From 51134d9738681c3d35455a9c8818e45f766a5b4e Mon Sep 17 00:00:00 2001
From: Hendrik Muhs <hendrik.muhs@elastic.co>
Date: Mon, 20 Jan 2020 13:52:19 +0100
Subject: [PATCH] check custom meta data to avoid NPE (#51163)

check custom meta data to avoid NPE, fixes a problem introduced in #51072

fixes #51153
---
 .../action/TransportStopTransformAction.java   | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/action/TransportStopTransformAction.java b/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/action/TransportStopTransformAction.java
index ab7c001b6e30d..98c45e1118657 100644
--- a/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/action/TransportStopTransformAction.java
+++ b/x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/action/TransportStopTransformAction.java
@@ -141,14 +141,16 @@ static Tuple<Set<String>, Set<String>> findTasksWithoutConfig(ClusterState state
         Set<String> taskIds = new HashSet<>();
         Set<String> executorNodes = new HashSet<>();
 
-        Predicate<PersistentTask<?>> taskMatcher = Strings.isAllOrWildcard(new String[] { transformId }) ? t -> true : t -> {
-            TransformTaskParams transformParams = (TransformTaskParams) t.getParams();
-            return Regex.simpleMatch(transformId, transformParams.getId());
-        };
-
-        for (PersistentTasksCustomMetaData.PersistentTask<?> pTask : tasks.findTasks(TransformField.TASK_NAME, taskMatcher)) {
-            executorNodes.add(pTask.getExecutorNode());
-            taskIds.add(pTask.getId());
+        if (tasks != null) {
+            Predicate<PersistentTask<?>> taskMatcher = Strings.isAllOrWildcard(new String[] { transformId }) ? t -> true : t -> {
+                TransformTaskParams transformParams = (TransformTaskParams) t.getParams();
+                return Regex.simpleMatch(transformId, transformParams.getId());
+            };
+
+            for (PersistentTasksCustomMetaData.PersistentTask<?> pTask : tasks.findTasks(TransformField.TASK_NAME, taskMatcher)) {
+                executorNodes.add(pTask.getExecutorNode());
+                taskIds.add(pTask.getId());
+            }
         }
 
         return new Tuple<>(taskIds, executorNodes);