Return 415 on bad request body content-type

Issue: SPR-10982

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/AbstractMessageConverterMethodArgumentResolver.java

@@ -33,6 +33,7 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.core.GenericTypeResolver;
 import org.springframework.core.MethodParameter;
 import org.springframework.http.HttpInputMessage;
+import org.springframework.http.InvalidMediaTypeException;
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.GenericHttpMessageConverter;
 import org.springframework.http.converter.HttpMessageConverter;
@@ -115,10 +116,17 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 	protected <T> Object readWithMessageConverters(HttpInputMessage inputMessage,
 			MethodParameter methodParam, Type targetType) throws IOException, HttpMediaTypeNotSupportedException {
 
-				MediaType contentType = inputMessage.getHeaders().getContentType();
-				if (contentType == null) {
-					contentType = MediaType.APPLICATION_OCTET_STREAM;
-				}
+		MediaType contentType;
+		try {
+			contentType = inputMessage.getHeaders().getContentType();
+		}
+		catch (InvalidMediaTypeException ex) {
+			throw new HttpMediaTypeNotSupportedException(ex.getMessage());
+		}
+
+		if (contentType == null) {
+			contentType = MediaType.APPLICATION_OCTET_STREAM;
+		}
 
 				Class<?> contextClass = methodParam.getDeclaringClass();
 				Map<TypeVariable, Type> map = GenericTypeResolver.getTypeVariableMap(contextClass);

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

@@ -187,6 +187,12 @@ public class RequestResponseBodyMethodProcessorMockTests {
 		}
 	}
 
+	@Test(expected = HttpMediaTypeNotSupportedException.class)
+	public void resolveArgumentInvalidContentType() throws Exception {
+		this.servletRequest.setContentType("bad");
+		processor.resolveArgument(paramRequestBodyString, mavContainer, webRequest, null);
+	}
+
 	@Test
 	public void resolveArgumentNotRequiredNoContent() throws Exception {
 		servletRequest.setContent(null);