Function change_union

atomic-cli/src/commands/clone/helpers.rs:445–456

The union of change hashes across a set of manifests. Changes are content-addressed and shared across views (a draft's log includes its inherited prefix), so the union is deduplicated: each hash appears once, at its first occurrence. Iterating manifests root→leaf therefore yields parents' changes before children's own suffixes.

(manifests: &[ViewManifest])

/// appears once, at its first occurrence. Iterating manifests root→leaf
/// therefore yields parents' changes before children's own suffixes.
pub fn change_union(manifests: &[ViewManifest]) -> Vec<Hash> {
    let mut seen: HashSet<Hash> = HashSet::new();
    let mut union = Vec::new();
    for manifest in manifests {
        for hash in &manifest.changes {
            if seen.insert(*hash) {
                union.push(*hash);
            }
        }
    }
    union
}

// Inventory Support Detection