21047: Fixes crashes with self-referential nodes used in certain opco…

…des. Also reclaims memory from intersect/union/mix operations. (#198)

src/Amalgam/evaluablenode/EvaluableNodeManagement.h

@@ -394,27 +394,24 @@ class EvaluableNodeManager
 	//if candidate is not unique, then it allocates and returns a new node
 	inline EvaluableNodeReference ReuseOrAllocNode(EvaluableNodeReference candidate, EvaluableNodeType type)
 	{
-		if(candidate.unique && candidate != nullptr)
+		//if not cyclic, can attempt to free all child nodes
+		//if cyclic, don't try, in case a child node points back to candidate
+		if(candidate.unique && candidate != nullptr && !candidate->GetNeedCycleCheck())
 		{
-			//if not cyclic, can attempt to free all child nodes
-			//if cyclic, don't try, in case a child node points back to candidate
-			if(!candidate->GetNeedCycleCheck())
+			if(candidate->IsAssociativeArray())
 			{
-				if(candidate->IsAssociativeArray())
+				for(auto &[_, e] : candidate->GetMappedChildNodesReference())
 				{
-					for(auto &[_, e] : candidate->GetMappedChildNodesReference())
-					{
-						if(e != nullptr)
-							FreeNodeTreeRecurse(e);
-					}
+					if(e != nullptr)
+						FreeNodeTreeRecurse(e);
 				}
-				else if(!candidate->IsImmediate())
+			}
+			else if(!candidate->IsImmediate())
+			{
+				for(auto &e : candidate->GetOrderedChildNodesReference())
 				{
-					for(auto &e : candidate->GetOrderedChildNodesReference())
-					{
-						if(e != nullptr)
-							FreeNodeTreeRecurse(e);
-					}
+					if(e != nullptr)
+						FreeNodeTreeRecurse(e);
 				}
 			}
 
@@ -625,7 +622,7 @@ class EvaluableNodeManager
 	//attempts to free the node reference
 	__forceinline void FreeNodeIfPossible(EvaluableNodeReference &enr)
 	{
-		if(enr.unique && !enr.IsImmediateValue())
+		if(enr.unique && !enr.IsImmediateValue() && !enr->GetNeedCycleCheck())
 			FreeNode(enr);
 	}
 

src/Amalgam/interpreter/InterpreterOpcodesCodeMixing.cpp

@@ -156,11 +156,13 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_INTERSECT(EvaluableNode *e
 	auto node_stack = CreateInterpreterNodeStackStateSaver(n1);
 
 	auto n2 = InterpretNodeForImmediateUse(ocn[1]);
-	node_stack.PushEvaluableNode(n2);
 
 	EvaluableNode *result = EvaluableNodeTreeManipulation::IntersectTrees(evaluableNodeManager, n1, n2);
-
 	EvaluableNodeManager::UpdateFlagsForNodeTree(result);
+
+	evaluableNodeManager->FreeNodeTreeIfPossible(n1);
+	evaluableNodeManager->FreeNodeTreeIfPossible(n2);
+
 	return EvaluableNodeReference(result, true);
 }
 
@@ -175,11 +177,13 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_UNION(EvaluableNode *en, b
 	auto node_stack = CreateInterpreterNodeStackStateSaver(n1);
 
 	auto n2 = InterpretNodeForImmediateUse(ocn[1]);
-	node_stack.PushEvaluableNode(n2);
 
 	EvaluableNode *result = EvaluableNodeTreeManipulation::UnionTrees(evaluableNodeManager, n1, n2);
-
 	EvaluableNodeManager::UpdateFlagsForNodeTree(result);
+
+	evaluableNodeManager->FreeNodeTreeIfPossible(n1);
+	evaluableNodeManager->FreeNodeTreeIfPossible(n2);
+
 	return EvaluableNodeReference(result, true);
 }
 
@@ -197,8 +201,8 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_DIFFERENCE(EvaluableNode *
 	node_stack.PushEvaluableNode(n2);
 
 	EvaluableNode *result = EvaluableNodeTreeDifference::DifferenceTrees(evaluableNodeManager, n1, n2);
-
 	EvaluableNodeManager::UpdateFlagsForNodeTree(result);
+
 	return EvaluableNodeReference(result, (n1.unique && n2.unique));
 }
 
@@ -248,12 +252,14 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_MIX(EvaluableNode *en, boo
 	auto node_stack = CreateInterpreterNodeStackStateSaver(n1);
 
 	auto n2 = InterpretNodeForImmediateUse(ocn[1]);
-	node_stack.PushEvaluableNode(n2);
 
 	EvaluableNode *result = EvaluableNodeTreeManipulation::MixTrees(randomStream.CreateOtherStreamViaRand(),
 		evaluableNodeManager, n1, n2, blend1, blend2, similar_mix_chance);
-
 	EvaluableNodeManager::UpdateFlagsForNodeTree(result);
+
+	evaluableNodeManager->FreeNodeTreeIfPossible(n1);
+	evaluableNodeManager->FreeNodeTreeIfPossible(n2);
+
 	return EvaluableNodeReference(result, true);
 }
 
@@ -298,8 +304,8 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_MIX_LABELS(EvaluableNode *
 	node_stack.PushEvaluableNode(n2);
 
 	EvaluableNode *result = EvaluableNodeTreeManipulation::MixTreesByCommonLabels(this, evaluableNodeManager, n1, n2, randomStream, blend1, blend2);
-
 	EvaluableNodeManager::UpdateFlagsForNodeTree(result);
+
 	return EvaluableNodeReference(result, (n1.unique && n2.unique));
 }