From d44feadc79dabde4cf37b14ecc47a85efe1b907c Mon Sep 17 00:00:00 2001
From: Alexander Shaklein <cheester.x3@gmail.com>
Date: Sat, 4 Jul 2020 22:58:49 +0300
Subject: [PATCH] GH-3324. fix NPE in StdIntFlowContext

Fixes https://github.com/spring-projects/spring-integration/issues/3324

The `StandardIntegrationFlowContext.remove()` has a possible NPE

**Cherry-pick to 5.3.x & 5.2.x**

(cherry picked from commit 7424cb215c3ea9a6a408992d50461973698c5c98)
---
 .../dsl/context/StandardIntegrationFlowContext.java          | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/spring-integration-core/src/main/java/org/springframework/integration/dsl/context/StandardIntegrationFlowContext.java b/spring-integration-core/src/main/java/org/springframework/integration/dsl/context/StandardIntegrationFlowContext.java
index 3ba73336a6..2200ee03b5 100644
--- a/spring-integration-core/src/main/java/org/springframework/integration/dsl/context/StandardIntegrationFlowContext.java
+++ b/spring-integration-core/src/main/java/org/springframework/integration/dsl/context/StandardIntegrationFlowContext.java
@@ -44,6 +44,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Artem Bilan
  * @author Gary Russell
+ * @author Alexander Shaklein
  *
  * @since 5.1
  *
@@ -177,8 +178,8 @@ public final class StandardIntegrationFlowContext implements IntegrationFlowCont
 	 */
 	@Override
 	public void remove(String flowId) {
-		if (this.registry.containsKey(flowId)) {
-			IntegrationFlowRegistration flowRegistration = this.registry.remove(flowId);
+		final IntegrationFlowRegistration flowRegistration = this.registry.remove(flowId);
+		if (flowRegistration != null) {
 			flowRegistration.stop();
 
 			removeDependantBeans(flowId);