more code cleanup

Author: hmottestad

core/model/src/main/java/org/eclipse/rdf4j/model/impl/AbstractMemoryOverflowModel.java

@@ -235,13 +235,21 @@ public boolean isEmpty() {
 	@Override
 	public boolean add(Resource subj, IRI pred, Value obj, Resource... contexts) {
 		checkMemoryOverflow();
-		return getDelegate().add(subj, pred, obj, contexts);
+		boolean add = getDelegate().add(subj, pred, obj, contexts);
+		if (add && memory instanceof DynamicModel) {
+			((DynamicModel) memory).maybeRegisterLargeStatementSetForReuse((DynamicModel) memory);
+		}
+		return add;
 	}
 
 	@Override
 	public boolean add(Statement st) {
 		checkMemoryOverflow();
-		return getDelegate().add(st);
+		boolean add = getDelegate().add(st);
+		if (add && memory instanceof DynamicModel) {
+			((DynamicModel) memory).maybeRegisterLargeStatementSetForReuse((DynamicModel) memory);
+		}
+		return add;
 	}
 
 	@Override
@@ -265,6 +273,10 @@ public boolean addAll(Collection<? extends Statement> c) {
 				buffer.clear();
 			}
 
+			if (ret && memory instanceof DynamicModel) {
+				((DynamicModel) memory).maybeRegisterLargeStatementSetForReuse((DynamicModel) memory);
+			}
+
 			return ret;
 
 		}
@@ -365,9 +377,6 @@ private static boolean matchesPattern(Statement statement, Resource subj, IRI pr
 	private Model getDelegate() {
 		var memory = this.memory;
 		if (memory != null) {
-			if (memory instanceof DynamicModel) {
-				((DynamicModel) memory).maybeRegisterLargeStatementSetForReuse((DynamicModel) memory);
-			}
 			return memory;
 		} else {
 			var disk = this.disk;

core/model/src/main/java/org/eclipse/rdf4j/model/impl/DynamicModel.java

@@ -664,10 +664,15 @@ private void readObject(ObjectInputStream objectInputStream) throws IOException,
 
 	private Set<Resource> initializeAddedContextsIfNeeded() {
 		if (addedContexts == null) {
-			addedContexts = statements.values()
-					.stream()
-					.map(Statement::getContext)
-					.collect(Collectors.toCollection(LinkedHashSet::new));
+			if (statements.isEmpty()) {
+
+				addedContexts = new LinkedHashSet<>(1);
+			} else {
+				addedContexts = statements.values()
+						.stream()
+						.map(Statement::getContext)
+						.collect(Collectors.toCollection(LinkedHashSet::new));
+			}
 		}
 		return addedContexts;
 	}