filemerge: pull file-merging code into its own module

mercurial/filemerge.py

@@ -0,0 +1,65 b''
+# filemerge.py - file-level merge handling for Mercurial
+#
+# Copyright 2006, 2007, 2008 Matt Mackall <[e-mail]>
+#
+# This software may be used and distributed according to the terms
+# of the GNU General Public License, incorporated herein by reference.
+
+from node import *
+from i18n import _
+import util, os, tempfile, context
+
+def filemerge(repo, fw, fd, fo, wctx, mctx):
+    """perform a 3-way merge in the working directory
+
+    fw = original filename in the working directory
+    fd = destination filename in the working directory
+    fo = filename in other parent
+    wctx, mctx = working and merge changecontexts
+    """
+
+    def temp(prefix, ctx):
+        pre = "%s~%s." % (os.path.basename(ctx.path()), prefix)
+        (fd, name) = tempfile.mkstemp(prefix=pre)
+        data = repo.wwritedata(ctx.path(), ctx.data())
+        f = os.fdopen(fd, "wb")
+        f.write(data)
+        f.close()
+        return name
+
+    fcm = wctx.filectx(fw)
+    fcmdata = wctx.filectx(fd).data()
+    fco = mctx.filectx(fo)
+
+    if not fco.cmp(fcmdata): # files identical?
+        return None
+
+    fca = fcm.ancestor(fco)
+    if not fca:
+        fca = repo.filectx(fw, fileid=nullrev)
+    a = repo.wjoin(fd)
+    b = temp("base", fca)
+    c = temp("other", fco)
+
+    if fw != fo:
+        repo.ui.status(_("merging %s and %s\n") % (fw, fo))
+    else:
+        repo.ui.status(_("merging %s\n") % fw)
+
+    repo.ui.debug(_("my %s other %s ancestor %s\n") % (fcm, fco, fca))
+
+    cmd = (os.environ.get("HGMERGE") or repo.ui.config("ui", "merge")
+           or "hgmerge")
+    r = util.system('%s "%s" "%s" "%s"' % (cmd, a, b, c), cwd=repo.root,
+                    environ={'HG_FILE': fd,
+                             'HG_MY_NODE': str(wctx.parents()[0]),
+                             'HG_OTHER_NODE': str(mctx),
+                             'HG_MY_ISLINK': fcm.islink(),
+                             'HG_OTHER_ISLINK': fco.islink(),
+                             'HG_BASE_ISLINK': fca.islink(),})
+    if r:
+        repo.ui.warn(_("merging %s failed!\n") % fd)
+
+    os.unlink(b)
+    os.unlink(c)
+    return r

hgext/imerge.py

@@ -1,405 +1,406 b''
 # Copyright (C) 2007 Brendan Cully <[e-mail]>
 # Published under the GNU GPL
 
 '''
 imerge - interactive merge
 '''
 
 from mercurial.i18n import _
 from mercurial.node import *
-from mercurial import commands, cmdutil, dispatch, fancyopts, hg, merge, util
+from mercurial import commands, cmdutil, dispatch, fancyopts
+from mercurial import hg, filemerge, util
 import os, tarfile
 
 class InvalidStateFileException(Exception): pass
 
 class ImergeStateFile(object):
     def __init__(self, im):
         self.im = im
 
     def save(self, dest):
         tf = tarfile.open(dest, 'w:gz')
 
         st = os.path.join(self.im.path, 'status')
         tf.add(st, os.path.join('.hg', 'imerge', 'status'))
 
         for f in self.im.resolved:
             (fd, fo) = self.im.conflicts[f]
             abssrc = self.im.repo.wjoin(fd)
             tf.add(abssrc, fd)
 
         tf.close()
 
     def load(self, source):
         wlock = self.im.repo.wlock()
         lock = self.im.repo.lock()
 
         tf = tarfile.open(source, 'r')
         contents = tf.getnames()
         # tarfile normalizes path separators to '/'
         statusfile = '.hg/imerge/status'
         if statusfile not in contents:
             raise InvalidStateFileException('no status file')
 
         tf.extract(statusfile, self.im.repo.root)
         p1, p2 = self.im.load()
         if self.im.repo.dirstate.parents()[0] != p1.node():
             hg.clean(self.im.repo, p1.node())
         self.im.start(p2.node())
         for tarinfo in tf:
             tf.extract(tarinfo, self.im.repo.root)
         self.im.load()
 
 class Imerge(object):
     def __init__(self, ui, repo):
         self.ui = ui
         self.repo = repo
 
         self.path = repo.join('imerge')
         self.opener = util.opener(self.path)
 
         self.wctx = self.repo.workingctx()
         self.conflicts = {}
         self.resolved = []
 
     def merging(self):
         return len(self.wctx.parents()) > 1
 
     def load(self):
         # status format. \0-delimited file, fields are
         # p1, p2, conflict count, conflict filenames, resolved filenames
         # conflict filenames are tuples of localname, remoteorig, remotenew
 
         statusfile = self.opener('status')
 
         status = statusfile.read().split('\0')
         if len(status) < 3:
             raise util.Abort('invalid imerge status file')
 
         try:
             parents = [self.repo.changectx(n) for n in status[:2]]
         except LookupError:
             raise util.Abort('merge parent %s not in repository' % short(p))
 
         status = status[2:]
         conflicts = int(status.pop(0)) * 3
         self.resolved = status[conflicts:]
         for i in xrange(0, conflicts, 3):
             self.conflicts[status[i]] = (status[i+1], status[i+2])
 
         return parents
 
     def save(self):
         lock = self.repo.lock()
 
         if not os.path.isdir(self.path):
             os.mkdir(self.path)
         statusfile = self.opener('status', 'wb')
 
         out = [hex(n.node()) for n in self.wctx.parents()]
         out.append(str(len(self.conflicts)))
         conflicts = self.conflicts.items()
         conflicts.sort()
         for fw, fd_fo in conflicts:
             out.append(fw)
             out.extend(fd_fo)
         out.extend(self.resolved)
 
         statusfile.write('\0'.join(out))
 
     def remaining(self):
         return [f for f in self.conflicts if f not in self.resolved]
 
     def filemerge(self, fn, interactive=True):
         wlock = self.repo.wlock()
 
         (fd, fo) = self.conflicts[fn]
         p1, p2 = self.wctx.parents()
 
         # this could be greatly improved
         realmerge = os.environ.get('HGMERGE')
         if not interactive:
             os.environ['HGMERGE'] = 'merge'
 
         # The filemerge ancestor algorithm does not work if self.wctx
         # already has two parents (in normal merge it doesn't yet). But
         # this is very dirty.
         self.wctx._parents.pop()
         try:
             # TODO: we should probably revert the file if merge fails
-            return merge.filemerge(self.repo, fn, fd, fo, self.wctx, p2)
+            return filemerge.filemerge(self.repo, fn, fd, fo, self.wctx, p2)
         finally:
             self.wctx._parents.append(p2)
             if realmerge:
                 os.environ['HGMERGE'] = realmerge
             elif not interactive:
                 del os.environ['HGMERGE']
 
     def start(self, rev=None):
-        _filemerge = merge.filemerge
-        def filemerge(repo, fw, fd, fo, wctx, mctx):
+        _filemerge = filemerge.filemerge
+        def filemerge_(repo, fw, fd, fo, wctx, mctx):
             self.conflicts[fw] = (fd, fo)
 
-        merge.filemerge = filemerge
+        filemerge.filemerge = filemerge_
         commands.merge(self.ui, self.repo, rev=rev)
-        merge.filemerge = _filemerge
+        filemerge.filemerge = _filemerge
 
         self.wctx = self.repo.workingctx()
         self.save()
 
     def resume(self):
         self.load()
 
         dp = self.repo.dirstate.parents()
         p1, p2 = self.wctx.parents()
         if p1.node() != dp[0] or p2.node() != dp[1]:
             raise util.Abort('imerge state does not match working directory')
 
     def next(self):
         remaining = self.remaining()
         return remaining and remaining[0]
 
     def resolve(self, files):
         resolved = dict.fromkeys(self.resolved)
         for fn in files:
             if fn not in self.conflicts:
                 raise util.Abort('%s is not in the merge set' % fn)
             resolved[fn] = True
         self.resolved = resolved.keys()
         self.resolved.sort()
         self.save()
         return 0
 
     def unresolve(self, files):
         resolved = dict.fromkeys(self.resolved)
         for fn in files:
             if fn not in resolved:
                 raise util.Abort('%s is not resolved' % fn)
             del resolved[fn]
         self.resolved = resolved.keys()
         self.resolved.sort()
         self.save()
         return 0
 
     def pickle(self, dest):
         '''write current merge state to file to be resumed elsewhere'''
         state = ImergeStateFile(self)
         return state.save(dest)
 
     def unpickle(self, source):
         '''read merge state from file'''
         state = ImergeStateFile(self)
         return state.load(source)
 
 def load(im, source):
     if im.merging():
         raise util.Abort('there is already a merge in progress '
                          '(update -C <rev> to abort it)' )
     m, a, r, d =  im.repo.status()[:4]
     if m or a or r or d:
         raise util.Abort('working directory has uncommitted changes')
 
     rc = im.unpickle(source)
     if not rc:
         status(im)
     return rc
 
 def merge_(im, filename=None, auto=False):
     success = True
     if auto and not filename:
         for fn in im.remaining():
             rc = im.filemerge(fn, interactive=False)
             if rc:
                 success = False
             else:
                 im.resolve([fn])
         if success:
             im.ui.write('all conflicts resolved\n')
         else:
             status(im)
         return 0
 
     if not filename:
         filename = im.next()
         if not filename:
             im.ui.write('all conflicts resolved\n')
             return 0
 
     rc = im.filemerge(filename, interactive=not auto)
     if not rc:
         im.resolve([filename])
         if not im.next():
             im.ui.write('all conflicts resolved\n')
     return rc
 
 def next(im):
     n = im.next()
     if n:
         im.ui.write('%s\n' % n)
     else:
         im.ui.write('all conflicts resolved\n')
     return 0
 
 def resolve(im, *files):
     if not files:
         raise util.Abort('resolve requires at least one filename')
     return im.resolve(files)
 
 def save(im, dest):
     return im.pickle(dest)
 
 def status(im, **opts):
     if not opts.get('resolved') and not opts.get('unresolved'):
         opts['resolved'] = True
         opts['unresolved'] = True
 
     if im.ui.verbose:
         p1, p2 = [short(p.node()) for p in im.wctx.parents()]
         im.ui.note(_('merging %s and %s\n') % (p1, p2))
 
     conflicts = im.conflicts.keys()
     conflicts.sort()
     remaining = dict.fromkeys(im.remaining())
     st = []
     for fn in conflicts:
         if opts.get('no_status'):
             mode = ''
         elif fn in remaining:
             mode = 'U '
         else:
             mode = 'R '
         if ((opts.get('resolved') and fn not in remaining)
             or (opts.get('unresolved') and fn in remaining)):
             st.append((mode, fn))
     st.sort()
     for (mode, fn) in st:
         if im.ui.verbose:
             fo, fd = im.conflicts[fn]
             if fd != fn:
                 fn = '%s (%s)' % (fn, fd)
         im.ui.write('%s%s\n' % (mode, fn))
     if opts.get('unresolved') and not remaining:
         im.ui.write(_('all conflicts resolved\n'))
 
     return 0
 
 def unresolve(im, *files):
     if not files:
         raise util.Abort('unresolve requires at least one filename')
     return im.unresolve(files)
 
 subcmdtable = {
     'load': (load, []),
     'merge':
         (merge_,
          [('a', 'auto', None, _('automatically resolve if possible'))]),
     'next': (next, []),
     'resolve': (resolve, []),
     'save': (save, []),
     'status':
         (status,
          [('n', 'no-status', None, _('hide status prefix')),
           ('', 'resolved', None, _('only show resolved conflicts')),
           ('', 'unresolved', None, _('only show unresolved conflicts'))]),
     'unresolve': (unresolve, [])
 }
 
 def dispatch_(im, args, opts):
     def complete(s, choices):
         candidates = []
         for choice in choices:
             if choice.startswith(s):
                 candidates.append(choice)
         return candidates
 
     c, args = args[0], list(args[1:])
     cmd = complete(c, subcmdtable.keys())
     if not cmd:
         raise cmdutil.UnknownCommand('imerge ' + c)
     if len(cmd) > 1:
         cmd.sort()
         raise cmdutil.AmbiguousCommand('imerge ' + c, cmd)
     cmd = cmd[0]
 
     func, optlist = subcmdtable[cmd]
     opts = {}
     try:
         args = fancyopts.fancyopts(args, optlist, opts)
         return func(im, *args, **opts)
     except fancyopts.getopt.GetoptError, inst:
         raise dispatch.ParseError('imerge', '%s: %s' % (cmd, inst))
     except TypeError:
         raise dispatch.ParseError('imerge', _('%s: invalid arguments') % cmd)
 
 def imerge(ui, repo, *args, **opts):
     '''interactive merge
 
     imerge lets you split a merge into pieces. When you start a merge
     with imerge, the names of all files with conflicts are recorded.
     You can then merge any of these files, and if the merge is
     successful, they will be marked as resolved. When all files are
     resolved, the merge is complete.
 
     If no merge is in progress, hg imerge [rev] will merge the working
     directory with rev (defaulting to the other head if the repository
     only has two heads). You may also resume a saved merge with
     hg imerge load <file>.
 
     If a merge is in progress, hg imerge will default to merging the
     next unresolved file.
 
     The following subcommands are available:
 
     status:
       show the current state of the merge
       options:
         -n --no-status:  do not print the status prefix
            --resolved:   only print resolved conflicts
            --unresolved: only print unresolved conflicts
     next:
       show the next unresolved file merge
     merge [<file>]:
       merge <file>. If the file merge is successful, the file will be
       recorded as resolved. If no file is given, the next unresolved
       file will be merged.
     resolve <file>...:
       mark files as successfully merged
     unresolve <file>...:
       mark files as requiring merging.
     save <file>:
       save the state of the merge to a file to be resumed elsewhere
     load <file>:
       load the state of the merge from a file created by save
     '''
 
     im = Imerge(ui, repo)
 
     if im.merging():
         im.resume()
     else:
         rev = opts.get('rev')
         if rev and args:
             raise util.Abort('please specify just one revision')
 
         if len(args) == 2 and args[0] == 'load':
             pass
         else:
             if args:
                 rev = args[0]
             im.start(rev=rev)
             if opts.get('auto'):
                 args = ['merge', '--auto']
             else:
                 args = ['status']
 
     if not args:
         args = ['merge']
 
     return dispatch_(im, args, opts)
 
 cmdtable = {
     '^imerge':
     (imerge,
      [('r', 'rev', '', _('revision to merge')),
       ('a', 'auto', None, _('automatically merge where possible'))],
       'hg imerge [command]')
 }

mercurial/merge.py

@@ -1,687 +1,632 b''
 # merge.py - directory-level update/merge handling for Mercurial
 #
 # Copyright 2006, 2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
 from node import *
 from i18n import _
-import errno, util, os, tempfile, context, heapq
-
-def filemerge(repo, fw, fd, fo, wctx, mctx):
-    """perform a 3-way merge in the working directory
-
-    fw = original filename in the working directory
-    fd = destination filename in the working directory
-    fo = filename in other parent
-    wctx, mctx = working and merge changecontexts
-    """
-
-    def temp(prefix, ctx):
-        pre = "%s~%s." % (os.path.basename(ctx.path()), prefix)
-        (fd, name) = tempfile.mkstemp(prefix=pre)
-        data = repo.wwritedata(ctx.path(), ctx.data())
-        f = os.fdopen(fd, "wb")
-        f.write(data)
-        f.close()
-        return name
-
-    fcm = wctx.filectx(fw)
-    fcmdata = wctx.filectx(fd).data()
-    fco = mctx.filectx(fo)
-
-    if not fco.cmp(fcmdata): # files identical?
-        return None
-
-    fca = fcm.ancestor(fco)
-    if not fca:
-        fca = repo.filectx(fw, fileid=nullrev)
-    a = repo.wjoin(fd)
-    b = temp("base", fca)
-    c = temp("other", fco)
-
-    if fw != fo:
-        repo.ui.status(_("merging %s and %s\n") % (fw, fo))
-    else:
-        repo.ui.status(_("merging %s\n") % fw)
-
-    repo.ui.debug(_("my %s other %s ancestor %s\n") % (fcm, fco, fca))
-
-    cmd = (os.environ.get("HGMERGE") or repo.ui.config("ui", "merge")
-           or "hgmerge")
-    r = util.system('%s "%s" "%s" "%s"' % (cmd, a, b, c), cwd=repo.root,
-                    environ={'HG_FILE': fd,
-                             'HG_MY_NODE': str(wctx.parents()[0]),
-                             'HG_OTHER_NODE': str(mctx),
-                             'HG_MY_ISLINK': fcm.islink(),
-                             'HG_OTHER_ISLINK': fco.islink(),
-                             'HG_BASE_ISLINK': fca.islink(),})
-    if r:
-        repo.ui.warn(_("merging %s failed!\n") % fd)
-
-    os.unlink(b)
-    os.unlink(c)
-    return r
+import errno, util, os, heapq, filemerge
 
 def checkunknown(wctx, mctx):
     "check for collisions between unknown files and files in mctx"
     man = mctx.manifest()
     for f in wctx.unknown():
         if f in man:
             if mctx.filectx(f).cmp(wctx.filectx(f).data()):
                 raise util.Abort(_("untracked file in working directory differs"
                                    " from file in requested revision: '%s'")
                                  % f)
 
 def checkcollision(mctx):
     "check for case folding collisions in the destination context"
     folded = {}
     for fn in mctx.manifest():
         fold = fn.lower()
         if fold in folded:
             raise util.Abort(_("case-folding collision between %s and %s")
                              % (fn, folded[fold]))
         folded[fold] = fn
 
 def forgetremoved(wctx, mctx):
     """
     Forget removed files
 
     If we're jumping between revisions (as opposed to merging), and if
     neither the working directory nor the target rev has the file,
     then we need to remove it from the dirstate, to prevent the
     dirstate from listing the file when it is no longer in the
     manifest.
     """
 
     action = []
     man = mctx.manifest()
     for f in wctx.deleted() + wctx.removed():
         if f not in man:
             action.append((f, "f"))
 
     return action
 
 def findcopies(repo, m1, m2, ma, limit):
     """
     Find moves and copies between m1 and m2 back to limit linkrev
     """
 
     def nonoverlap(d1, d2, d3):
         "Return list of elements in d1 not in d2 or d3"
         l = [d for d in d1 if d not in d3 and d not in d2]
         l.sort()
         return l
 
     def dirname(f):
         s = f.rfind("/")
         if s == -1:
             return ""
         return f[:s]
 
     def dirs(files):
         d = {}
         for f in files:
             f = dirname(f)
             while f not in d:
                 d[f] = True
                 f = dirname(f)
         return d
 
     wctx = repo.workingctx()
 
     def makectx(f, n):
         if len(n) == 20:
             return repo.filectx(f, fileid=n)
         return wctx.filectx(f)
     ctx = util.cachefunc(makectx)
 
     def findold(fctx):
         "find files that path was copied from, back to linkrev limit"
         old = {}
         seen = {}
         orig = fctx.path()
         visit = [fctx]
         while visit:
             fc = visit.pop()
             s = str(fc)
             if s in seen:
                 continue
             seen[s] = 1
             if fc.path() != orig and fc.path() not in old:
                 old[fc.path()] = 1
             if fc.rev() < limit:
                 continue
             visit += fc.parents()
 
         old = old.keys()
         old.sort()
         return old
 
     copy = {}
     fullcopy = {}
     diverge = {}
 
     def checkcopies(c, man, aman):
         '''check possible copies for filectx c'''
         for of in findold(c):
             fullcopy[c.path()] = of # remember for dir rename detection
             if of not in man: # original file not in other manifest?
                 if of in ma:
                     diverge.setdefault(of, []).append(c.path())
                 continue
             # if the original file is unchanged on the other branch,
             # no merge needed
             if man[of] == aman.get(of):
                 continue
             c2 = ctx(of, man[of])
             ca = c.ancestor(c2)
             if not ca: # unrelated?
                 continue
             # named changed on only one side?
             if ca.path() == c.path() or ca.path() == c2.path():
                 if c == ca and c2 == ca: # no merge needed, ignore copy
                     continue
                 copy[c.path()] = of
 
     if not repo.ui.configbool("merge", "followcopies", True):
         return {}, {}
 
     # avoid silly behavior for update from empty dir
     if not m1 or not m2 or not ma:
         return {}, {}
 
     repo.ui.debug(_("  searching for copies back to rev %d\n") % limit)
 
     u1 = nonoverlap(m1, m2, ma)
     u2 = nonoverlap(m2, m1, ma)
 
     if u1:
         repo.ui.debug(_("  unmatched files in local:\n   %s\n")
                       % "\n   ".join(u1))
     if u2:
         repo.ui.debug(_("  unmatched files in other:\n   %s\n")
                       % "\n   ".join(u2))
 
     for f in u1:
         checkcopies(ctx(f, m1[f]), m2, ma)
 
     for f in u2:
         checkcopies(ctx(f, m2[f]), m1, ma)
 
     diverge2 = {}
     for of, fl in diverge.items():
         if len(fl) == 1:
             del diverge[of] # not actually divergent
         else:
             diverge2.update(dict.fromkeys(fl)) # reverse map for below
 
     if fullcopy:
         repo.ui.debug(_("  all copies found (* = to merge, ! = divergent):\n"))
         for f in fullcopy:
             note = ""
             if f in copy: note += "*"
             if f in diverge2: note += "!"
             repo.ui.debug(_("   %s -> %s %s\n") % (f, fullcopy[f], note))
 
     del diverge2
 
     if not fullcopy or not repo.ui.configbool("merge", "followdirs", True):
         return copy, diverge
 
     repo.ui.debug(_("  checking for directory renames\n"))
 
     # generate a directory move map
     d1, d2 = dirs(m1), dirs(m2)
     invalid = {}
     dirmove = {}
 
     # examine each file copy for a potential directory move, which is
     # when all the files in a directory are moved to a new directory
     for dst, src in fullcopy.items():
         dsrc, ddst = dirname(src), dirname(dst)
         if dsrc in invalid:
             # already seen to be uninteresting
             continue
         elif dsrc in d1 and ddst in d1:
             # directory wasn't entirely moved locally
             invalid[dsrc] = True
         elif dsrc in d2 and ddst in d2:
             # directory wasn't entirely moved remotely
             invalid[dsrc] = True
         elif dsrc in dirmove and dirmove[dsrc] != ddst:
             # files from the same directory moved to two different places
             invalid[dsrc] = True
         else:
             # looks good so far
             dirmove[dsrc + "/"] = ddst + "/"
 
     for i in invalid:
         if i in dirmove:
             del dirmove[i]
 
     del d1, d2, invalid
 
     if not dirmove:
         return copy, diverge
 
     for d in dirmove:
         repo.ui.debug(_("  dir %s -> %s\n") % (d, dirmove[d]))
 
     # check unaccounted nonoverlapping files against directory moves
     for f in u1 + u2:
         if f not in fullcopy:
             for d in dirmove:
                 if f.startswith(d):
                     # new file added in a directory that was moved, move it
                     copy[f] = dirmove[d] + f[len(d):]
                     repo.ui.debug(_("  file %s -> %s\n") % (f, copy[f]))
                     break
 
     return copy, diverge
 
 def symmetricdifference(repo, rev1, rev2):
     """symmetric difference of the sets of ancestors of rev1 and rev2
 
     I.e. revisions that are ancestors of rev1 or rev2, but not both.
     """
     # basic idea:
     # - mark rev1 and rev2 with different colors
     # - walk the graph in topological order with the help of a heap;
     #   for each revision r:
     #     - if r has only one color, we want to return it
     #     - add colors[r] to its parents
     #
     # We keep track of the number of revisions in the heap that
     # we may be interested in.  We stop walking the graph as soon
     # as this number reaches 0.
     WHITE = 1
     BLACK = 2
     ALLCOLORS = WHITE | BLACK
     colors = {rev1: WHITE, rev2: BLACK}
 
     cl = repo.changelog
 
     visit = [-rev1, -rev2]
     heapq.heapify(visit)
     n_wanted = len(visit)
     ret = []
 
     while n_wanted:
         r = -heapq.heappop(visit)
         wanted = colors[r] != ALLCOLORS
         n_wanted -= wanted
         if wanted:
             ret.append(r)
 
         for p in cl.parentrevs(r):
             if p == nullrev:
                 continue
             if p not in colors:
                 # first time we see p; add it to visit
                 n_wanted += wanted
                 colors[p] = colors[r]
                 heapq.heappush(visit, -p)
             elif colors[p] != ALLCOLORS and colors[p] != colors[r]:
                 # at first we thought we wanted p, but now
                 # we know we don't really want it
                 n_wanted -= 1
                 colors[p] |= colors[r]
 
         del colors[r]
 
     return ret
 
 def manifestmerge(repo, p1, p2, pa, overwrite, partial):
     """
     Merge p1 and p2 with ancestor ma and generate merge action list
 
     overwrite = whether we clobber working files
     partial = function to filter file lists
     """
 
     repo.ui.note(_("resolving manifests\n"))
     repo.ui.debug(_(" overwrite %s partial %s\n") % (overwrite, bool(partial)))
     repo.ui.debug(_(" ancestor %s local %s remote %s\n") % (pa, p1, p2))
 
     m1 = p1.manifest()
     m2 = p2.manifest()
     ma = pa.manifest()
     backwards = (pa == p2)
     action = []
     copy = {}
     diverge = {}
 
     def fmerge(f, f2=None, fa=None):
         """merge flags"""
         if not f2:
             f2 = f
             fa = f
         a, m, n = ma.flags(fa), m1.flags(f), m2.flags(f2)
         if m == n: # flags agree
             return m # unchanged
         if m and n: # flags are set but don't agree
             if not a: # both differ from parent
                 r = repo.ui.prompt(
                     _(" conflicting flags for %s\n"
                       "(n)one, e(x)ec or sym(l)ink?") % f, "[nxl]", "n")
                 return r != "n" and r or ''
             if m == a:
                 return n # changed from m to n
             return m # changed from n to m
         if m and m != a: # changed from a to m
             return m
         if n and n != a: # changed from a to n
             return n
         return '' # flag was cleared
 
     def act(msg, m, f, *args):
         repo.ui.debug(" %s: %s -> %s\n" % (f, msg, m))
         action.append((f, m) + args)
 
     if not (backwards or overwrite):
         rev1 = p1.rev()
         if rev1 is None:
             # p1 is a workingctx
             rev1 = p1.parents()[0].rev()
         limit = min(symmetricdifference(repo, rev1, p2.rev()))
         copy, diverge = findcopies(repo, m1, m2, ma, limit)
 
     for of, fl in diverge.items():
         act("divergent renames", "dr", of, fl)
 
     copied = dict.fromkeys(copy.values())
 
     # Compare manifests
     for f, n in m1.iteritems():
         if partial and not partial(f):
             continue
         if f in m2:
             if overwrite or backwards:
                 rflags = m2.flags(f)
             else:
                 rflags = fmerge(f)
             # are files different?
             if n != m2[f]:
                 a = ma.get(f, nullid)
                 # are we clobbering?
                 if overwrite:
                     act("clobbering", "g", f, rflags)
                 # or are we going back in time and clean?
                 elif backwards and not n[20:]:
                     act("reverting", "g", f, rflags)
                 # are both different from the ancestor?
                 elif n != a and m2[f] != a:
                     act("versions differ", "m", f, f, f, rflags, False)
                 # is remote's version newer?
                 elif m2[f] != a:
                     act("remote is newer", "g", f, rflags)
                 # local is newer, not overwrite, check mode bits
                 elif m1.flags(f) != rflags:
                     act("update permissions", "e", f, rflags)
             # contents same, check mode bits
             elif m1.flags(f) != rflags:
                 act("update permissions", "e", f, rflags)
         elif f in copied:
             continue
         elif f in copy:
             f2 = copy[f]
             if f2 not in m2: # directory rename
                 act("remote renamed directory to " + f2, "d",
                     f, None, f2, m1.flags(f))
             elif f2 in m1: # case 2 A,B/B/B
                 act("local copied to " + f2, "m",
                     f, f2, f, fmerge(f, f2, f2), False)
             else: # case 4,21 A/B/B
                 act("local moved to " + f2, "m",
                     f, f2, f, fmerge(f, f2, f2), False)
         elif f in ma:
             if n != ma[f] and not overwrite:
                 if repo.ui.prompt(
                     _(" local changed %s which remote deleted\n"
                       "use (c)hanged version or (d)elete?") % f,
                     _("[cd]"), _("c")) == _("d"):
                     act("prompt delete", "r", f)
             else:
                 act("other deleted", "r", f)
         else:
             # file is created on branch or in working directory
             if (overwrite and n[20:] != "u") or (backwards and not n[20:]):
                 act("remote deleted", "r", f)
 
     for f, n in m2.iteritems():
         if partial and not partial(f):
             continue
         if f in m1:
             continue
         if f in copied:
             continue
         if f in copy:
             f2 = copy[f]
             if f2 not in m1: # directory rename
                 act("local renamed directory to " + f2, "d",
                     None, f, f2, m2.flags(f))
             elif f2 in m2: # rename case 1, A/A,B/A
                 act("remote copied to " + f, "m",
                     f2, f, f, fmerge(f2, f, f2), False)
             else: # case 3,20 A/B/A
                 act("remote moved to " + f, "m",
                     f2, f, f, fmerge(f2, f, f2), True)
         elif f in ma:
             if overwrite or backwards:
                 act("recreating", "g", f, m2.flags(f))
             elif n != ma[f]:
                 if repo.ui.prompt(
                     _("remote changed %s which local deleted\n"
                       "use (c)hanged version or leave (d)eleted?") % f,
                     _("[cd]"), _("c")) == _("c"):
                     act("prompt recreating", "g", f, m2.flags(f))
         else:
             act("remote created", "g", f, m2.flags(f))
 
     return action
 
 def applyupdates(repo, action, wctx, mctx):
     "apply the merge action list to the working directory"
 
     updated, merged, removed, unresolved = 0, 0, 0, 0
     action.sort()
     # prescan for copy/renames
     for a in action:
         f, m = a[:2]
         if m == 'm': # merge
             f2, fd, flags, move = a[2:]
             if f != fd:
                 repo.ui.debug(_("copying %s to %s\n") % (f, fd))
                 repo.wwrite(fd, repo.wread(f), flags)
 
     audit_path = util.path_auditor(repo.root)
 
     for a in action:
         f, m = a[:2]
         if f and f[0] == "/":
             continue
         if m == "r": # remove
             repo.ui.note(_("removing %s\n") % f)
             audit_path(f)
             try:
                 util.unlink(repo.wjoin(f))
             except OSError, inst:
                 if inst.errno != errno.ENOENT:
                     repo.ui.warn(_("update failed to remove %s: %s!\n") %
                                  (f, inst.strerror))
             removed += 1
         elif m == "m": # merge
             f2, fd, flags, move = a[2:]
-            r = filemerge(repo, f, fd, f2, wctx, mctx)
+            r = filemerge.filemerge(repo, f, fd, f2, wctx, mctx)
             if r > 0:
                 unresolved += 1
             else:
                 if r is None:
                     updated += 1
                 else:
                     merged += 1
             util.set_flags(repo.wjoin(fd), flags)
             if f != fd and move and util.lexists(repo.wjoin(f)):
                 repo.ui.debug(_("removing %s\n") % f)
                 os.unlink(repo.wjoin(f))
         elif m == "g": # get
             flags = a[2]
             repo.ui.note(_("getting %s\n") % f)
             t = mctx.filectx(f).data()
             repo.wwrite(f, t, flags)
             updated += 1
         elif m == "d": # directory rename
             f2, fd, flags = a[2:]
             if f:
                 repo.ui.note(_("moving %s to %s\n") % (f, fd))
                 t = wctx.filectx(f).data()
                 repo.wwrite(fd, t, flags)
                 util.unlink(repo.wjoin(f))
             if f2:
                 repo.ui.note(_("getting %s to %s\n") % (f2, fd))
                 t = mctx.filectx(f2).data()
                 repo.wwrite(fd, t, flags)
             updated += 1
         elif m == "dr": # divergent renames
             fl = a[2]
             repo.ui.warn("warning: detected divergent renames of %s to:\n" % f)
             for nf in fl:
                 repo.ui.warn(" %s\n" % nf)
         elif m == "e": # exec
             flags = a[2]
             util.set_flags(repo.wjoin(f), flags)
 
     return updated, merged, removed, unresolved
 
 def recordupdates(repo, action, branchmerge):
     "record merge actions to the dirstate"
 
     for a in action:
         f, m = a[:2]
         if m == "r": # remove
             if branchmerge:
                 repo.dirstate.remove(f)
             else:
                 repo.dirstate.forget(f)
         elif m == "f": # forget
             repo.dirstate.forget(f)
         elif m in "ge": # get or exec change
             if branchmerge:
                 repo.dirstate.normaldirty(f)
             else:
                 repo.dirstate.normal(f)
         elif m == "m": # merge
             f2, fd, flag, move = a[2:]
             if branchmerge:
                 # We've done a branch merge, mark this file as merged
                 # so that we properly record the merger later
                 repo.dirstate.merge(fd)
                 if f != f2: # copy/rename
                     if move:
                         repo.dirstate.remove(f)
                     if f != fd:
                         repo.dirstate.copy(f, fd)
                     else:
                         repo.dirstate.copy(f2, fd)
             else:
                 # We've update-merged a locally modified file, so
                 # we set the dirstate to emulate a normal checkout
                 # of that file some time in the past. Thus our
                 # merge will appear as a normal local file
                 # modification.
                 repo.dirstate.normallookup(fd)
                 if move:
                     repo.dirstate.forget(f)
         elif m == "d": # directory rename
             f2, fd, flag = a[2:]
             if not f2 and f not in repo.dirstate:
                 # untracked file moved
                 continue
             if branchmerge:
                 repo.dirstate.add(fd)
                 if f:
                     repo.dirstate.remove(f)
                     repo.dirstate.copy(f, fd)
                 if f2:
                     repo.dirstate.copy(f2, fd)
             else:
                 repo.dirstate.normal(fd)
                 if f:
                     repo.dirstate.forget(f)
 
 def update(repo, node, branchmerge, force, partial):
     """
     Perform a merge between the working directory and the given node
 
     branchmerge = whether to merge between branches
     force = whether to force branch merging or file overwriting
     partial = a function to filter file lists (dirstate not updated)
     """
 
     wlock = repo.wlock()
     try:
         wc = repo.workingctx()
         if node is None:
             # tip of current branch
             try:
                 node = repo.branchtags()[wc.branch()]
             except KeyError:
                 if wc.branch() == "default": # no default branch!
                     node = repo.lookup("tip") # update to tip
                 else:
                     raise util.Abort(_("branch %s not found") % wc.branch())
         overwrite = force and not branchmerge
         forcemerge = force and branchmerge
         pl = wc.parents()
         p1, p2 = pl[0], repo.changectx(node)
         pa = p1.ancestor(p2)
         fp1, fp2, xp1, xp2 = p1.node(), p2.node(), str(p1), str(p2)
         fastforward = False
 
         ### check phase
         if not overwrite and len(pl) > 1:
             raise util.Abort(_("outstanding uncommitted merges"))
         if pa == p1 or pa == p2: # is there a linear path from p1 to p2?
             if branchmerge:
                 if p1.branch() != p2.branch() and pa != p2:
                     fastforward = True
                 else:
                     raise util.Abort(_("there is nothing to merge, just use "
                                        "'hg update' or look at 'hg heads'"))
         elif not (overwrite or branchmerge):
             raise util.Abort(_("update spans branches, use 'hg merge' "
                                "or 'hg update -C' to lose changes"))
         if branchmerge and not forcemerge:
             if wc.files():
                 raise util.Abort(_("outstanding uncommitted changes"))
 
         ### calculate phase
         action = []
         if not force:
             checkunknown(wc, p2)
         if not util.checkfolding(repo.path):
             checkcollision(p2)
         if not branchmerge:
             action += forgetremoved(wc, p2)
         action += manifestmerge(repo, wc, p2, pa, overwrite, partial)
 
         ### apply phase
         if not branchmerge: # just jump to the new rev
             fp1, fp2, xp1, xp2 = fp2, nullid, xp2, ''
         if not partial:
             repo.hook('preupdate', throw=True, parent1=xp1, parent2=xp2)
 
         stats = applyupdates(repo, action, wc, p2)
 
         if not partial:
             recordupdates(repo, action, branchmerge)
             repo.dirstate.setparents(fp1, fp2)
             if not branchmerge and not fastforward:
                 repo.dirstate.setbranch(p2.branch())
             repo.hook('update', parent1=xp1, parent2=xp2, error=stats[3])
 
         return stats
     finally:
         del wlock