Reuse document indexes for collection policy checks

internal/engine/inheritance_collection.go

@@ -103,15 +103,19 @@ func mergeInheritanceCollectionPolicies(
 	for key, entry := range child.collections {
 		paths[key] = entry.destination.clone()
 	}
+	var lookup *documentLookup
+	if len(paths) != 0 {
+		lookup = buildDocumentLookup(parentValue, childValue)
+	}
 	var diagnostics []Diagnostic
 	for _, path := range paths {
 		relative, inside := relativeHistoryPath(parentRootPath, path)
 		var retained, incoming *document.Node
 		if inside {
 			if !replaced.contains(path, false) {
-				retained, _ = documentAtPath(parentValue, relative)
+				retained, _ = documentAtPathWithLookup(parentValue, relative, lookup)
 			}
-			incoming, _ = documentAtPath(childValue, relative)
+			incoming, _ = documentAtPathWithLookup(childValue, relative, lookup)
 		}
 		resolution, lower, _, active, issues := inheritanceCollectionResolution(path, parent, child, applicationPolicy, incoming)
 		if len(issues) != 0 {