fix dag.getPreviousNodes miss upstream node (#13255)

dolphinscheduler-master/src/main/java/org/apache/dolphinscheduler/server/master/runner/WorkflowExecuteRunnable.java

@@ -153,6 +153,12 @@ public class WorkflowExecuteRunnable implements Callable<WorkflowSubmitStatue> {
 
     private DAG<String, TaskNode, TaskNodeRelation> dag;
 
+    /**
+     * full task node map, key is task node id, value is task node
+     * # TODO: This field can be removed later if the dag is complete
+     */
+    private Map<Long, TaskNode> taskNodesMap;
+
     /**
      * unique key of workflow
      */
@@ -809,6 +815,8 @@ public class WorkflowExecuteRunnable implements Callable<WorkflowSubmitStatue> {
             }
         });
 
+        taskNodesMap = taskNodeList.stream().collect(Collectors.toMap(TaskNode::getCode, taskNode -> taskNode));
+
         // generate process to get DAG info
         List<String> recoveryNodeCodeList = getRecoveryNodeCodeList(recoverNodeList);
         List<String> startNodeNameList = parseStartNodeName(processInstance.getCommandParam());
@@ -1857,8 +1865,10 @@ public class WorkflowExecuteRunnable implements Callable<WorkflowSubmitStatue> {
             // init varPool only this task is the first time running
             if (task.isFirstRun()) {
                 // get pre task ,get all the task varPool to this task
-                Set<String> preTask = dag.getPreviousNodes(Long.toString(task.getTaskCode()));
-                getPreVarPool(task, preTask);
+                // Do not use dag.getPreviousNodes because of the dag may be miss the upstream node
+                String preTasks = taskNodesMap.get(task.getTaskCode()).getPreTasks();
+                Set<String> preTaskList = new HashSet<>(JSONUtils.toList(preTasks, String.class));
+                getPreVarPool(task, preTaskList);
             }
             DependResult dependResult = getDependResultForTask(task);
             if (DependResult.SUCCESS == dependResult) {