dirstate-cext: properly invalidate mtime and data in `set_untracked`
This was forgotten about in the initial implementation and was revealed while
adding the `dirstate-v2` variant of `test-issue660.t`. Neither the existing
Python implementation nor the upcoming Rust implementation suffer from this
bug since they respectively have `None` and `Option<T>` to represent the lack
of information.
Differential Revision: https://phab.mercurial-scm.org/D12414
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
end_of_line = lf
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true
end_of_line = lf
[*.t]
indent_size = 2
indent_style = space
trim_trailing_whitespace = false
end_of_line = lf