fix: remove emptied lineages from non_empty_histories in truncate

[MozirDmitriy]

[LargeSmtForest::truncate]

crypto/miden-crypto/src/merkle/smt/large_forest/mod.rs

Lines 245 to 260 in ff3a912

	/// Removes all tree versions in the forest that are older than the provided `version`, but
	/// always retains the latest tree in each lineage.
	pub fn truncate(&mut self, version: VersionId) {
	let mut newly_empty = Set::default();
	self.non_empty_histories.iter().for_each(|l| {
	if let Some(d) = self.lineage_data.get_mut(l)
	&& d.truncate(version)
	{
	newly_empty.insert(*l);
	}
	});
	self.non_empty_histories.extend(newly_empty);
	}
	}

collected lineages whose histories became empty into a newly_empty set, but then called self.non_empty_histories.extend(newly_empty) instead of removing them. Since these lineages were already in the set, extend was a no-op, and emptied lineages were never cleaned up — breaking the invariant that non_empty_histories only contains lineages with actual deltas.

Replaceed extend with a removal loop so emptied lineages are properly evicted from non_empty_histories after truncation.

[huitseeker]

Nice catch, it would be great to have a test that would have caught this bug :)

[MozirDmitriy]

Nice catch, it would be great to have a test that would have caught this bug :)

Added two tests
First test fails with old behaviour
Second - additional test, partially truncates a lineage (version < latest_version) so history still has entries. Asserts the lineage stays in non_empty_histories.

[huitseeker]

LGTM, this just needs a Changelog entry

[MozirDmitriy]

LGTM, this just needs a Changelog entry

Added

[huitseeker]

TYVM!