rust: remove comment about error handling of AncestorsIterator
To be align with 443eb4bc41af "rust: propagate error of index_get_parents()
properly."
Spotted by Georges Racinet.
--- a/rust/hg-core/src/ancestors.rs Mon Dec 10 20:01:07 2018 +0000
+++ b/rust/hg-core/src/ancestors.rs Tue Dec 11 22:23:39 2018 +0900
@@ -105,18 +105,6 @@
/// (case where p1 == rev-1), because it amounts to update the first element
/// of the heap without sifting, which Rust's BinaryHeap doesn't let us do.
/// - we save a few pushes by comparing with `stoprev` before pushing
-///
-/// Error treatment:
-/// We swallow the possible GraphError of conditionally_push_parents() to
-/// respect the Iterator trait in a simple manner: never emitting parents
-/// for the returned revision. We finds this good enough for now, because:
-///
-/// - there's a good chance that invalid revisionss are fed from the start,
-/// and `new()` doesn't swallow the error result.
-/// - this is probably what the Python implementation produces anyway, due
-/// to filtering at each step, and Python code is currently the only
-/// concrete caller we target, so we shouldn't need a finer error treatment
-/// for the time being.
impl<G: Graph> Iterator for AncestorsIterator<G> {
type Item = Result<Revision, GraphError>;