copies,

# code imported from Mercurial core at ae17555ef93f + patch

def fixedcopytracing(repo, c1, c2, base):

    """A complete copy-patse of copies._fullcopytrace with a one line fix to

    handle when the base is not parent of both c1 and c2. This should be

    converted in a compat function once https://phab.mercurial-scm.org/D3896

    gets in and once we drop support for 4.7, this should be removed."""

    from mercurial import pathutil

    # In certain scenarios (e.g. graft, update or rebase), base can be

    # overridden We still need to know a real common ancestor in this case We

    # can't just compute _c1.ancestor(_c2) and compare it to ca, because there

    # can be multiple common ancestors, e.g. in case of bidmerge.  Because our

    # caller may not know if the revision passed in lieu of the CA is a genuine

    # common ancestor or not without explicitly checking it, it's better to

    # determine that here.

    #

    # base.isancestorof(wc) is False, work around that

    _c1 = c1.p1() if c1.rev() is None else c1

    _c2 = c2.p1() if c2.rev() is None else c2

    # an endpoint is "dirty" if it isn't a descendant of the merge base

    # if we have a dirty endpoint, we need to trigger graft logic, and also

    # keep track of which endpoint is dirty

    dirtyc1 = not base.isancestorof(_c1)

    dirtyc2 = not base.isancestorof(_c2)

    graft = dirtyc1 or dirtyc2

    tca = base

    if graft:

        tca = _c1.ancestor(_c2)

    limit = copies._findlimit(repo, c1.rev(), c2.rev())

    if limit is None:

        # no common ancestor, no copies

        return {}, {}, {}, {}, {}

    repo.ui.debug("  searching for copies back to rev %d\n" % limit)

    m1 = c1.manifest()

    m2 = c2.manifest()

    mb = base.manifest()

    # gather data from _checkcopies:

    # - diverge = record all diverges in this dict

    # - copy = record all non-divergent copies in this dict

    # - fullcopy = record all copies in this dict

    # - incomplete = record non-divergent partial copies here

    # - incompletediverge = record divergent partial copies here

    diverge = {} # divergence data is shared

    incompletediverge = {}

    data1 = {'copy': {},

             'fullcopy': {},

             'incomplete': {},

             'diverge': diverge,

             'incompletediverge': incompletediverge,

            }

    data2 = {'copy': {},

             'fullcopy': {},

             'incomplete': {},

             'diverge': diverge,

             'incompletediverge': incompletediverge,

            }

    # find interesting file sets from manifests

    addedinm1 = m1.filesnotin(mb)

    addedinm2 = m2.filesnotin(mb)

    bothnew = sorted(addedinm1 & addedinm2)

    if tca == base:

        # unmatched file from base

        u1r, u2r = copies._computenonoverlap(repo, c1, c2, addedinm1, addedinm2)

        u1u, u2u = u1r, u2r

    else:

        # unmatched file from base (DAG rotation in the graft case)

        u1r, u2r = copies._computenonoverlap(repo, c1, c2, addedinm1, addedinm2,

                                             baselabel='base')

        # unmatched file from topological common ancestors (no DAG rotation)

        # need to recompute this for directory move handling when grafting

        mta = tca.manifest()

        u1u, u2u = copies._computenonoverlap(repo, c1, c2, m1.filesnotin(mta),

                                             m2.filesnotin(mta),

                                             baselabel='topological common ancestor')

    for f in u1u:

        copies._checkcopies(c1, c2, f, base, tca, dirtyc1, limit, data1)

    for f in u2u:

        copies._checkcopies(c2, c1, f, base, tca, dirtyc2, limit, data2)

    copy = dict(data1['copy'])

    copy.update(data2['copy'])

    fullcopy = dict(data1['fullcopy'])

    fullcopy.update(data2['fullcopy'])

    if dirtyc1:

        copies._combinecopies(data2['incomplete'], data1['incomplete'], copy, diverge,

                              incompletediverge)

    else:

        copies._combinecopies(data1['incomplete'], data2['incomplete'], copy, diverge,

                              incompletediverge)

    renamedelete = {}

    renamedeleteset = set()

    divergeset = set()

    for of, fl in list(diverge.items()):

        if len(fl) == 1 or of in c1 or of in c2:

            del diverge[of] # not actually divergent, or not a rename

            if of not in c1 and of not in c2:

                # renamed on one side, deleted on the other side, but filter

                # out files that have been renamed and then deleted

                renamedelete[of] = [f for f in fl if f in c1 or f in c2]

                renamedeleteset.update(fl) # reverse map for below

        else:

            divergeset.update(fl) # reverse map for below

    if bothnew:

        repo.ui.debug("  unmatched files new in both:\n   %s\n"

                      % "\n   ".join(bothnew))

    bothdiverge = {}

    bothincompletediverge = {}

    remainder = {}

    both1 = {'copy': {},

             'fullcopy': {},

             'incomplete': {},

             'diverge': bothdiverge,

             'incompletediverge': bothincompletediverge

            }

    both2 = {'copy': {},

             'fullcopy': {},

             'incomplete': {},

             'diverge': bothdiverge,

             'incompletediverge': bothincompletediverge

            }

    for f in bothnew:

        copies._checkcopies(c1, c2, f, base, tca, dirtyc1, limit, both1)

        copies._checkcopies(c2, c1, f, base, tca, dirtyc2, limit, both2)

    if dirtyc1 and dirtyc2:

        pass

    elif dirtyc1:

        # incomplete copies may only be found on the "dirty" side for bothnew

        assert not both2['incomplete']

        remainder = copies._combinecopies({}, both1['incomplete'], copy, bothdiverge,

                                          bothincompletediverge)

    elif dirtyc2:

        assert not both1['incomplete']

        remainder = copies._combinecopies({}, both2['incomplete'], copy, bothdiverge,

                                          bothincompletediverge)

    else:

        # incomplete copies and divergences can't happen outside grafts

        assert not both1['incomplete']

        assert not both2['incomplete']

        assert not bothincompletediverge

    for f in remainder:

        assert f not in bothdiverge

        ic = remainder[f]

        if ic[0] in (m1 if dirtyc1 else m2):

            # backed-out rename on one side, but watch out for deleted files

            bothdiverge[f] = ic

    for of, fl in bothdiverge.items():

        if len(fl) == 2 and fl[0] == fl[1]:

            copy[fl[0]] = of # not actually divergent, just matching renames

    if fullcopy and repo.ui.debugflag:

        repo.ui.debug("  all copies found (* = to merge, ! = divergent, "

                      "% = renamed and deleted):\n")

        for f in sorted(fullcopy):

            note = ""

            if f in copy: