GH-2058 Ensure uniqueness of error infrustructure in the event destination has the same name (multiple binders)

Resolves #2058

spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binder/AbstractMessageChannelBinder.java

@@ -601,9 +601,11 @@ public abstract class AbstractMessageChannelBinder<C extends ConsumerProperties,
 				errorChannel.subscribe(bridge);
 			}
 		}
+		else {
+			((GenericApplicationContext) getApplicationContext()).registerBean(
+					errorChannelName, SubscribableChannel.class, () -> errorChannel);
+		}
 
-		((GenericApplicationContext) getApplicationContext()).registerBean(
-				errorChannelName, SubscribableChannel.class, () -> errorChannel);
 		MessageChannel defaultErrorChannel = null;
 		if (getApplicationContext()
 				.containsBean(IntegrationContextUtils.ERROR_CHANNEL_BEAN_NAME)) {
@@ -898,7 +900,7 @@ public abstract class AbstractMessageChannelBinder<C extends ConsumerProperties,
 	}
 
 	protected String getErrorBridgeName(ProducerDestination destination) {
-		return errorsBaseName(destination) + ".bridge";
+		return errorsBaseName(destination) + ".bridge" + destination.hashCode();
 	}
 
 	protected String errorsBaseName(ProducerDestination destination) {

spring-cloud-stream/src/test/java/org/springframework/cloud/stream/binder/test/TestChannelBinderTests.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2021-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.stream.binder.test;
+
+import java.lang.reflect.Method;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.WebApplicationType;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.cloud.stream.provisioning.ProducerDestination;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.util.ReflectionUtils;
+
+/**
+ *
+ * @author Oleg Zhurakousky
+ *
+ */
+public class TestChannelBinderTests {
+
+	@Test
+	public void test() throws Exception {
+		// nothing to assert. no failure on this test signifies success
+		try (ConfigurableApplicationContext context = new SpringApplicationBuilder(
+				TestChannelBinderConfiguration.getCompleteConfiguration(SampleConfiguration.class))
+						.web(WebApplicationType.NONE).run("--spring.jmx.enabled=false",
+								"--spring.cloud.stream.bindings.function-in-0.destination=input")) {
+			TestChannelBinder binder = context.getBean(TestChannelBinder.class);
+			Method registerErrorInfrastructure = ReflectionUtils
+					.findMethod(TestChannelBinder.class, "registerErrorInfrastructure", ProducerDestination.class);
+			registerErrorInfrastructure.setAccessible(true);
+			ProducerDestination destination = new ProducerDestination() {
+				@Override
+				public String getNameForPartition(int partition) {
+					return "sample";
+				}
+
+				@Override
+				public String getName() {
+					return "sample";
+				}
+			};
+			registerErrorInfrastructure.invoke(binder, destination);
+			destination = new ProducerDestination() {
+				@Override
+				public String getNameForPartition(int partition) {
+					return "sample";
+				}
+
+				@Override
+				public String getName() {
+					return "sample";
+				}
+			};
+			registerErrorInfrastructure.invoke(binder, destination);
+		}
+	}
+
+	@EnableAutoConfiguration
+	public static class SampleConfiguration {
+
+	}
+}