rust-pyo3: implementation of LazyAncestors There is a difference in the implementaion of `__contains__` between PyO3 and rust-cpython: if the specified signature in Rust code is for a precise type (e.g., `PyRevision`) rust-cpython would automatically convert the potential resulting `TypeError` into `Ok(false)`, whereas PyO3 let it bubble up. Hence we treat the case manually and add it to the common test. In Mercurial Python code, `None in` for a `LazyAncestors` object can really happens, namely in this lambda from `discover._postprocessobsolete`: ``` ispushed = lambda n: torev(n) in futurecommon ``` This lambda can get called with `n` such that `torev(n)` is `False` (seen in `test-bookmarks-push-pull.t`).

--- a/rust/hg-pyo3/src/convert_cpython.rs	Sat Dec 07 18:42:06 2024 +0100
+++ b/rust/hg-pyo3/src/convert_cpython.rs	Sat Dec 07 18:54:31 2024 +0100
@@ -222,7 +222,6 @@
 /// static reference. It is possible, depending on `T` that such a leak cannot
 /// occur in practice. We may later on define a marker trait for this,
 /// which will allow us to make declare this function to be safe.
-#[allow(dead_code)]
 pub(crate) unsafe fn py_leaked_borrow<'a, 'py: 'a, T>(
     py: &impl WithGIL<'py>,
     leaked: &'a cpython::UnsafePyLeaked<T>,