merge: add backwards variable

mercurial/merge.py

@@ -1,339 +1,342 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(), "util os tempfile")
 
 def fmerge(f, local, other, ancestor):
     """merge executable flags"""
     a, b, c = ancestor.execf(f), local.execf(f), other.execf(f)
     return ((a^b) | (a^c)) ^ a
 
 def merge3(repo, fn, my, other, p1, p2):
     """perform a 3-way merge in the working directory"""
 
     def temp(prefix, node):
         pre = "%s~%s." % (os.path.basename(fn), prefix)
         (fd, name) = tempfile.mkstemp(prefix=pre)
         f = os.fdopen(fd, "wb")
         repo.wwrite(fn, fl.read(node), f)
         f.close()
         return name
 
     fl = repo.file(fn)
     base = fl.ancestor(my, other)
     a = repo.wjoin(fn)
     b = temp("base", base)
     c = temp("other", other)
 
     repo.ui.note(_("resolving %s\n") % fn)
     repo.ui.debug(_("file %s: my %s other %s ancestor %s\n") %
                           (fn, short(my), short(other), short(base)))
 
     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': fn,
                              'HG_MY_NODE': p1,
                              'HG_OTHER_NODE': p2,
                              'HG_FILE_MY_NODE': hex(my),
                              'HG_FILE_OTHER_NODE': hex(other),
                              'HG_FILE_BASE_NODE': hex(base)})
     if r:
         repo.ui.warn(_("merging %s failed!\n") % fn)
 
     os.unlink(b)
     os.unlink(c)
     return r
 
 def update(repo, node, branchmerge=False, force=False, partial=None,
            wlock=None, show_stats=True, remind=True):
 
     overwrite = force and not branchmerge
     forcemerge = force and branchmerge
 
     if not wlock:
         wlock = repo.wlock()
 
     ### check phase
 
     pl = repo.dirstate.parents()
     if not overwrite and pl[1] != nullid:
         raise util.Abort(_("outstanding uncommitted merges"))
 
     p1, p2 = pl[0], node
     pa = repo.changelog.ancestor(p1, p2)
 
+    # are we going backwards?
+    backwards = (pa == p2)
+
     # is there a linear path from p1 to p2?
     linear_path = (pa == p1 or pa == p2)
     if branchmerge and linear_path:
         raise util.Abort(_("there is nothing to merge, just use "
                            "'hg update' or look at 'hg heads'"))
 
     if not overwrite and not linear_path and not branchmerge:
         raise util.Abort(_("update spans branches, use 'hg merge' "
                            "or 'hg update -C' to lose changes"))
 
     modified, added, removed, deleted, unknown = repo.status()[:5]
     if branchmerge and not forcemerge:
         if modified or added or removed:
             raise util.Abort(_("outstanding uncommitted changes"))
 
     m1n = repo.changelog.read(p1)[0]
     m2n = repo.changelog.read(p2)[0]
     man = repo.manifest.ancestor(m1n, m2n)
     m1 = repo.manifest.read(m1n)
     m2 = repo.manifest.read(m2n).copy()
     ma = repo.manifest.read(man)
 
     if not force:
         for f in unknown:
             if f in m2:
                 if repo.file(f).cmp(m2[f], repo.wread(f)):
                     raise util.Abort(_("'%s' already exists in the working"
                                        " dir and differs from remote") % f)
 
     # resolve the manifest to determine which files
     # we care about merging
     repo.ui.note(_("resolving manifests\n"))
     repo.ui.debug(_(" overwrite %s branchmerge %s partial %s linear %s\n") %
                   (overwrite, branchmerge, bool(partial), linear_path))
     repo.ui.debug(_(" ancestor %s local %s remote %s\n") %
                   (short(man), short(m1n), short(m2n)))
 
     merge = {}
     get = {}
     remove = []
     forget = []
 
     # construct a working dir manifest
     mw = m1.copy()
     umap = dict.fromkeys(unknown)
 
     for f in added + modified + unknown:
         mw[f] = ""
         # is the wfile new and matches m2?
         if (f not in m1 and f in m2 and
             not repo.file(f).cmp(m2[f], repo.wread(f))):
             mw[f] = m2[f]
 
         mw.set(f, util.is_exec(repo.wjoin(f), mw.execf(f)))
 
     for f in deleted + removed:
         if f in mw:
             del mw[f]
 
         # 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.
         if linear_path and f not in m2:
             forget.append(f)
 
     # Compare manifests
     for f, n in mw.iteritems():
         if partial and not partial(f):
             continue
         if f in m2:
             s = 0
 
             # are files different?
             if n != m2[f]:
                 a = ma.get(f, nullid)
                 # are both different from the ancestor?
                 if n != a and m2[f] != a:
                     repo.ui.debug(_(" %s versions differ, resolve\n") % f)
                     merge[f] = (fmerge(f, mw, m2, ma), m1.get(f, nullid), m2[f])
                     s = 1
                 # are we clobbering?
                 # is remote's version newer?
-                # or are we going back in time?
-                elif overwrite or m2[f] != a or (p2 == pa and mw[f] == m1[f]):
+                # or are we going back in time and clean?
+                elif overwrite or m2[f] != a or (backwards and mw[f] == m1[f]):
                     repo.ui.debug(_(" remote %s is newer, get\n") % f)
                     get[f] = (m2.execf(f), m2[f])
                     s = 1
             elif f in umap or f in added:
                 # this unknown file is the same as the checkout
                 # we need to reset the dirstate if the file was added
                 get[f] = (m2.execf(f), m2[f])
 
             if not s and mw.execf(f) != m2.execf(f):
                 if overwrite:
                     repo.ui.debug(_(" updating permissions for %s\n") % f)
                     util.set_exec(repo.wjoin(f), m2.execf(f))
                 else:
                     if fmerge(f, mw, m2, ma) != mw.execf(f):
                         repo.ui.debug(_(" updating permissions for %s\n")
                                       % f)
                         util.set_exec(repo.wjoin(f), mode)
             del m2[f]
         elif f in ma:
             if n != ma[f]:
                 r = _("d")
                 if not overwrite and (linear_path or branchmerge):
                     r = repo.ui.prompt(
                         (_(" local changed %s which remote deleted\n") % f) +
                          _("(k)eep or (d)elete?"), _("[kd]"), _("k"))
                 if r == _("d"):
                     remove.append(f)
             else:
                 repo.ui.debug(_("other deleted %s\n") % f)
                 remove.append(f) # other deleted it
         else:
             # file is created on branch or in working directory
             if overwrite and f not in umap:
                 repo.ui.debug(_("remote deleted %s, clobbering\n") % f)
                 remove.append(f)
             elif n == m1.get(f, nullid): # same as parent
-                if p2 == pa: # going backwards?
+                if backwards:
                     repo.ui.debug(_("remote deleted %s\n") % f)
                     remove.append(f)
                 else:
                     repo.ui.debug(_("local modified %s, keeping\n") % f)
             else:
                 repo.ui.debug(_("working dir created %s, keeping\n") % f)
 
     for f, n in m2.iteritems():
         if partial and not partial(f):
             continue
         if f[0] == "/":
             continue
         if f in ma and n != ma[f]:
             r = _("k")
             if not overwrite and (linear_path or branchmerge):
                 r = repo.ui.prompt(
                     (_("remote changed %s which local deleted\n") % f) +
                      _("(k)eep or (d)elete?"), _("[kd]"), _("k"))
             if r == _("k"):
                 get[f] = (m2.execf(f), n)
         elif f not in ma:
             repo.ui.debug(_("remote created %s\n") % f)
             get[f] = (m2.execf(f), n)
         else:
-            if overwrite or p2 == pa: # going backwards?
+            if overwrite or backwards:
                 repo.ui.debug(_("local deleted %s, recreating\n") % f)
                 get[f] = (m2.execf(f), n)
             else:
                 repo.ui.debug(_("local deleted %s\n") % f)
 
     del mw, m1, m2, ma
 
     ### apply phase
 
     if overwrite:
         for f in merge:
             get[f] = merge[f][:2]
         merge = {}
 
     if linear_path or overwrite:
         # we don't need to do any magic, just jump to the new rev
         p1, p2 = p2, nullid
 
     xp1 = hex(p1)
     xp2 = hex(p2)
     if p2 == nullid: xxp2 = ''
     else: xxp2 = xp2
 
     repo.hook('preupdate', throw=True, parent1=xp1, parent2=xxp2)
 
     # get the files we don't need to change
     files = get.keys()
     files.sort()
     for f in files:
         flag, node = get[f]
         if f[0] == "/":
             continue
         repo.ui.note(_("getting %s\n") % f)
         t = repo.file(f).read(node)
         repo.wwrite(f, t)
         util.set_exec(repo.wjoin(f), flag)
 
     # merge the tricky bits
     unresolved = []
     files = merge.keys()
     files.sort()
     for f in files:
         repo.ui.status(_("merging %s\n") % f)
         flag, my, other = merge[f]
         ret = merge3(repo, f, my, other, xp1, xp2)
         if ret:
             unresolved.append(f)
         util.set_exec(repo.wjoin(f), flag)
 
     remove.sort()
     for f in 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))
 
     # update dirstate
     if not partial:
         repo.dirstate.setparents(p1, p2)
         repo.dirstate.forget(forget)
         if branchmerge:
             repo.dirstate.update(remove, 'r')
         else:
             repo.dirstate.forget(remove)
 
         files = get.keys()
         files.sort()
         for f in files:
             if branchmerge:
                 repo.dirstate.update([f], 'n', st_mtime=-1)
             else:
                 repo.dirstate.update([f], 'n')
 
         files = merge.keys()
         files.sort()
         for f in files:
             if branchmerge:
                 # We've done a branch merge, mark this file as merged
                 # so that we properly record the merger later
                 repo.dirstate.update([f], 'm')
             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.
                 fl = repo.file(f)
                 f_len = fl.size(fl.rev(other))
                 repo.dirstate.update([f], 'n', st_size=f_len, st_mtime=-1)
 
     if show_stats:
         stats = ((len(get), _("updated")),
                  (len(merge) - len(unresolved), _("merged")),
                  (len(remove), _("removed")),
                  (len(unresolved), _("unresolved")))
         note = ", ".join([_("%d files %s") % s for s in stats])
         repo.ui.status("%s\n" % note)
     if not partial:
         if branchmerge:
             if unresolved:
                 repo.ui.status(_("There are unresolved merges,"
                                 " you can redo the full merge using:\n"
                                 "  hg update -C %s\n"
                                 "  hg merge %s\n"
                                 % (repo.changelog.rev(p1),
                                     repo.changelog.rev(p2))))
             elif remind:
                 repo.ui.status(_("(branch merge, don't forget to commit)\n"))
         elif unresolved:
             repo.ui.status(_("There are unresolved merges with"
                              " locally modified files.\n"))
 
     repo.hook('update', parent1=xp1, parent2=xxp2, error=len(unresolved))
     return len(unresolved)