comparison mercurial/dirstatemap.py @ 50097:ca9d65d69c27 stable

dirstate-v2: complain early on docket name collision

The alternative is that the dirstate gets deleted so the
corruption persists and is hard to investigate.

This happened to me in tests, where the dirstate names
are taken from file, since the file got reverted.
I expect this can also happen in prod with non-trivial
probability (1/4 billion).

50092:010a1e73f69e

    def write_v2_no_append(self, tr, st, meta, packed):
        old_docket = self.docket
        new_docket = docketmod.DirstateDocket.with_new_uuid(
            self.parents(), len(packed), meta
        )
        data_filename = new_docket.data_filename()
        self._opener.write(data_filename, packed)
        # Write the new docket after the new data file has been
        # written. Because `st` was opened with `atomictemp=True`,
        # the actual `.hg/dirstate` file is only affected on close.

50097:ca9d65d69c27

    def write_v2_no_append(self, tr, st, meta, packed):
        old_docket = self.docket
        new_docket = docketmod.DirstateDocket.with_new_uuid(
            self.parents(), len(packed), meta
        )
        if old_docket.uuid == new_docket.uuid:
            raise error.ProgrammingError(b'dirstate docket name collision')
        data_filename = new_docket.data_filename()
        self._opener.write(data_filename, packed)
        # Write the new docket after the new data file has been
        # written. Because `st` was opened with `atomictemp=True`,
        # the actual `.hg/dirstate` file is only affected on close.