fixing memory leaks

src/execution_plan/execution_plan.c

@@ -639,7 +639,6 @@ static void _ExecutionPlanSegment_ConvertClause(GraphContext *gc, AST *ast, Exec
 void ExecutionPlan_PopulateExecutionPlan(ExecutionPlan *plan) {
 	AST *ast = QueryCtx_GetAST();
 	GraphContext *gc = QueryCtx_GetGraphCtx();
-	plan->ast_segment = ast;
 
 	// Initialize the plan's record mapping if necessary.
 	// It will already be set if this ExecutionPlan has been created to populate a single stream.
@@ -793,7 +792,7 @@ ExecutionPlan *NewExecutionPlan(void) {
 		// Construct a new ExecutionPlanSegment.
 		ExecutionPlan *segment = ExecutionPlan_NewEmptyExecutionPlan();
 		ExecutionPlan_PopulateExecutionPlan(segment);
-
+		segment->ast_segment = ast_segment;
 		segments[i] = segment;
 		start_offset = end_offset;
 	}
@@ -1044,6 +1043,7 @@ void ExecutionPlan_Free(ExecutionPlan *plan) {
 	QueryGraph_Free(plan->query_graph);
 	if(plan->record_map) raxFree(plan->record_map);
 	if(plan->record_pool) ObjectPool_Free(plan->record_pool);
+	if(plan->ast_segment) AST_Free(plan->ast_segment);
 	rm_free(plan);
 }