GH-611 Fix regression for expectedContentType

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/SimpleFunctionRegistry.java

@@ -735,23 +735,11 @@ public class SimpleFunctionRegistry implements FunctionRegistry, FunctionInspect
 			Message outputMessage = null;
 			if (value instanceof Message) {
 				MessageHeaders headers = ((Message) value).getHeaders();
-				Map<String, Object> headersMap = (Map<String, Object>) ReflectionUtils
-					.getField(this.headersField, headers);
-				headersMap.put("accept", acceptedContentType);
-				// Set the contentType header to the value of accept for "legacy" reasons. But, do not set the
-				// contentType header to the value of accept if it is a wildcard type, as this doesn't make sense.
-				// This also applies to the else branch below.
-				if (acceptedContentType.isConcrete() && !headersMap.containsKey(MessageHeaders.CONTENT_TYPE)) {
-					headersMap.put(MessageHeaders.CONTENT_TYPE, acceptedContentType);
-				}
+				Map<String, Object> headersMap = (Map<String, Object>) ReflectionUtils.getField(this.headersField, headers);
+				headersMap.putIfAbsent(MessageHeaders.CONTENT_TYPE, acceptedContentType);
 			}
 			else {
-				MessageBuilder<Object> builder = MessageBuilder.withPayload(value)
-					.setHeader("accept", acceptedContentType);
-				if (acceptedContentType.isConcrete()) {
-					builder.setHeader(MessageHeaders.CONTENT_TYPE, acceptedContentType);
-				}
-				value = builder.build();
+				value = MessageBuilder.withPayload(value).setHeader(MessageHeaders.CONTENT_TYPE, acceptedContentType).build();
 			}
 			if (enricher != null) {
 				value = enricher.apply((Message) value);

spring-cloud-function-context/src/test/java/org/springframework/cloud/function/context/catalog/BeanFactoryAwareFunctionRegistryTests.java

@@ -59,6 +59,7 @@ import org.springframework.messaging.support.MessageBuilder;
 import org.springframework.stereotype.Component;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.MimeType;
+import org.springframework.util.MimeTypeUtils;
 import org.springframework.util.ReflectionUtils;
 
 import static java.util.Collections.singletonList;
@@ -531,6 +532,13 @@ public class BeanFactoryAwareFunctionRegistryTests {
 		assertThat(result.block()).isEqualTo("hello");
 	}
 
+	@Test
+	public void testGH_611() {
+		FunctionCatalog catalog = this.configureCatalog(NegotiatingMessageConverterConfiguration.class);
+		Supplier<Message<Integer>> f = catalog.lookup("supplier", "text/*");
+		assertThat(f.get().getHeaders().get(MessageHeaders.CONTENT_TYPE)).isEqualTo(MimeTypeUtils.parseMimeType("text/*"));
+	}
+
 	@EnableAutoConfiguration
 	public static class PojoToMessageFunctionCompositionConfiguration {
 
@@ -595,6 +603,11 @@ public class BeanFactoryAwareFunctionRegistryTests {
 	@EnableAutoConfiguration
 	public static class NegotiatingMessageConverterConfiguration {
 
+		@Bean
+		public Supplier<Integer> supplier() {
+			return () -> 123;
+		}
+
 		@Bean
 		public Function<String, String> echo() {
 			return v -> v;
@@ -610,6 +623,11 @@ public class BeanFactoryAwareFunctionRegistryTests {
 			return new ConverterB();
 		}
 
+		@Bean
+		public MessageConverter messageConverterC() {
+			return new ConverterC();
+		}
+
 
 		public static class ConverterB extends ConverterA {
 			ConverterB() {
@@ -639,6 +657,34 @@ public class BeanFactoryAwareFunctionRegistryTests {
 			}
 		}
 
+		public static class ConverterC extends ConverterA {
+			ConverterC() {
+				super("text/*");
+			}
+
+			@Override
+			protected Object convertFromInternal(
+					Message<?> message, Class<?> targetClass, @Nullable Object conversionHint) {
+				return message.getPayload().toString();
+			}
+
+			@Override
+			public Object convertToInternal(Object rawPayload, MessageHeaders headers, Object conversionHint) {
+				return rawPayload;
+			}
+
+			@Override
+			protected boolean canConvertFrom(Message<?> message, @Nullable Class<?> targetClass) {
+				return supportsMimeType(message.getHeaders()) && Integer.class.isAssignableFrom(targetClass)
+						&& message.getPayload() instanceof Integer;
+			}
+
+			@Override
+			protected boolean canConvertTo(Object payload, @Nullable MessageHeaders headers) {
+				return payload instanceof Integer;
+			}
+		}
+
 		private static class ConverterA extends AbstractMessageConverter {
 
 			ConverterA() {