comparison mercurial/copies.py @ 46036:8d54944eaeb0

copies: properly copies parent dictionary before updating it

This enforces the copy on write logic. Otherwise independant unrelated branches
could affected each other.

More testing of these case are coming, but I need that code landed to unlock
other performance work in parallel.

Differential Revision: https://phab.mercurial-scm.org/D9419

46035:6c960b708ac4

                # In case of conflict, parent 1 take precedence over parent 2.
                # This is an arbitrary choice made anew when implementing
                # changeset based copies. It was made without regards with
                # potential filelog related behavior.
                if parent == 1:
                    minor, major = othercopies, newcopies
                else:
                    minor, major = newcopies, othercopies
                copies = _merge_copies_dict(minor, major, isancestor, changes)
                all_copies[c] = copies

    final_copies = {}
    for dest, (tt, source) in all_copies[targetrev].items():

46036:8d54944eaeb0

                # In case of conflict, parent 1 take precedence over parent 2.
                # This is an arbitrary choice made anew when implementing
                # changeset based copies. It was made without regards with
                # potential filelog related behavior.
                if parent == 1:
                    if newcopies is copies:
                        newcopies = copies.copy()
                    minor, major = othercopies, newcopies
                else:
                    # we do not know if the other dict is a copy or not, so we
                    # need to blindly copy it. Future change should make this
                    # unnecessary.
                    minor, major = newcopies, othercopies.copy()
                copies = _merge_copies_dict(minor, major, isancestor, changes)
                all_copies[c] = copies

    final_copies = {}
    for dest, (tt, source) in all_copies[targetrev].items():