Make fast-forward merges full merges

mercurial/merge.py

@@ -1,544 +1,543 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 _
 import errno, util, os, tempfile, context
 
 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)
         data = repo.wwritedata(ctx.path(), ctx.data())
         f = os.fdopen(fd, "wb")
         f.write(data)
         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 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 = {}
 
     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 or 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 {}
 
     u1 = nonoverlap(m1, m2, ma)
     u2 = nonoverlap(m2, m1, ma)
 
     for f in u1:
         checkcopies(ctx(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 flags"""
         if not f2:
             f2 = f
             fa = f
         a, b, c = ma.execf(fa), m1.execf(f), m2.execf(f2)
         if ((a^b) | (a^c)) ^ a:
             return 'x'
         a, b, c = ma.linkf(fa), m1.linkf(f), m2.linkf(f2)
         if ((a^b) | (a^c)) ^ a:
             return 'l'
         return ''
 
     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.flags(f))
                 # local is newer, not overwrite, check mode bits
                 elif fmerge(f) != m1.flags(f):
                     act("update permissions", "e", f, m2.flags(f))
             # contents same, check mode bits
             elif m1.flags(f) != m2.flags(f):
                 if overwrite or fmerge(f) != m1.flags(f):
                     act("update permissions", "e", f, m2.flags(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.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") % 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.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") % f) +
                     _("(k)eep or (d)elete?"), _("[kd]"), _("k")) == _("k"):
                     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()
     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, flags, 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), flags)
                     if move:
                         repo.ui.debug(_("removing %s\n") % f)
                         os.unlink(repo.wjoin(f))
             util.set_exec(repo.wjoin(fd), "x" in flags)
         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 == "e": # exec
             flags = a[2]
             util.set_exec(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.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()
 
     wc = repo.workingctx()
     if node is None:
         # tip of current branch
         try:
             node = repo.branchtags()[wc.branch()]
         except KeyError:
             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():
                 fastforward = True
-                branchmerge = False
             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
 

tests/test-newbranch.out

@@ -1,106 +1,108 b''
 marked working directory as branch foo
 foo
 marked working directory as branch bar
 % branch shadowing
 abort: a branch of the same name already exists (use --force to override)
 marked working directory as branch default
 0 files updated, 0 files merged, 0 files removed, 0 files unresolved
 foo
 0 files updated, 0 files merged, 0 files removed, 0 files unresolved
 (branch merge, don't forget to commit)
 foo
 changeset:   5:5f8fb06e083e
 branch:      foo
 tag:         tip
 parent:      4:4909a3732169
 parent:      3:bf1bc2f45e83
 user:        test
 date:        Mon Jan 12 13:46:40 1970 +0000
 summary:     merge
 
 changeset:   4:4909a3732169
 branch:      foo
 parent:      1:b699b1cec9c2
 user:        test
 date:        Mon Jan 12 13:46:40 1970 +0000
 summary:     modify a branch
 
 changeset:   3:bf1bc2f45e83
 user:        test
 date:        Mon Jan 12 13:46:40 1970 +0000
 summary:     clear branch name
 
 changeset:   2:67ec16bde7f1
 branch:      bar
 user:        test
 date:        Mon Jan 12 13:46:40 1970 +0000
 summary:     change branch name
 
 changeset:   1:b699b1cec9c2
 branch:      foo
 user:        test
 date:        Mon Jan 12 13:46:40 1970 +0000
 summary:     add branch name
 
 changeset:   0:be8523e69bf8
 user:        test
 date:        Mon Jan 12 13:46:40 1970 +0000
 summary:     initial
 
 foo                            5:5f8fb06e083e
 default                        3:bf1bc2f45e83
 bar                            2:67ec16bde7f1
 foo
 default
 bar
 % test for invalid branch cache
 rolling back last transaction
 changeset:   4:4909a3732169
 branch:      foo
 tag:         tip
 parent:      1:b699b1cec9c2
 user:        test
 date:        Mon Jan 12 13:46:40 1970 +0000
 summary:     modify a branch
 
 Invalid branch cache: unknown tip
 changeset:   4:4909a3732169c0c20011c4f4b8fdff4e3d89b23f
 branch:      foo
 tag:         tip
 parent:      1:b699b1cec9c2966b3700de4fef0dc123cd754c31
 parent:      -1:0000000000000000000000000000000000000000
 manifest:    4:d01b250baaa05909152f7ae07d7a649deea0df9a
 user:        test
 date:        Mon Jan 12 13:46:40 1970 +0000
 files:       a
 extra:       branch=foo
 description:
 modify a branch
 
 
 4:4909a3732169
 4909a3732169c0c20011c4f4b8fdff4e3d89b23f 4
 bf1bc2f45e834c75404d0ddab57d53beab56e2f8 default
 4909a3732169c0c20011c4f4b8fdff4e3d89b23f foo
 67ec16bde7f1575d523313b9bca000f6a6f12dca bar
 % update with no arguments: tipmost revision of the current branch
 bf1bc2f45e83
 4909a3732169 (foo) tip
 marked working directory as branch foobar
 abort: branch foobar not found
 % fastforward merge
 marked working directory as branch ff
 adding ff
 0 files updated, 0 files merged, 1 files removed, 0 files unresolved
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 (branch merge, don't forget to commit)
 foo
-changeset:   6:9cc105113eeb
+changeset:   6:f0c74f92a385
 branch:      foo
 tag:         tip
+parent:      4:4909a3732169
+parent:      5:c420d2121b71
 user:        test
 date:        Mon Jan 12 13:46:40 1970 +0000
 summary:     Merge ff into foo
 
 a
 ff