merge: simplify a check in checkcopies

mercurial/merge.py

@@ -1,524 +1,524 b''
 # merge.py - directory-level update/merge handling for Mercurial
 #
 # Copyright 2006 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 gettext as _
 from demandload import *
 demandload(globals(), "errno util os tempfile")
 
 def filemerge(repo, fw, fo, wctx, mctx):
     """perform a 3-way merge in the working directory
 
     fw = 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)
         f = os.fdopen(fd, "wb")
         repo.wwrite(ctx.path(), ctx.data(), f)
         f.close()
         return name
 
     fcm = wctx.filectx(fw)
     fco = mctx.filectx(fo)
 
     if not fco.cmp(fcm.data()): # files identical?
         return None
 
     fca = fcm.ancestor(fco)
     if not fca:
         fca = repo.filectx(fw, fileid=nullrev)
     a = repo.wjoin(fw)
     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': fw,
                              'HG_MY_NODE': str(wctx.parents()[0]),
                              'HG_OTHER_NODE': str(mctx)})
     if r:
         repo.ui.warn(_("merging %s failed!\n") % fw)
 
     os.unlink(b)
     os.unlink(c)
     return r
 
 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 local file '%s' differs"\
                                    " from remote version") % 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 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
 
     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
 
     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 checkcopies(c, man):
         '''check possible copies for filectx c'''
         for of in findold(c):
             if of not in man: # original file not in other manifest?
                 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():
                 fullcopy[c.path()] = of # remember for dir rename detection
-                if c == ca and c2 == ca: # no merge needed, ignore copy
+                if c == c2: # 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 {}
 
     dcopies = repo.dirstate.copies()
     copy = {}
     fullcopy = {}
     u1 = nonoverlap(m1, m2, ma)
     u2 = nonoverlap(m2, m1, ma)
     ctx = util.cachefunc(lambda f, n: repo.filectx(f, fileid=n[:20]))
 
     for f in u1:
         checkcopies(ctx(dcopies.get(f, f), m1[f]), m2)
 
     for f in u2:
         checkcopies(ctx(f, m2[f]), m1)
 
     if not fullcopy or not repo.ui.configbool("merge", "followdirs", True):
         return copy
 
     # 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
 
     # 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):]
                     break
 
     return copy
 
 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 = {}
 
     def fmerge(f, f2=None, fa=None):
         """merge executable flags"""
         if not f2:
             f2 = f
             fa = f
         a, b, c = ma.execf(fa), m1.execf(f), m2.execf(f2)
         return ((a^b) | (a^c)) ^ a
 
     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):
         copy = findcopies(repo, m1, m2, ma, pa.rev())
     copied = dict.fromkeys(copy.values())
 
     # Compare manifests
     for f, n in m1.iteritems():
         if partial and not partial(f):
             continue
         if f in m2:
             # are files different?
             if n != m2[f]:
                 a = ma.get(f, nullid)
                 # are both different from the ancestor?
                 if not overwrite and n != a and m2[f] != a:
                     act("versions differ", "m", f, f, f, fmerge(f), False)
                 # are we clobbering?
                 # is remote's version newer?
                 # or are we going back in time and clean?
                 elif overwrite or m2[f] != a or (backwards and not n[20:]):
                     act("remote is newer", "g", f, m2.execf(f))
                 # local is newer, not overwrite, check mode bits
                 elif fmerge(f) != m1.execf(f):
                     act("update permissions", "e", f, m2.execf(f))
             # contents same, check mode bits
             elif m1.execf(f) != m2.execf(f):
                 if overwrite or fmerge(f) != m1.execf(f):
                     act("update permissions", "e", f, m2.execf(f))
         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.execf(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") % f) +
                     _("(k)eep or (d)elete?"), _("[kd]"), _("k")) == _("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.execf(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.execf(f))
             elif n != ma[f]:
                 if repo.ui.prompt(
                     (_("remote changed %s which local deleted\n") % f) +
                     _("(k)eep or (d)elete?"), _("[kd]"), _("k")) == _("k"):
                     act("prompt recreating", "g", f, m2.execf(f))
         else:
             act("remote created", "g", f, m2.execf(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()
     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)
             util.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, flag, move = a[2:]
             r = filemerge(repo, f, f2, wctx, mctx)
             if r > 0:
                 unresolved += 1
             else:
                 if r is None:
                     updated += 1
                 else:
                     merged += 1
                 if f != fd:
                     repo.ui.debug(_("copying %s to %s\n") % (f, fd))
                     repo.wwrite(fd, repo.wread(f))
                     if move:
                         repo.ui.debug(_("removing %s\n") % f)
                         os.unlink(repo.wjoin(f))
             util.set_exec(repo.wjoin(fd), flag)
         elif m == "g": # get
             flag = a[2]
             repo.ui.note(_("getting %s\n") % f)
             t = mctx.filectx(f).data()
             repo.wwrite(f, t)
             util.set_exec(repo.wjoin(f), flag)
             updated += 1
         elif m == "d": # directory rename
             f2, fd, flag = a[2:]
             if f:
                 repo.ui.note(_("moving %s to %s\n") % (f, fd))
                 t = wctx.filectx(f).data()
                 repo.wwrite(fd, t)
                 util.set_exec(repo.wjoin(fd), flag)
                 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)
                 util.set_exec(repo.wjoin(fd), flag)
             updated += 1
         elif m == "e": # exec
             flag = a[2]
             util.set_exec(repo.wjoin(f), flag)
 
     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.update([f], 'r')
             else:
                 repo.dirstate.forget([f])
         elif m == "f": # forget
             repo.dirstate.forget([f])
         elif m == "g": # get
             if branchmerge:
                 repo.dirstate.update([f], 'n', st_mtime=-1)
             else:
                 repo.dirstate.update([f], 'n')
         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.update([fd], 'm')
                 if f != f2: # copy/rename
                     if move:
                         repo.dirstate.update([f], 'r')
                     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.update([fd], 'n', st_size=-1, st_mtime=-1)
                 if move:
                     repo.dirstate.forget([f])
         elif m == "d": # directory rename
             f2, fd, flag = a[2:]
             if branchmerge:
                 repo.dirstate.update([fd], 'a')
                 if f:
                     repo.dirstate.update([f], 'r')
                     repo.dirstate.copy(f, fd)
                 if f2:
                     repo.dirstate.copy(f2, fd)
             else:
                 repo.dirstate.update([fd], 'n')
                 if f:
                     repo.dirstate.forget([f])
 
 def update(repo, node, branchmerge, force, partial, wlock):
     """
     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 = working dir lock, if already held
     """
 
     if not wlock:
         wlock = repo.wlock()
 
     overwrite = force and not branchmerge
     forcemerge = force and branchmerge
     wc = repo.workingctx()
     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)
 
     ### 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:
             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:
             repo.dirstate.setbranch(p2.branch())
         repo.hook('update', parent1=xp1, parent2=xp2, error=stats[3])
 
     return stats