:
             ps.add(cl.parentrevs(r)[0])
         elif n == 2:
             parents = cl.parentrevs(r)
             if len(parents) > 1:
                 ps.add(parents[1])
     return subset & ps
 
 def present(repo, subset, x):
     """``present(set)``
     An empty set, if any revision in set isn't found; otherwise,
     all revisions in set.
 
     If any of specified revisions is not present in the local repository,
     the query is normally aborted. But this predicate allows the query
     to continue even in such cases.
     """
     try:
         return getset(repo, subset, x)
     except error.RepoLookupError:
         return baseset([])
 
 def public(repo, subset, x):
     """``public()``
     Changeset in public phase."""
     # i18n: "public" is a keyword
     getargs(x, 0, 0, _("public takes no arguments"))
     pc = repo._phasecache
     return subset.filter(lambda r: pc.phase(repo, r) == phases.public)
 
 def remote(repo, subset, x):
     """``remote([id [,path]])``
     Local revision that corresponds to the given identifier in a
     remote repository, if present. Here, the '.' identifier is a
     synonym for the current local branch.
     """
 
     import hg # avoid start-up nasties
     # i18n: "remote" is a keyword
     l = getargs(x, 0, 2, _("remote takes one, two or no arguments"))
 
     q = '.'
     if len(l) > 0:
     # i18n: "remote" is a keyword
         q = getstring(l[0], _("remote requires a string id"))
     if q == '.':
         q = repo['.'].branch()
 
     dest = ''
     if len(l) > 1:
         # i18n: "remote" is a keyword
         dest = getstring(l[1], _("remote requires a repository path"))
     dest = repo.ui.expandpath(dest or 'default')
     dest, branches = hg.parseurl(dest)
     revs, checkout = hg.addbranchrevs(repo, repo, branches, [])
     if revs:
         revs = [repo.lookup(rev) for rev in revs]
     other = hg.peer(repo, {}, dest)
     n = other.lookup(q)
     if n in repo:
         r = repo[n].rev()
         if r in subset:
             return baseset([r])
     return baseset([])
 
 def removes(repo, subset, x):
     """``removes(pattern)``
     Changesets which remove files matching pattern.
 
     The pattern without explicit kind like ``glob:`` is expected to be
     relative to the current directory and match against a file or a
     directory.
     """
     # i18n: "removes" is a keyword
     pat = getstring(x, _("removes requires a pattern"))
     return checkstatus(repo, subset, pat, 2)
 
 def rev(repo, subset, x):
     """``rev(number)``
     Revision with the given numeric identifier.
     """
     # i18n: "rev" is a keyword
     l = getargs(x, 1, 1, _("rev requires one argument"))
     try:
         # i18n: "rev" is a keyword
         l = int(getstring(l[0], _("rev requires a number")))
     except (TypeError, ValueError):
         # i18n: "rev" is a keyword
         raise error.ParseError(_("rev expects a number"))
     return subset & baseset([l])
 
 def matching(repo, subset, x):
     """``matching(revision [, field])``
     Changesets in which a given set of fields match the set of fields in the
     selected revision or set.
 
     To match more than one field pass the list of fields to match separated
     by spaces (e.g. ``author description``).
 
     Valid fields are most regular revision fields and some special fields.
 
     Regular revision fields are ``description``, ``author``, ``branch``,
     ``date``, ``files``, ``phase``, ``parents``, ``substate``, ``user``
     and ``diff``.
     Note that ``author`` and ``user`` are synonyms. ``diff`` refers to the
     contents of the revision. Two revisions matching their ``diff`` will
     also match their ``files``.
 
     Special fields are ``summary`` and ``metadata``:
     ``summary`` matches the first line of the description.
     ``metadata`` is equivalent to matching ``description user date``
     (i.e. it matches the main metadata fields).
 
     ``metadata`` is the default field which is used when no fields are
     specified. You can match more than one field at a time.
     """
     # i18n: "matching" is a keyword
     l = getargs(x, 1, 2, _("matching takes 1 or 2 arguments"))
 
     revs = getset(repo, baseset(repo.changelog), l[0])
 
     fieldlist = ['metadata']
     if len(l) > 1:
             fieldlist = getstring(l[1],
                 # i18n: "matching" is a keyword
                 _("matching requires a string "
                 "as its second argument")).split()
 
     # Make sure that there are no repeated fields,
     # expand the 'special' 'metadata' field type
     # and check the 'files' whenever we check the 'diff'
     fields = []
     for field in fieldlist:
         if field == 'metadata':
             fields += ['user', 'description', 'date']
         elif field == 'diff':
             # a revision matching the diff must also match the files
             # since matching the diff is very costly, make sure to
             # also match the files first
             fields += ['files', 'diff']
         else:
             if field == 'author':
                 field = 'user'
             fields.append(field)
     fields = set(fields)
     if 'summary' in fields and 'description' in fields:
         # If a revision matches its description it also matches its summary
         fields.discard('summary')
 
     # We may want to match more than one field
     # Not all fields take the same amount of time to be matched
     # Sort the selected fields in order of increasing matching cost
     fieldorder = ['phase', 'parents', 'user', 'date', 'branch', 'summary',
         'files', 'description', 'substate', 'diff']
     def fieldkeyfunc(f):
         try:
             return fieldorder.index(f)
         except ValueError:
             # assume an unknown field is very costly
             return len(fieldorder)
     fields = list(fields)
     fields.sort(key=fieldkeyfunc)
 
     # Each field will be matched with its own "getfield" function
     # which will be added to the getfieldfuncs array of functions
     getfieldfuncs = []
     _funcs = {
         'user': lambda r: repo[r].user(),
         'branch': lambda r: repo[r].branch(),
         'date': lambda r: repo[r].date(),
         'description': lambda r: repo[r].description(),
         'files': lambda r: repo[r].files(),
         'parents': lambda r: repo[r].parents(),
         'phase': lambda r: repo[r].phase(),
         'substate': lambda r: repo[r].substate,
         'summary': lambda r: repo[r].description().splitlines()[0],
         'diff': lambda r: list(repo[r].diff(git=True),)
     }
     for info in fields:
         getfield = _funcs.get(info, None)
         if getfield is None:
             raise error.ParseError(
                 # i18n: "matching" is a keyword
                 _("unexpected field name passed to matching: %s") % info)
         getfieldfuncs.append(getfield)
     # convert the getfield array of functions into a "getinfo" function
     # which returns an array of field values (or a single value if there
     # is only one field to match)
     getinfo = lambda r: [f(r) for f in getfieldfuncs]
 
     def matches(x):
         for rev in revs:
             target = getinfo(rev)
             match = True
             for n, f in enumerate(getfieldfuncs):
                 if target[n] != f(x):
                     match = False
             if match:
                 return True
         return False
 
     return subset.filter(matches)
 
 def reverse(repo, subset, x):
     """``reverse(set)``
     Reverse order of set.
     """
     l = getset(repo, subset, x)
     l.reverse()
     return l
 
 def roots(repo, subset, x):
     """``roots(set)``
     Changesets in set with no parent changeset in set.
     """
     s = getset(repo, spanset(repo), x).set()
     subset = baseset([r for r in s if r in subset.set()])
     cs = _children(repo, subset, s)
     return subset - cs
 
 def secret(repo, subset, x):
     """``secret()``
     Changeset in secret phase."""
     # i18n: "secret" is a keyword
     getargs(x, 0, 0, _("secret takes no arguments"))
     pc = repo._phasecache
     return subset.filter(lambda x: pc.phase(repo, x) == phases.secret)
 
 def sort(repo, subset, x):
     """``sort(set[, [-]key...])``
     Sort set by keys. The default sort order is ascending, specify a key
     as ``-key`` to sort in descending order.
 
     The keys can be:
 
     - ``rev`` for the revision number,
     - ``branch`` for the branch name,
     - ``desc`` for the commit message (description),
     - ``user`` for user name (``author`` can be used as an alias),
     - ``date`` for the commit date
     """
     # i18n: "sort" is a keyword
     l = getargs(x, 1, 2, _("sort requires one or two arguments"))
     keys = "rev"
     if len(l) == 2:
         # i18n: "sort" is a keyword
         keys = getstring(l[1], _("sort spec must be a string"))
 
     s = l[0]
     keys = keys.split()
     l = []
     def invert(s):
         return "".join(chr(255 - ord(c)) for c in s)
     revs = getset(repo, subset, s)
     if keys == ["rev"]:
         revs.sort()
         return revs
     elif keys == ["-rev"]:
         revs.sort(reverse=True)
         return revs
     for r in revs:
         c = repo[r]
         e = []
         for k in keys:
             if k == 'rev':
                 e.append(r)
             elif k == '-rev':
                 e.append(-r)
             elif k == 'branch':
                 e.append(c.branch())
             elif k == '-branch':
                 e.append(invert(c.branch()))
             elif k == 'desc':
                 e.append(c.description())
             elif k == '-desc':
                 e.append(invert(c.description()))
             elif k in 'user author':
                 e.append(c.user())
             elif k in '-user -author':
                 e.append(invert(c.user()))
             elif k == 'date':
                 e.append(c.date()[0])
             elif k == '-date':
                 e.append(-c.date()[0])
             else:
                 raise error.ParseError(_("unknown sort key %r") % k)
         e.append(r)
         l.append(e)
     l.sort()
     return baseset([e[-1] for e in l])
 
 def _stringmatcher(pattern):
     """
     accepts a string, possibly starting with 're:' or 'literal:' prefix.
     returns the matcher name, pattern, and matcher function.
     missing or unknown prefixes are treated as literal matches.
 
     helper for tests:
     >>> def test(pattern, *tests):
     ...     kind, pattern, matcher = _stringmatcher(pattern)
     ...     return (kind, pattern, [bool(matcher(t)) for t in tests])
 
     exact matching (no prefix):
     >>> test('abcdefg', 'abc', 'def', 'abcdefg')
     ('literal', 'abcdefg', [False, False, True])
 
     regex matching ('re:' prefix)
     >>> test('re:a.+b', 'nomatch', 'fooadef', 'fooadefbar')
     ('re', 'a.+b', [False, False, True])
 
     force exact matches ('literal:' prefix)
     >>> test('literal:re:foobar', 'foobar', 're:foobar')
     ('literal', 're:foobar', [False, True])
 
     unknown prefixes are ignored and treated as literals
     >>> test('foo:bar', 'foo', 'bar', 'foo:bar')
     ('literal', 'foo:bar', [False, False, True])
     """
     if pattern.startswith('re:'):
         pattern = pattern[3:]
         try:
             regex = re.compile(pattern)
         except re.error, e:
             raise error.ParseError(_('invalid regular expression: %s')
                                    % e)
         return 're', pattern, regex.search
     elif pattern.startswith('literal:'):
         pattern = pattern[8:]
     return 'literal', pattern, pattern.__eq__
 
 def _substringmatcher(pattern):
     kind, pattern, matcher = _stringmatcher(pattern)
     if kind == 'literal':
         matcher = lambda s: pattern in s
     return kind, pattern, matcher
 
 def tag(repo, subset, x):
     """``tag([name])``
     The specified tag by name, or all tagged revisions if no name is given.
 
     If `name` starts with `re:`, the remainder of the name is treated as
     a regular expression. To match a tag that actually starts with `re:`,
     use the prefix `literal:`.
     """
     # i18n: "tag" is a keyword
     args = getargs(x, 0, 1, _("tag takes one or no arguments"))
     cl = repo.changelog
     if args:
         pattern = getstring(args[0],
                             # i18n: "tag" is a keyword
                             _('the argument to tag must be a string'))
         kind, pattern, matcher = _stringmatcher(pattern)
         if kind == 'literal':
             # avoid resolving all tags
             tn = repo._tagscache.tags.get(pattern, None)
             if tn is None:
                 raise util.Abort(_("tag '%s' does not exist") % pattern)
             s = set([repo[tn].rev()])
         else:
             s = set([cl.rev(n) for t, n in repo.tagslist() if matcher(t)])
     else:
         s = set([cl.rev(n) for t, n in repo.tagslist() if t != 'tip'])
     return subset & s
 
 def tagged(repo, subset, x):
     return tag(repo, subset, x)
 
 def unstable(repo, subset, x):
     """``unstable()``
     Non-obsolete changesets with obsolete ancestors.
     """
     # i18n: "unstable" is a keyword
     getargs(x, 0, 0, _("unstable takes no arguments"))
     unstables = obsmod.getrevs(repo, 'unstable')
     return subset & unstables
 
 
 def user(repo, subset, x):
     """``user(string)``
     User name contains string. The match is case-insensitive.
 
     If `string` starts with `re:`, the remainder of the string is treated as
     a regular expression. To match a user that actually contains `re:`, use
     the prefix `literal:`.
     """
     return author(repo, subset, x)
 
 # for internal use
 def _list(repo, subset, x):
     s = getstring(x, "internal error")
     if not s:
         return baseset([])
     ls = [repo[r].rev() for r in s.split('\0')]
     s = subset.set()
     return baseset([r for r in ls if r in s])
 
 # for internal use
 def _intlist(repo, subset, x):
     s = getstring(x, "internal error")
     if not s:
         return baseset([])
     ls = [int(r) for r in s.split('\0')]
     s = subset.set()
     return baseset([r for r in ls if r in s])
 
 # for internal use
 def _hexlist(repo, subset, x):
     s = getstring(x, "internal error")
     if not s:
         return baseset([])
     cl = repo.changelog
     ls = [cl.rev(node.bin(r)) for r in s.split('\0')]
     s = subset.set()
     return baseset([r for r in ls if r in s])
 
 symbols = {
     "adds": adds,
     "all": getall,
     "ancestor": ancestor,
     "ancestors": ancestors,
     "_firstancestors": _firstancestors,
     "author": author,
     "only": only,
     "bisect": bisect,
     "bisected": bisected,
     "bookmark": bookmark,
     "branch": branch,
     "branchpoint": branchpoint,
     "bumped": bumped,
     "bundle": bundle,
     "children": children,
     "closed": closed,
     "contains": contains,
     "converted": converted,
     "date": date,
     "desc": desc,
     "descendants": descendants,
     "_firstdescendants": _firstdescendants,
     "destination": destination,
     "divergent": divergent,
     "draft": draft,
     "extinct": extinct,
     "extra": extra,
     "file": hasfile,
     "filelog": filelog,
     "first": first,
     "follow": follow,
     "_followfirst": _followfirst,
     "grep": grep,
     "head": head,
     "heads": heads,
     "hidden": hidden,
     "id": node_,
     "keyword": keyword,
     "last": last,
     "limit": limit,
     "_matchfiles": _matchfiles,
     "max": maxrev,
     "merge": merge,
     "min": minrev,
     "modifies": modifies,
     "obsolete": obsolete,
     "origin": origin,
     "outgoing": outgoing,
     "p1": p1,
     "p2": p2,
     "parents": parents,
     "present": present,
     "public": public,
     "remote": remote,
     "removes": removes,
     "rev": rev,
     "reverse": reverse,
     "roots": roots,
     "sort": sort,
     "secret": secret,
     "matching": matching,
     "tag": tag,
     "tagged": tagged,
     "user": user,
     "unstable": unstable,
     "_list": _list,
     "_intlist": _intlist,
     "_hexlist": _hexlist,
 }
 
 # symbols which can't be used for a DoS attack for any given input
 # (e.g. those which accept regexes as plain strings shouldn't be included)
 # functions that just return a lot of changesets (like all) don't count here
 safesymbols = set([
     "adds",
     "all",
     "ancestor",
     "ancestors",
     "_firstancestors",
     "author",
     "bisect",
     "bisected",
     "bookmark",
     "branch",
     "branchpoint",
     "bumped",
     "bundle",
     "children",
     "closed",
     "converted",
     "date",
     "desc",
     "descendants",
     "_firstdescendants",
     "destination",
     "divergent",
     "draft",
     "extinct",
     "extra",
     "file",
     "filelog",
     "first",
     "follow",
     "_followfirst",
     "head",
     "heads",
     "hidden",
     "id",
     "keyword",
     "last",
     "limit",
     "_matchfiles",
     "max",
     "merge",
     "min",
     "modifies",
     "obsolete",
     "origin",
     "outgoing",
     "p1",
     "p2",
     "parents",
     "present",
     "public",
     "remote",
     "removes",
     "rev",
     "reverse",
     "roots",
     "sort",
     "secret",
     "matching",
     "tag",
     "tagged",
     "user",
     "unstable",
     "_list",
     "_intlist",
     "_hexlist",
 ])
 
 methods = {
     "range": rangeset,
     "dagrange": dagrange,
     "string": stringset,
     "symbol": symbolset,
     "and": andset,
     "or": orset,
     "not": notset,
     "list": listset,
     "func": func,
     "ancestor": ancestorspec,
     "parent": parentspec,
     "parentpost": p1,
 }
 
 def optimize(x, small):
     if x is None:
         return 0, x
 
     smallbonus = 1
     if small:
         smallbonus = .5
 
     op = x[0]
     if op == 'minus':
         return optimize(('and', x[1], ('not', x[2])), small)
     elif op == 'dagrangepre':
         return optimize(('func', ('symbol', 'ancestors'), x[1]), small)
     elif op == 'dagrangepost':
         return optimize(('func', ('symbol', 'descendants'), x[1]), small)
     elif op == 'rangepre':
         return optimize(('range', ('string', '0'), x[1]), small)
     elif op == 'rangepost':
         return optimize(('range', x[1], ('string', 'tip')), small)
     elif op == 'negate':
         return optimize(('string',
                          '-' + getstring(x[1], _("can't negate that"))), small)
     elif op in 'string symbol negate':
         return smallbonus, x # single revisions are small
     elif op == 'and':
         wa, ta = optimize(x[1], True)
         wb, tb = optimize(x[2], True)
 
         # (::x and not ::y)/(not ::y and ::x) have a fast path
         def isonly(revs, bases):
             return (
                 revs[0] == 'func'
                 and getstring(revs[1], _('not a symbol')) == 'ancestors'
                 and bases[0] == 'not'
                 and bases[1][0] == 'func'
                 and getstring(bases[1][1], _('not a symbol')) == 'ancestors')
 
         w = min(wa, wb)
         if isonly(ta, tb):
             return w, ('func', ('symbol', 'only'), ('list', ta[2], tb[1][2]))
         if isonly(tb, ta):
             return w, ('func', ('symbol', 'only'), ('list', tb[2], ta[1][2]))
 
         if wa > wb:
             return w, (op, tb, ta)
         return w, (op, ta, tb)
     elif op == 'or':
         wa, ta = optimize(x[1], False)
         wb, tb = optimize(x[2], False)
         if wb < wa:
             wb, wa = wa, wb
         return max(wa, wb), (op, ta, tb)
     elif op == 'not':
         o = optimize(x[1], not small)
         return o[0], (op, o[1])
     elif op == 'parentpost':
         o = optimize(x[1], small)
         return o[0], (op, o[1])
     elif op == 'group':
         return optimize(x[1], small)
     elif op in 'dagrange range list parent ancestorspec':
         if op == 'parent':
             # x^:y means (x^) : y, not x ^ (:y)
             post = ('parentpost', x[1])
             if x[2][0] == 'dagrangepre':
                 return optimize(('dagrange', post, x[2][1]), small)
             elif x[2][0] == 'rangepre':
                 return optimize(('range', post, x[2][1]), small)
 
         wa, ta = optimize(x[1], small)
         wb, tb = optimize(x[2], small)
         return wa + wb, (op, ta, tb)
     elif op == 'func':
         f = getstring(x[1], _("not a symbol"))
         wa, ta = optimize(x[2], small)
         if f in ("author branch closed date desc file grep keyword "
                  "outgoing user"):
             w = 10 # slow
         elif f in "modifies adds removes":
             w = 30 # slower
         elif f == "contains":
             w = 100 # very slow
         elif f == "ancestor":
             w = 1 * smallbonus
         elif f in "reverse limit first _intlist":
             w = 0
         elif f in "sort":
             w = 10 # assume most sorts look at changelog
         else:
             w = 1
         return w + wa, (op, x[1], ta)
     return 1, x
 
 _aliasarg = ('func', ('symbol', '_aliasarg'))
 def _getaliasarg(tree):
     """If tree matches ('func', ('symbol', '_aliasarg'), ('string', X))
     return X, None otherwise.
     """
     if (len(tree) == 3 and tree[:2] == _aliasarg
         and tree[2][0] == 'string'):
         return tree[2][1]
     return None
 
 def _checkaliasarg(tree, known=None):
     """Check tree contains no _aliasarg construct or only ones which
     value is in known. Used to avoid alias placeholders injection.
     """
     if isinstance(tree, tuple):
         arg = _getaliasarg(tree)
         if arg is not None and (not known or arg not in known):
             raise error.ParseError(_("not a function: %s") % '_aliasarg')
         for t in tree:
             _checkaliasarg(t, known)
 
 class revsetalias(object):
     funcre = re.compile('^([^(]+)\(([^)]+)\)$')
     args = None
 
     def __init__(self, name, value):
         '''Aliases like:
 
         h = heads(default)
         b($1) = ancestors($1) - ancestors(default)
         '''
         m = self.funcre.search(name)
         if m:
             self.name = m.group(1)
             self.tree = ('func', ('symbol', m.group(1)))
             self.args = [x.strip() for x in m.group(2).split(',')]
             for arg in self.args:
                 # _aliasarg() is an unknown symbol only used separate
                 # alias argument placeholders from regular strings.
                 value = value.replace(arg, '_aliasarg(%r)' % (arg,))
         else:
             self.name = name
             self.tree = ('symbol', name)
 
         self.replacement, pos = parse(value)
         if pos != len(value):
             raise error.ParseError(_('invalid token'), pos)
         # Check for placeholder injection
         _checkaliasarg(self.replacement, self.args)
 
 def _getalias(aliases, tree):
     """If tree looks like an unexpanded alias, return it. Return None
     otherwise.
     """
     if isinstance(tree, tuple) and tree:
         if tree[0] == 'symbol' and len(tree) == 2:
             name = tree[1]
             alias = aliases.get(name)
             if alias and alias.args is None and alias.tree == tree:
                 return alias
         if tree[0] == 'func' and len(tree) > 1:
             if tree[1][0] == 'symbol' and len(tree[1]) == 2:
                 name = tree[1][1]
                 alias = aliases.get(name)
                 if alias and alias.args is not None and alias.tree == tree[:2]:
                     return alias
     return None
 
 def _expandargs(tree, args):
     """Replace _aliasarg instances with the substitution value of the
     same name in args, recursively.
     """
     if not tree or not isinstance(tree, tuple):
         return tree
     arg = _getaliasarg(tree)
     if arg is not None:
         return args[arg]
     return tuple(_expandargs(t, args) for t in tree)
 
 def _expandaliases(aliases, tree, expanding, cache):
     """Expand aliases in tree, recursively.
 
     'aliases' is a dictionary mapping user defined aliases to
     revsetalias objects.
     """
     if not isinstance(tree, tuple):
         # Do not expand raw strings
         return tree
     alias = _getalias(aliases, tree)
     if alias is not None:
         if alias in expanding:
             raise error.ParseError(_('infinite expansion of revset alias "%s" '
                                      'detected') % alias.name)
         expanding.append(alias)
         if alias.name not in cache:
             cache[alias.name] = _expandaliases(aliases, alias.replacement,
                                                expanding, cache)
         result = cache[alias.name]
         expanding.pop()
         if alias.args is not None:
             l = getlist(tree[2])
             if len(l) != len(alias.args):
                 raise error.ParseError(
                     _('invalid number of arguments: %s') % len(l))
             l = [_expandaliases(aliases, a, [], cache) for a in l]
             result = _expandargs(result, dict(zip(alias.args, l)))
     else:
         result = tuple(_expandaliases(aliases, t, expanding, cache)
                        for t in tree)
     return result
 
 def findaliases(ui, tree):
     _checkaliasarg(tree)
     aliases = {}
     for k, v in ui.configitems('revsetalias'):
         alias = revsetalias(k, v)
         aliases[alias.name] = alias
     return _expandaliases(aliases, tree, [], {})
 
 def parse(spec, lookup=None):
     p = parser.parser(tokenize, elements)
     return p.parse(spec, lookup=lookup)
 
 def match(ui, spec, repo=None):
     if not spec:
         raise error.ParseError(_("empty query"))
     lookup = None
     if repo:
         lookup = repo.__contains__
     tree, pos = parse(spec, lookup)
     if (pos != len(spec)):
         raise error.ParseError(_("invalid token"), pos)
     if ui:
         tree = findaliases(ui, tree)
     weight, tree = optimize(tree, True)
     def mfunc(repo, subset):
         if util.safehasattr(subset, 'set'):
             result = getset(repo, subset, tree)
         else:
             result = getset(repo, baseset(subset), tree)
         return result
     return mfunc
 
 def formatspec(expr, *args):
     '''
     This is a convenience function for using revsets internally, and
     escapes arguments appropriately. Aliases are intentionally ignored
     so that intended expression behavior isn't accidentally subverted.
 
     Supported arguments:
 
     %r = revset expression, parenthesized
     %d = int(arg), no quoting
     %s = string(arg), escaped and single-quoted
     %b = arg.branch(), escaped and single-quoted
     %n = hex(arg), single-quoted
     %% = a literal '%'
 
     Prefixing the type with 'l' specifies a parenthesized list of that type.
 
     >>> formatspec('%r:: and %lr', '10 or 11', ("this()", "that()"))
     '(10 or 11):: and ((this()) or (that()))'
     >>> formatspec('%d:: and not %d::', 10, 20)
     '10:: and not 20::'
     >>> formatspec('%ld or %ld', [], [1])
     "_list('') or 1"
     >>> formatspec('keyword(%s)', 'foo\\xe9')
     "keyword('foo\\\\xe9')"
     >>> b = lambda: 'default'
     >>> b.branch = b
     >>> formatspec('branch(%b)', b)
     "branch('default')"
     >>> formatspec('root(%ls)', ['a', 'b', 'c', 'd'])
     "root(_list('a\\x00b\\x00c\\x00d'))"
     '''
 
     def quote(s):
         return repr(str(s))
 
     def argtype(c, arg):
         if c == 'd':
             return str(int(arg))
         elif c == 's':
             return quote(arg)
         elif c == 'r':
             parse(arg) # make sure syntax errors are confined
             return '(%s)' % arg
         elif c == 'n':
             return quote(node.hex(arg))
         elif c == 'b':
             return quote(arg.branch())
 
     def listexp(s, t):
         l = len(s)
         if l == 0:
             return "_list('')"
         elif l == 1:
             return argtype(t, s[0])
         elif t == 'd':
             return "_intlist('%s')" % "\0".join(str(int(a)) for a in s)
         elif t == 's':
             return "_list('%s')" % "\0".join(s)
         elif t == 'n':
             return "_hexlist('%s')" % "\0".join(node.hex(a) for a in s)
         elif t == 'b':
             return "_list('%s')" % "\0".join(a.branch() for a in s)
 
         m = l // 2
         return '(%s or %s)' % (listexp(s[:m], t), listexp(s[m:], t))
 
     ret = ''
     pos = 0
     arg = 0
     while pos < len(expr):
         c = expr[pos]
         if c == '%':
             pos += 1
             d = expr[pos]
             if d == '%':
                 ret += d
             elif d in 'dsnbr':
                 ret += argtype(d, args[arg])
                 arg += 1
             elif d == 'l':
                 # a list of some type
                 pos += 1
                 d = expr[pos]
                 ret += listexp(list(args[arg]), d)
                 arg += 1
             else:
                 raise util.Abort('unexpected revspec format character %s' % d)
         else:
             ret += c
         pos += 1
 
     return ret
 
 def prettyformat(tree):
     def _prettyformat(tree, level, lines):
         if not isinstance(tree, tuple) or tree[0] in ('string', 'symbol'):
             lines.append((level, str(tree)))
         else:
             lines.append((level, '(%s' % tree[0]))
             for s in tree[1:]:
                 _prettyformat(s, level + 1, lines)
             lines[-1:] = [(lines[-1][0], lines[-1][1] + ')')]
 
     lines = []
     _prettyformat(tree, 0, lines)
     output = '\n'.join(('  '*l + s) for l, s in lines)
     return output
 
 def depth(tree):
     if isinstance(tree, tuple):
         return max(map(depth, tree)) + 1
     else:
         return 0
 
 def funcsused(tree):
     if not isinstance(tree, tuple) or tree[0] in ('string', 'symbol'):
         return set()
     else:
         funcs = set()
         for s in tree[1:]:
             funcs |= funcsused(s)
         if tree[0] == 'func':
             funcs.add(tree[1][1])
         return funcs
 
 class abstractsmartset(object):
 
     def __nonzero__(self):
         """True if the smartset is not empty"""
         raise NotImplementedError()
 
     def __contains__(self, rev):
         """provide fast membership testing"""
         raise NotImplementedError()
 
     def __set__(self):
         """Returns a set or a smartset containing all the elements.
 
         The returned structure should be the fastest option for membership
         testing.
 
         This is part of the mandatory API for smartset."""
         raise NotImplementedError()
 
     def __iter__(self):
         """iterate the set in the order it is supposed to be iterated"""
         raise NotImplementedError()
 
     # Attributes containing a function to perform a fast iteration in a given
     # direction. A smartset can have none, one, or both defined.
     #
     # Default value is None instead of a function returning None to avoid
     # initializing an iterator just for testing if a fast method exists.
     fastasc = None
     fastdesc = None
 
     def isascending(self):
         """True if the set will iterate in ascending order"""
         raise NotImplementedError()
 
     def ascending(self):
         """Sorts the set in ascending order (in place).
 
         This is part of the mandatory API for smartset."""
         self.sort()
 
     def isdescending(self):
         """True if the set will iterate in descending order"""
         raise NotImplementedError()
 
     def descending(self):
         """Sorts the set in descending order (in place).
 
         This is part of the mandatory API for smartset."""
         self.sort(reverse=True)
 
     def min(self):
         """return the minimum element in the set"""
         if self.fastasc is not None:
             for r in self.fastasc():
                 return r
             raise ValueError('arg is an empty sequence')
         return min(self)
 
     def max(self):
         """return the maximum element in the set"""
         if self.fastdesc is not None:
             for r in self.fastdesc():
                 return r
             raise ValueError('arg is an empty sequence')
         return max(self)
 
     def reverse(self):
         """reverse the expected iteration order"""
         raise NotImplementedError()
 
     def sort(self, reverse=True):
         """get the set to iterate in an ascending or descending order"""
         raise NotImplementedError()
 
     def __and__(self, other):
         """Returns a new object with the intersection of the two collections.
 
         This is part of the mandatory API for smartset."""
         return self.filter(other.__contains__)
 
     def __add__(self, other):
         """Returns a new object with the union of the two collections.
 
         This is part of the mandatory API for smartset."""
         kwargs = {}
         if self.isascending() and other.isascending():
             kwargs['ascending'] = True
         if self.isdescending() and other.isdescending():
             kwargs['ascending'] = False
         return _addset(self, other, **kwargs)
 
     def __sub__(self, other):
         """Returns a new object with the substraction of the two collections.
 
         This is part of the mandatory API for smartset."""
         c = other.__contains__
         return self.filter(lambda r: not c(r))
 
     def filter(self, condition):
         """Returns this smartset filtered by condition as a new smartset.
 
         `condition` is a callable which takes a revision number and returns a
         boolean.
 
         This is part of the mandatory API for smartset."""
         kwargs = {}
         if self.isascending():
             kwargs['ascending'] = True
         elif self.isdescending():
             kwargs['ascending'] = False
         return filteredset(self, condition, **kwargs)
 
 class baseset(list, abstractsmartset):
     """Basic data structure that represents a revset and contains the basic
     operation that it should be able to perform.
 
     Every method in this class should be implemented by any smartset class.
     """
     def __init__(self, data=()):
         super(baseset, self).__init__(data)
         self._set = None
 
     def set(self):
         """Returns a set or a smartset containing all the elements.
 
         The returned structure should be the fastest option for membership
         testing.
 
         This is part of the mandatory API for smartset."""
         if not self._set:
             self._set = set(self)
         return self._set
 
     @util.propertycache
     def __contains__(self):
         return self.set().__contains__
 
     def __nonzero__(self):
         return bool(len(self))
 
     def __sub__(self, other):
         """Returns a new object with the substraction of the two collections.
 
         This is part of the mandatory API for smartset."""
         # If we are operating on 2 baseset, do the computation now since all
         # data is available. The alternative is to involve a filteredset, which
         # may be slow.
         if isinstance(other, baseset):
             other = other.set()
             return baseset([x for x in self if x not in other])
 
         return self.filter(lambda x: x not in other)
 
     def __and__(self, other):
         """Returns a new object with the intersection of the two collections.
 
         This is part of the mandatory API for smartset."""
         return baseset([y for y in self if y in other])
 
     def __add__(self, other):
         """Returns a new object with the union of the two collections.
 
         This is part of the mandatory API for smartset."""
         s = self.set()
         l = [r for r in other if r not in s]
         return baseset(list(self) + l)
 
     def isascending(self):
         """Returns True if the collection is ascending order, False if not.
 
         This is part of the mandatory API for smartset."""
         return False
 
     def isdescending(self):
         """Returns True if the collection is descending order, False if not.
 
         This is part of the mandatory API for smartset."""
         return False
 
 class filteredset(abstractsmartset):
     """Duck type for baseset class which iterates lazily over the revisions in
     the subset and contains a function which tests for membership in the
     revset
     """
     def __init__(self, subset, condition=lambda x: True, ascending=None):
         """
         condition: a function that decide whether a revision in the subset
                    belongs to the revset or not.
         """
         self._subset = subset
         self._condition = condition
         self._cache = {}
         if ascending is not None:
             ascending = bool(ascending)
         self._ascending = ascending
 
     def __contains__(self, x):
         c = self._cache
         if x not in c:
             v = c[x] = x in self._subset and self._condition(x)
             return v
         return c[x]
 
     def __iter__(self):
         return self._iterfilter(self._subset)
 
     def _iterfilter(self, it):
         cond = self._condition
         for x in it:
             if cond(x):
                 yield x
 
     @property
     def fastasc(self):
         it = self._subset.fastasc
         if it is None:
             return None
         return lambda: self._iterfilter(it())
 
     @property
     def fastdesc(self):
         it = self._subset.fastdesc
         if it is None:
             return None
         return lambda: self._iterfilter(it())
 
     def __nonzero__(self):
         for r in self:
             return True
         return False
 
     def __len__(self):
         # Basic implementation to be changed in future patches.
         l = baseset([r for r in self])
         return len(l)
 
     def __getitem__(self, x):
         # Basic implementation to be changed in future patches.
         l = baseset([r for r in self])
         return l[x]
 
     def sort(self, reverse=False):
         if self._ascending is None:
             if not util.safehasattr(self._subset, 'sort'):
                 self._subset = baseset(self._subset)
             self._subset.sort(reverse=reverse)
             self._ascending = not reverse
         elif bool(reverse) == self._ascending:
             self.reverse()
 
     def reverse(self):
         self._subset.reverse()
         if self._ascending is not None:
             self._ascending = not self._ascending
 
     def set(self):
         return set([r for r in self])
 
     def isascending(self):
         return self._ascending is not None and self._ascending
 
     def isdescending(self):
         return self._ascending is not None and not self._ascending
 
 class _addset(abstractsmartset):
     """Represent the addition of two sets
 
     Wrapper structure for lazily adding two structures without losing much
     performance on the __contains__ method
 
     If the ascending attribute is set, that means the two structures are
     ordered in either an ascending or descending way. Therefore, we can add
     them maintaining the order by iterating over both at the same time
 
     This class does not duck-type baseset and it's only supposed to be used
     internally
     """
     def __init__(self, revs1, revs2, ascending=None):
         self._r1 = revs1
         self._r2 = revs2
         self._iter = None
         self._ascending = ascending
         self._genlist = None
 
     def __len__(self):
         return len(self._list)
 
     def __nonzero__(self):
         return bool(self._r1 or self._r2)
 
     @util.propertycache
     def _list(self):
         if not self._genlist:
             self._genlist = baseset(self._iterator())
         return self._genlist
 
     def _iterator(self):
         """Iterate over both collections without repeating elements
 
         If the ascending attribute is not set, iterate over the first one and
         then over the second one checking for membership on the first one so we
         dont yield any duplicates.
 
         If the ascending attribute is set, iterate over both collections at the
         same time, yielding only one value at a time in the given order.
         """
         if not self._iter:
             if self._ascending is None:
                 def gen():
                     for r in self._r1:
                         yield r
                     s = self._r1.set()
                     for r in self._r2:
                         if r not in s:
                             yield r
                 gen = gen()
             else:
                 iter1 = iter(self._r1)
                 iter2 = iter(self._r2)
                 gen = self._iterordered(self._ascending, iter1, iter2)
             self._iter = _generatorset(gen)
         return self._iter
 
     def __iter__(self):
         if self._genlist:
             return iter(self._genlist)
         return iter(self._iterator())
 
     @property
     def fastasc(self):
         iter1 = self._r1.fastasc
         iter2 = self._r2.fastasc
         if None in (iter1, iter2):
             return None
         return lambda: self._iterordered(True, iter1(), iter2())
 
     @property
     def fastdesc(self):
         iter1 = self._r1.fastdesc
         iter2 = self._r2.fastdesc
         if None in (iter1, iter2):
             return None
         return lambda: self._iterordered(False, iter1(), iter2())
 
     def _iterordered(self, ascending, iter1, iter2):
         """produce an ordered iteration from two iterators with the same order
 
         The ascending is used to indicated the iteration direction.
         """
         choice = max
         if ascending:
             choice = min
 
         val1 = None
         val2 = None
 
         choice = max
-        if self._ascending:
+        if ascending:
             choice = min
         try:
             # Consume both iterators in an ordered way until one is
             # empty
             while True:
                 if val1 is None:
                     val1 = iter1.next()
                 if val2 is None:
                     val2 = iter2.next()
                 next = choice(val1, val2)
                 yield next
                 if val1 == next:
                     val1 = None
                 if val2 == next:
                     val2 = None
         except StopIteration:
             # Flush any remaining values and consume the other one
             it = iter2
             if val1 is not None:
                 yield val1
                 it = iter1
             elif val2 is not None:
                 # might have been equality and both are empty
                 yield val2
             for val in it:
                 yield val
 
     def __contains__(self, x):
         return x in self._r1 or x in self._r2
 
     def set(self):
         return self
 
     def sort(self, reverse=False):
         """Sort the added set
 
         For this we use the cached list with all the generated values and if we
         know they are ascending or descending we can sort them in a smart way.
         """
         if self._ascending is None:
             self._list.sort(reverse=reverse)
             self._ascending = not reverse
         else:
             if bool(self._ascending) == bool(reverse):
                 self.reverse()
 
     def isascending(self):
         return self._ascending is not None and self._ascending
 
     def isdescending(self):
         return self._ascending is not None and not self._ascending
 
     def reverse(self):
         self._list.reverse()
         if self._ascending is not None:
             self._ascending = not self._ascending
 
 class _generatorset(abstractsmartset):
     """Wrap a generator for lazy iteration
 
     Wrapper structure for generators that provides lazy membership and can
     be iterated more than once.
     When asked for membership it generates values until either it finds the
     requested one or has gone through all the elements in the generator
 
     This class does not duck-type baseset and it's only supposed to be used
     internally
     """
     def __init__(self, gen, iterasc=None):
         """
         gen: a generator producing the values for the generatorset.
         """
         self._gen = gen
         self._cache = {}
         self._genlist = baseset([])
         self._finished = False
         if iterasc is not None:
             if iterasc:
                 self.fastasc = self.__iter__
                 self.__contains__ = self._asccontains
             else:
                 self.fastdesc = self.__iter__
                 self.__contains__ = self._desccontains
 
     def __nonzero__(self):
         for r in self:
             return True
         return False
 
     def __contains__(self, x):
         if x in self._cache:
             return self._cache[x]
 
         # Use new values only, as existing values would be cached.
         for l in self._consumegen():
             if l == x:
                 return True
 
         self._cache[x] = False
         return False
 
     def _asccontains(self, x):
         """version of contains optimised for ascending generator"""
         if x in self._cache:
             return self._cache[x]
 
         # Use new values only, as existing values would be cached.
         for l in self._consumegen():
             if l == x:
                 return True
             if l > x:
                 break
 
         self._cache[x] = False
         return False
 
     def _desccontains(self, x):
         """version of contains optimised for descending generator"""
         if x in self._cache:
             return self._cache[x]
 
         # Use new values only, as existing values would be cached.
         for l in self._consumegen():
             if l == x:
                 return True
             if l < x:
                 break
 
         self._cache[x] = False
         return False
 
     def __iter__(self):
         if self._finished:
             return iter(self._genlist)
 
         # We have to use this complex iteration strategy to allow multiple
         # iterations at the same time. We need to be able to catch revision
         # removed from `consumegen` and added to genlist in another instance.
         #
         # Getting rid of it would provide an about 15% speed up on this
         # iteration.
         genlist = self._genlist
         nextrev = self._consumegen().next
         _len = len # cache global lookup
         def gen():
             i = 0
             while True:
                 if i < _len(genlist):
                     yield genlist[i]
                 else:
                     yield nextrev()
                 i += 1
         return gen()
 
     def _consumegen(self):
         cache = self._cache
         genlist = self._genlist.append
         for item in self._gen:
             cache[item] = True
             genlist(item)
             yield item
         self._finished = True
 
     def set(self):
         return self
 
     def sort(self, reverse=False):
         if not self._finished:
             for i in self:
                 continue
         self._genlist.sort(reverse=reverse)
 
 def spanset(repo, start=None, end=None):
     """factory function to dispatch between fullreposet and actual spanset
 
     Feel free to update all spanset call sites and kill this function at some
     point.
     """
     if start is None and end is None:
         return fullreposet(repo)
     return _spanset(repo, start, end)
 
 
 class _spanset(abstractsmartset):
     """Duck type for baseset class which represents a range of revisions and
     can work lazily and without having all the range in memory
 
     Note that spanset(x, y) behave almost like xrange(x, y) except for two
     notable points:
     - when x < y it will be automatically descending,
     - revision filtered with this repoview will be skipped.
 
     """
     def __init__(self, repo, start=0, end=None):
         """
         start: first revision included the set
                (default to 0)
         end:   first revision excluded (last+1)
                (default to len(repo)
 
         Spanset will be descending if `end` < `start`.
         """
         if end is None:
             end = len(repo)
         self._ascending = start <= end
         if not self._ascending:
             start, end = end + 1, start +1
         self._start = start
         self._end = end
         self._hiddenrevs = repo.changelog.filteredrevs
 
     def sort(self, reverse=False):
         self._ascending = not reverse
 
     def reverse(self):
         self._ascending = not self._ascending
 
     def _iterfilter(self, iterrange):
         s = self._hiddenrevs
         for r in iterrange:
             if r not in s:
                 yield r
 
     def __iter__(self):
         if self._ascending:
             return self.fastasc()
         else:
             return self.fastdesc()
 
     def fastasc(self):
         iterrange = xrange(self._start, self._end)
         if self._hiddenrevs:
             return self._iterfilter(iterrange)
         return iter(iterrange)
 
     def fastdesc(self):
         iterrange = xrange(self._end - 1, self._start - 1, -1)
         if self._hiddenrevs:
             return self._iterfilter(iterrange)
         return iter(iterrange)
 
     def __contains__(self, rev):
         hidden = self._hiddenrevs
         return ((self._start <= rev < self._end)
                 and not (hidden and rev in hidden))
 
     def __nonzero__(self):
         for r in self:
             return True
         return False
 
     def __len__(self):
         if not self._hiddenrevs:
             return abs(self._end - self._start)
         else:
             count = 0
             start = self._start
             end = self._end
             for rev in self._hiddenrevs:
                 if (end < rev <= start) or (start <= rev < end):
                     count += 1
             return abs(self._end - self._start) - count
 
     def __getitem__(self, x):
         # Basic implementation to be changed in future patches.
         l = baseset([r for r in self])
         return l[x]
 
     def set(self):
         return self
 
     def isascending(self):
         return self._start <= self._end
 
     def isdescending(self):
         return self._start >= self._end
 
 class fullreposet(_spanset):
     """a set containing all revisions in the repo
 
     This class exists to host special optimisation.
     """
 
     def __init__(self, repo):
         super(fullreposet, self).__init__(repo)
 
     def __and__(self, other):
         """fullrepo & other -> other
 
         As self contains the whole repo, all of the other set should also be in
         self. Therefor `self & other = other`.
 
         This boldly assumes the other contains valid revs only.
         """
         # other not a smartset, make is so
         if not util.safehasattr(other, 'set'):
             # filter out hidden revision
             # (this boldly assumes all smartset are pure)
             #
             # `other` was used with "&", let's assume this is a set like
             # object.
             other = baseset(other - self._hiddenrevs)
         elif not util.safehasattr(other, 'ascending'):
             # "other" is _generatorset not a real smart set
             # we fallback to the old way (sad kitten)
             return super(fullreposet, self).__and__(other)
 
         # preserve order:
         #
         # this is probably useless and harmful in multiple cases but matches
         # the current behavior.
         if self.isascending():
             other.ascending()
         else:
             other.descending()
         return other
 
 # tell hggettext to extract docstrings from these functions:
 i18nfunctions = symbols.values()

tests/test-tag.t

@@ -1,606 +1,612 b''
   $ hg init test
   $ cd test
 
   $ echo a > a
   $ hg add a
   $ hg commit -m "test"
   $ hg history
   changeset:   0:acb14030fe0a
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     test
   
 
   $ hg tag ' '
   abort: tag names cannot consist entirely of whitespace
   [255]
 
 (this tests also that editor is not invoked, if '--edit' is not
 specified)
 
   $ HGEDITOR=cat hg tag "bleah"
   $ hg history
   changeset:   1:d4f0d2909abc
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Added tag bleah for changeset acb14030fe0a
   
   changeset:   0:acb14030fe0a
   tag:         bleah
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     test
   
 
   $ echo foo >> .hgtags
   $ hg tag "bleah2"
   abort: working copy of .hgtags is changed
   (please commit .hgtags manually)
   [255]
 
   $ hg revert .hgtags
   $ hg tag -r 0 x y z y y z
   abort: tag names must be unique
   [255]
   $ hg tag tap nada dot tip
   abort: the name 'tip' is reserved
   [255]
   $ hg tag .
   abort: the name '.' is reserved
   [255]
   $ hg tag null
   abort: the name 'null' is reserved
   [255]
   $ hg tag "bleah"
   abort: tag 'bleah' already exists (use -f to force)
   [255]
   $ hg tag "blecch" "bleah"
   abort: tag 'bleah' already exists (use -f to force)
   [255]
 
   $ hg tag --remove "blecch"
   abort: tag 'blecch' does not exist
   [255]
   $ hg tag --remove "bleah" "blecch" "blough"
   abort: tag 'blecch' does not exist
   [255]
 
   $ hg tag -r 0 "bleah0"
   $ hg tag -l -r 1 "bleah1"
   $ hg tag gack gawk gorp
   $ hg tag -f gack
   $ hg tag --remove gack gorp
 
   $ hg tag "bleah "
   abort: tag 'bleah' already exists (use -f to force)
   [255]
   $ hg tag " bleah"
   abort: tag 'bleah' already exists (use -f to force)
   [255]
   $ hg tag " bleah"
   abort: tag 'bleah' already exists (use -f to force)
   [255]
   $ hg tag -r 0 "  bleahbleah  "
   $ hg tag -r 0 " bleah bleah "
 
   $ cat .hgtags
   acb14030fe0a21b60322c440ad2d20cf7685a376 bleah
   acb14030fe0a21b60322c440ad2d20cf7685a376 bleah0
   336fccc858a4eb69609a291105009e484a6b6b8d gack
   336fccc858a4eb69609a291105009e484a6b6b8d gawk
   336fccc858a4eb69609a291105009e484a6b6b8d gorp
   336fccc858a4eb69609a291105009e484a6b6b8d gack
   799667b6f2d9b957f73fa644a918c2df22bab58f gack
   799667b6f2d9b957f73fa644a918c2df22bab58f gack
   0000000000000000000000000000000000000000 gack
   336fccc858a4eb69609a291105009e484a6b6b8d gorp
   0000000000000000000000000000000000000000 gorp
   acb14030fe0a21b60322c440ad2d20cf7685a376 bleahbleah
   acb14030fe0a21b60322c440ad2d20cf7685a376 bleah bleah
 
   $ cat .hg/localtags
   d4f0d2909abc9290e2773c08837d70c1794e3f5a bleah1
 
 tagging on a non-head revision
 
   $ hg update 0
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg tag -l localblah
   $ hg tag "foobar"
   abort: not at a branch head (use -f to force)
   [255]
   $ hg tag -f "foobar"
   $ cat .hgtags
   acb14030fe0a21b60322c440ad2d20cf7685a376 foobar
   $ cat .hg/localtags
   d4f0d2909abc9290e2773c08837d70c1794e3f5a bleah1
   acb14030fe0a21b60322c440ad2d20cf7685a376 localblah
 
   $ hg tag -l 'xx
   > newline'
   abort: '\n' cannot be used in a name
   [255]
   $ hg tag -l 'xx:xx'
   abort: ':' cannot be used in a name
   [255]
 
 cloning local tags
 
   $ cd ..
   $ hg -R test log -r0:5
   changeset:   0:acb14030fe0a
   tag:         bleah
   tag:         bleah bleah
   tag:         bleah0
   tag:         bleahbleah
   tag:         foobar
   tag:         localblah
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     test
   
   changeset:   1:d4f0d2909abc
   tag:         bleah1
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Added tag bleah for changeset acb14030fe0a
   
   changeset:   2:336fccc858a4
   tag:         gawk
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Added tag bleah0 for changeset acb14030fe0a
   
   changeset:   3:799667b6f2d9
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Added tag gack, gawk, gorp for changeset 336fccc858a4
   
   changeset:   4:154eeb7c0138
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Added tag gack for changeset 799667b6f2d9
   
   changeset:   5:b4bb47aaff09
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Removed tag gack, gorp
   
   $ hg clone -q -rbleah1 test test1
   $ hg -R test1 parents --style=compact
   1[tip]   d4f0d2909abc   1970-01-01 00:00 +0000   test
     Added tag bleah for changeset acb14030fe0a
   
   $ hg clone -q -r5 test#bleah1 test2
   $ hg -R test2 parents --style=compact
   5[tip]   b4bb47aaff09   1970-01-01 00:00 +0000   test
     Removed tag gack, gorp
   
   $ hg clone -q -U test#bleah1 test3
   $ hg -R test3 parents --style=compact
 
   $ cd test
 
 Issue601: hg tag doesn't do the right thing if .hgtags or localtags
 doesn't end with EOL
 
   $ python << EOF
   > f = file('.hg/localtags'); last = f.readlines()[-1][:-1]; f.close()
   > f = file('.hg/localtags', 'w'); f.write(last); f.close()
   > EOF
   $ cat .hg/localtags; echo
   acb14030fe0a21b60322c440ad2d20cf7685a376 localblah
   $ hg tag -l localnewline
   $ cat .hg/localtags; echo
   acb14030fe0a21b60322c440ad2d20cf7685a376 localblah
   c2899151f4e76890c602a2597a650a72666681bf localnewline
   
 
   $ python << EOF
   > f = file('.hgtags'); last = f.readlines()[-1][:-1]; f.close()
   > f = file('.hgtags', 'w'); f.write(last); f.close()
   > EOF
   $ hg ci -m'broken manual edit of .hgtags'
   $ cat .hgtags; echo
   acb14030fe0a21b60322c440ad2d20cf7685a376 foobar
   $ hg tag newline
   $ cat .hgtags; echo
   acb14030fe0a21b60322c440ad2d20cf7685a376 foobar
   a0eea09de1eeec777b46f2085260a373b2fbc293 newline
   
 
 tag and branch using same name
 
   $ hg branch tag-and-branch-same-name
   marked working directory as branch tag-and-branch-same-name
   (branches are permanent and global, did you want a bookmark?)
   $ hg ci -m"discouraged"
   $ hg tag tag-and-branch-same-name
   warning: tag tag-and-branch-same-name conflicts with existing branch name
 
 test custom commit messages
 
   $ cat > editor.sh << '__EOF__'
   > echo "==== before editing"
   > cat "$1"
   > echo "===="
   > echo "custom tag message" > "$1"
   > echo "second line" >> "$1"
   > __EOF__
 
 at first, test saving last-message.txt
 
 (test that editor is not invoked before transaction starting)
 
   $ cat > .hg/hgrc << '__EOF__'
   > [hooks]
   > # this failure occurs before editor invocation
   > pretag.test-saving-lastmessage = false
   > __EOF__
   $ rm -f .hg/last-message.txt
   $ HGEDITOR="\"sh\" \"`pwd`/editor.sh\"" hg tag custom-tag -e
   abort: pretag.test-saving-lastmessage hook exited with status 1
   [255]
   $ test -f .hg/last-message.txt
   [1]
 
 (test that editor is invoked and commit message is saved into
 "last-message.txt")
 
   $ cat >> .hg/hgrc << '__EOF__'
   > [hooks]
   > pretag.test-saving-lastmessage =
   > # this failure occurs after editor invocation
   > pretxncommit.unexpectedabort = false
   > __EOF__
 
 (this tests also that editor is invoked, if '--edit' is specified,
 regardless of '--message')
 
   $ rm -f .hg/last-message.txt
   $ HGEDITOR="\"sh\" \"`pwd`/editor.sh\"" hg tag custom-tag -e -m "foo bar"
   ==== before editing
   foo bar
   
   
   HG: Enter commit message.  Lines beginning with 'HG:' are removed.
   HG: Leave message empty to abort commit.
   HG: --
   HG: user: test
   HG: branch 'tag-and-branch-same-name'
   HG: changed .hgtags
   ====
   transaction abort!
   rollback completed
   note: commit message saved in .hg/last-message.txt
   abort: pretxncommit.unexpectedabort hook exited with status 1
   [255]
   $ cat .hg/last-message.txt
   custom tag message
   second line
 
   $ cat >> .hg/hgrc << '__EOF__'
   > [hooks]
   > pretxncommit.unexpectedabort =
   > __EOF__
   $ hg status .hgtags
   M .hgtags
   $ hg revert --no-backup -q .hgtags
 
 then, test custom commit message itself
 
   $ HGEDITOR="\"sh\" \"`pwd`/editor.sh\"" hg tag custom-tag -e
   ==== before editing
   Added tag custom-tag for changeset 75a534207be6
   
   
   HG: Enter commit message.  Lines beginning with 'HG:' are removed.
   HG: Leave message empty to abort commit.
   HG: --
   HG: user: test
   HG: branch 'tag-and-branch-same-name'
   HG: changed .hgtags
   ====
   $ hg log -l1 --template "{desc}\n"
   custom tag message
   second line
 
 
 local tag with .hgtags modified
 
   $ hg tag hgtags-modified
   $ hg rollback
   repository tip rolled back to revision 13 (undo commit)
   working directory now based on revision 13
   $ hg st
   M .hgtags
   ? .hgtags.orig
   ? editor.sh
   $ hg tag --local baz
   $ hg revert --no-backup .hgtags
 
 
 tagging when at named-branch-head that's not a topo-head
 
   $ hg up default
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge -t internal:local
   0 files updated, 1 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'merge named branch'
   $ hg up 13
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg tag new-topo-head
 
 tagging on null rev
 
   $ hg up null
   0 files updated, 0 files merged, 2 files removed, 0 files unresolved
   $ hg tag nullrev
   abort: not at a branch head (use -f to force)
   [255]
 
   $ hg init empty
   $ hg tag -R empty nullrev
   abort: cannot tag null revision
   [255]
 
   $ hg tag -R empty -r 00000000000 -f nulltag
   abort: cannot tag null revision
   [255]
 
   $ cd ..
 
 tagging on an uncommitted merge (issue2542)
 
   $ hg init repo-tag-uncommitted-merge
   $ cd repo-tag-uncommitted-merge
   $ echo c1 > f1
   $ hg ci -Am0
   adding f1
   $ echo c2 > f2
   $ hg ci -Am1
   adding f2
   $ hg co -q 0
   $ hg branch b1
   marked working directory as branch b1
   (branches are permanent and global, did you want a bookmark?)
   $ hg ci -m2
   $ hg up default
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge b1
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
 
   $ hg tag t1
   abort: uncommitted merge
   [255]
   $ hg status
   $ hg tag --rev 1 t2
   abort: uncommitted merge
   [255]
   $ hg tag --rev 1 --local t3
   $ hg tags -v
   tip                                2:2a156e8887cc
   t3                                 1:c3adabd1a5f4 local
 
   $ cd ..
 
 commit hook on tag used to be run without write lock - issue3344
 
   $ hg init repo-tag
   $ touch repo-tag/test
   $ hg -R repo-tag commit -A -m "test"
   adding test
   $ hg init repo-tag-target
   $ hg -R repo-tag --config hooks.commit="\"hg\" push \"`pwd`/repo-tag-target\"" tag tag
   pushing to $TESTTMP/repo-tag-target (glob)
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 2 changesets with 2 changes to 2 files
 
 automatically merge resolvable tag conflicts (i.e. tags that differ in rank)
 create two clones with some different tags as well as some common tags
 check that we can merge tags that differ in rank
 
   $ hg init repo-automatic-tag-merge
   $ cd repo-automatic-tag-merge
   $ echo c0 > f0
   $ hg ci -A -m0
   adding f0
   $ hg tag tbase
   $ cd ..
   $ hg clone repo-automatic-tag-merge repo-automatic-tag-merge-clone
   updating to branch default
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cd repo-automatic-tag-merge-clone
   $ echo c1 > f1
   $ hg ci -A -m1
   adding f1
   $ hg tag t1 t2 t3
   $ hg tag --remove t2
   $ hg tag t5
   $ echo c2 > f2
   $ hg ci -A -m2
   adding f2
   $ hg tag -f t3
 
   $ cd ../repo-automatic-tag-merge
   $ echo c3 > f3
   $ hg ci -A -m3
   adding f3
   $ hg tag -f t4 t5 t6
   $ hg tag --remove t5
   $ echo c4 > f4
   $ hg ci -A -m4
   adding f4
   $ hg tag t2
   $ hg tag -f t6
 
   $ cd ../repo-automatic-tag-merge-clone
   $ hg pull
   pulling from $TESTTMP/repo-automatic-tag-merge (glob)
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 6 changesets with 6 changes to 3 files (+1 heads)
   (run 'hg heads' to see heads, 'hg merge' to merge)
   $ hg merge --tool internal:tagmerge
   merging .hgtags
   2 files updated, 1 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg status
   M .hgtags
   M f3
   M f4
   $ hg resolve -l
   R .hgtags
   $ cat .hgtags
   9aa4e1292a27a248f8d07339bed9931d54907be7 t4
   9aa4e1292a27a248f8d07339bed9931d54907be7 t6
   9aa4e1292a27a248f8d07339bed9931d54907be7 t6
   09af2ce14077a94effef208b49a718f4836d4338 t6
   6cee5c8f3e5b4ae1a3996d2f6489c3e08eb5aea7 tbase
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t1
   929bca7b18d067cbf3844c3896319a940059d748 t2
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t2
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t3
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t2
   0000000000000000000000000000000000000000 t2
   875517b4806a848f942811a315a5bce30804ae85 t5
   9aa4e1292a27a248f8d07339bed9931d54907be7 t5
   9aa4e1292a27a248f8d07339bed9931d54907be7 t5
   0000000000000000000000000000000000000000 t5
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t3
   79505d5360b07e3e79d1052e347e73c02b8afa5b t3
 
 check that the merge tried to minimize the diff witht he first merge parent
 
   $ hg diff --git -r 'p1()' .hgtags
   diff --git a/.hgtags b/.hgtags
   --- a/.hgtags
   +++ b/.hgtags
   @@ -1,9 +1,17 @@
   +9aa4e1292a27a248f8d07339bed9931d54907be7 t4
   +9aa4e1292a27a248f8d07339bed9931d54907be7 t6
   +9aa4e1292a27a248f8d07339bed9931d54907be7 t6
   +09af2ce14077a94effef208b49a718f4836d4338 t6
    6cee5c8f3e5b4ae1a3996d2f6489c3e08eb5aea7 tbase
    4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t1
   +929bca7b18d067cbf3844c3896319a940059d748 t2
    4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t2
    4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t3
    4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t2
    0000000000000000000000000000000000000000 t2
    875517b4806a848f942811a315a5bce30804ae85 t5
   +9aa4e1292a27a248f8d07339bed9931d54907be7 t5
   +9aa4e1292a27a248f8d07339bed9931d54907be7 t5
   +0000000000000000000000000000000000000000 t5
    4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t3
    79505d5360b07e3e79d1052e347e73c02b8afa5b t3
 
 detect merge tag conflicts
 
   $ hg update -C -r tip
   3 files updated, 0 files merged, 2 files removed, 0 files unresolved
   $ hg tag t7
   $ hg update -C -r 'first(sort(head()))'
   3 files updated, 0 files merged, 2 files removed, 0 files unresolved
   $ printf "%s %s\n" `hg log -r . --template "{node} t7"` >> .hgtags
   $ hg commit -m "manually add conflicting t7 tag"
   $ hg merge --tool internal:tagmerge
   merging .hgtags
   automatic .hgtags merge failed
   the following 1 tags are in conflict: t7
   automatic tag merging of .hgtags failed! (use 'hg resolve --tool :merge' or another merge tool of your choice)
   2 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
   [1]
   $ hg resolve -l
   U .hgtags
   $ cat .hgtags
   6cee5c8f3e5b4ae1a3996d2f6489c3e08eb5aea7 tbase
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t1
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t2
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t3
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t2
   0000000000000000000000000000000000000000 t2
   875517b4806a848f942811a315a5bce30804ae85 t5
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t3
   79505d5360b07e3e79d1052e347e73c02b8afa5b t3
   ea918d56be86a4afc5a95312e8b6750e1428d9d2 t7
 
   $ cd ..
 
 handle the loss of tags
 
   $ hg clone repo-automatic-tag-merge-clone repo-merge-lost-tags
   updating to branch default
   4 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cd repo-merge-lost-tags
   $ echo c5 > f5
   $ hg ci -A -m5
   adding f5
   $ hg tag -f t7
   $ hg update -r 'p1(t7)'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ printf '' > .hgtags
   $ hg commit -m 'delete all tags'
   created new head
+  $ hg log -r 'max(t7::)'
+  changeset:   17:ffe462b50880
+  user:        test
+  date:        Thu Jan 01 00:00:00 1970 +0000
+  summary:     Added tag t7 for changeset fd3a9e394ce3
+  
   $ hg update -r 'max(t7::)'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge -r tip --tool internal:tagmerge
   merging .hgtags
   0 files updated, 1 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg resolve -l
   R .hgtags
   $ cat .hgtags
   6cee5c8f3e5b4ae1a3996d2f6489c3e08eb5aea7 tbase
   0000000000000000000000000000000000000000 tbase
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t1
   0000000000000000000000000000000000000000 t1
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t2
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t3
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t2
   0000000000000000000000000000000000000000 t2
   875517b4806a848f942811a315a5bce30804ae85 t5
   0000000000000000000000000000000000000000 t5
   4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t3
   79505d5360b07e3e79d1052e347e73c02b8afa5b t3
   0000000000000000000000000000000000000000 t3
   ea918d56be86a4afc5a95312e8b6750e1428d9d2 t7
   0000000000000000000000000000000000000000 t7
   ea918d56be86a4afc5a95312e8b6750e1428d9d2 t7
   fd3a9e394ce3afb354a496323bf68ac1755a30de t7
 
 also check that we minimize the diff with the 1st merge parent
 
   $ hg diff --git -r 'p1()' .hgtags
   diff --git a/.hgtags b/.hgtags
   --- a/.hgtags
   +++ b/.hgtags
   @@ -1,12 +1,17 @@
    6cee5c8f3e5b4ae1a3996d2f6489c3e08eb5aea7 tbase
   +0000000000000000000000000000000000000000 tbase
    4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t1
   +0000000000000000000000000000000000000000 t1
    4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t2
    4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t3
    4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t2
    0000000000000000000000000000000000000000 t2
    875517b4806a848f942811a315a5bce30804ae85 t5
   +0000000000000000000000000000000000000000 t5
    4f3e9b90005b68b4d8a3f4355cedc302a8364f5c t3
    79505d5360b07e3e79d1052e347e73c02b8afa5b t3
   +0000000000000000000000000000000000000000 t3
    ea918d56be86a4afc5a95312e8b6750e1428d9d2 t7
   +0000000000000000000000000000000000000000 t7
    ea918d56be86a4afc5a95312e8b6750e1428d9d2 t7
    fd3a9e394ce3afb354a496323bf68ac1755a30de t7