dirstate: Appease pytype test-check-pytype.t was failing since 98c0408324e6: File "/home/simon/projects/hg/mercurial/dirstatemap.py", line 572, in addfile: unsupported operand type(s) for &: 'size: None' and 'rangemask: int' [unsupported-operands] No attribute '__and__' on 'size: None' or '__rand__' on 'rangemask: int' File "/home/simon/projects/hg/mercurial/dirstatemap.py", line 573, in addfile: unsupported operand type(s) for &: 'mtime: None' and 'rangemask: int' [unsupported-operands] No attribute '__and__' on 'mtime: None' or '__rand__' on 'rangemask: int' `None` is the default value of the `size` and `mtime` parameters of the `addfile` method. However, the relevant lines are only used in a code path where those defaults are never used. These `size` and `mtime` are passed to `DirstateItem.new_normal` which (in the C implementation) calls `dirstate_item_new_normal` which uses: PyArg_ParseTuple(args, "iii", &mode, &size, &mtime) So `None` values would cause an exception to be raised anyway. The new `assert`s only move that exception earlier, and informs pytype that we expect `None` to never happen in this code path. Differential Revision: https://phab.mercurial-scm.org/D11500