Recognize wildcards in media types with a suffix

The "includes" and "isCompatibleWith" methods of MediaType take into
account media types with suffices (e.g. application/soap+xml) including
wildcards with suffices (e.g. application/*+xml). However before this
change, the isWildcardSubtype() method returned true only for subtype
"*". Now a media type such as application/*+xml is also recognized as
having a wildcard subtype.

Issue: SPR-9841

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/RequestResponseBodyMethodProcessorMockTests.java

@@ -279,6 +279,28 @@ public class RequestResponseBodyMethodProcessorMockTests {
 		processor.handleReturnValue("Foo", returnTypeStringProduces, mavContainer, webRequest);
 	}
 
+	// SPR-9841
+
+	@Test
+	public void handleReturnValueMediaTypeSuffix() throws Exception {
+		String body = "Foo";
+		MediaType accepted = MediaType.APPLICATION_XHTML_XML;
+		List<MediaType> supported = Collections.singletonList(MediaType.valueOf("application/*+xml"));
+
+		servletRequest.addHeader("Accept", accepted);
+
+		expect(messageConverter.canWrite(String.class, null)).andReturn(true);
+		expect(messageConverter.getSupportedMediaTypes()).andReturn(supported);
+		expect(messageConverter.canWrite(String.class, accepted)).andReturn(true);
+		messageConverter.write(eq(body), eq(accepted), isA(HttpOutputMessage.class));
+		replay(messageConverter);
+
+		processor.handleReturnValue(body, returnTypeStringProduces, mavContainer, webRequest);
+
+		assertTrue(mavContainer.isRequestHandled());
+		verify(messageConverter);
+	}
+
 	// SPR-9160
 
 	@Test
@@ -308,6 +330,7 @@ public class RequestResponseBodyMethodProcessorMockTests {
 		assertEquals("Foo", servletResponse.getContentAsString());
 	}
 
+
 	@ResponseBody
 	public String handle1(@RequestBody String s, int i) {
 		return s;