SPR-8782 Raise helpful error when RedirectAttributes is used with old infrastructure classes.

org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/annotation/ServletAnnotationControllerTests.java

@@ -138,6 +138,7 @@ import org.springframework.web.servlet.handler.SimpleUrlHandlerMapping;
 import org.springframework.web.servlet.mvc.AbstractController;
 import org.springframework.web.servlet.mvc.multiaction.InternalPathMethodNameResolver;
 import org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping;
+import org.springframework.web.servlet.mvc.support.RedirectAttributes;
 import org.springframework.web.servlet.view.InternalResourceViewResolver;
 import org.springframework.web.util.NestedServletException;
 
@@ -1910,6 +1911,17 @@ public class ServletAnnotationControllerTests {
 		assertEquals("homeJson", response.getContentAsString());
 	}	
 
+	@Test
+	public void redirectAttribute() throws Exception {
+		initServlet(RedirectAttributesController.class);
+		try {
+			servlet.service(new MockHttpServletRequest("GET", "/"), new MockHttpServletResponse());
+		}
+		catch (NestedServletException ex) {
+			assertTrue(ex.getMessage().contains("not assignable from the actual model"));
+		}
+	}
+	
 
 	/*
 	 * Controllers
@@ -3207,4 +3219,12 @@ public class ServletAnnotationControllerTests {
 		}
 	}
 
+	@Controller
+	static class RedirectAttributesController {
+
+		@RequestMapping(value = "/")
+		public void handle(RedirectAttributes redirectAttrs) {
+		}
+	}
+	
 }

org.springframework.web/src/main/java/org/springframework/web/bind/annotation/support/HandlerMethodInvoker.java

@@ -34,7 +34,6 @@ import java.util.Set;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.core.BridgeMethodResolver;
@@ -313,8 +312,13 @@ public class HandlerMethodInvoker {
 					args[i] = resolveDefaultValue(defaultValue);
 				}
 				else {
-					Class paramType = methodParam.getParameterType();
+					Class<?> paramType = methodParam.getParameterType();
 					if (Model.class.isAssignableFrom(paramType) || Map.class.isAssignableFrom(paramType)) {
+						if (!paramType.isAssignableFrom(implicitModel.getClass())) {
+							throw new IllegalStateException("Argument [" + paramType.getSimpleName() + "] is of type " +
+									"Model or Map but is not assignable from the actual model. You may need to switch " +
+									"newer MVC infrastructure classes to use this argument.");
+						}
 						args[i] = implicitModel;
 					}
 					else if (SessionStatus.class.isAssignableFrom(paramType)) {