comparison mercurial/copies.py @ 42594:d013099c551b

copies: filter invalid copies only at end of pathcopies() (issue6163)

copies._filter() filters out copies whose source file does not exist
in the start commit or whose target file does not exist in the end
commit. We do that after chaining copies with dirstate copies or
backward renames from another branch. We also do at the end of the
changeset-centric copy tracing. The filtering means that we will
remove copies to/from files that did not exist in some intermediate
commit. That is inconsistent with what we do if a file has been
deleted and then re-added (we allow updating across that).

Copying the two first examples from issue6163:

  @  4 'rename x to y'
  |
  o  3 'add x again'
  |
  o  2 'remove x'
  |
  | o  1 'modify x'
  |/
  o  0 'add x'

  @  4 'rename x to y'
  |
  o  3 'add x again'
  |
  | o  2 'modify x'
  | |
  | o  1 'add x'
  |/
  o  0 'base'

When doing `hg rebase -r 1 -d 4` in the first case, it succeeds, but
`hg rebase -r 2 -d 4` in the second case does not. That's because we
chain and filter via commit 0, which does not have file 'x' in the
second case. IMO, that's clearly inconsistent. So this patch removes
the filtering step so it only happens at the end. If a file was
temporarily removed, whether via a merge base or not, it will now
still be considered the same file. That fixes issue6163 for the
changeset-centric case.

Differential Revision: https://phab.mercurial-scm.org/D6603

42593:11ceb1b8fd74

                if dst not in copies:
                    # If it was copied on the p1 side, leave it as copied from
                    # that side, even if it was also copied on the p2 side.
                    copies[dst] = copies2[dst]
        if r == b.rev():
            _filter(a, b, copies)
            return copies
        for i, c in enumerate(children[r]):
            childctx = repo[c]
            if r == childctx.p1().rev():
                parent = 1

    # check for working copy
    if b.rev() is None:
        cm = _committedforwardcopies(a, b.p1(), match)
        # combine copies from dirstate if necessary
        copies = _chain(cm, _dirstatecopies(b._repo, match))
        _filter(a, b, copies)
    else:
        copies  = _committedforwardcopies(a, b, match)
    return copies

def _backwardrenames(a, b, match):

    else:
        if debug:
            repo.ui.debug('debug.copies: search mode: combined\n')
        copies = _chain(_backwardrenames(x, a, match=match),
                        _forwardcopies(a, y, match=match))
        _filter(x, y, copies)
    return copies

def mergecopies(repo, c1, c2, base):
    """
    Finds moves and copies between context c1 and c2 that are relevant for

42594:d013099c551b

                if dst not in copies:
                    # If it was copied on the p1 side, leave it as copied from
                    # that side, even if it was also copied on the p2 side.
                    copies[dst] = copies2[dst]
        if r == b.rev():
            return copies
        for i, c in enumerate(children[r]):
            childctx = repo[c]
            if r == childctx.p1().rev():
                parent = 1

    # check for working copy
    if b.rev() is None:
        cm = _committedforwardcopies(a, b.p1(), match)
        # combine copies from dirstate if necessary
        copies = _chain(cm, _dirstatecopies(b._repo, match))
    else:
        copies  = _committedforwardcopies(a, b, match)
    return copies

def _backwardrenames(a, b, match):

    else:
        if debug:
            repo.ui.debug('debug.copies: search mode: combined\n')
        copies = _chain(_backwardrenames(x, a, match=match),
                        _forwardcopies(a, y, match=match))
    _filter(x, y, copies)
    return copies

def mergecopies(repo, c1, c2, base):
    """
    Finds moves and copies between context c1 and c2 that are relevant for