Explicitly set status on raw unwrapped response

The ErrorPageFilter wasn't setting the response status in the case that
there was an error page mapped to the current request (i.e. for all
autoconfigured apps). N.B. this only affects non-embedded apps.

Fixes gh-1320

spring-boot/src/main/java/org/springframework/boot/context/web/ErrorPageFilter.java

@@ -56,7 +56,7 @@ import org.springframework.web.filter.OncePerRequestFilter;
 @Component
 @Order(Ordered.HIGHEST_PRECEDENCE)
 class ErrorPageFilter extends AbstractConfigurableEmbeddedServletContainer implements
-Filter, NonEmbeddedServletContainerFactory {
+		Filter, NonEmbeddedServletContainerFactory {
 
 	private static Log logger = LogFactory.getLog(ErrorPageFilter.class);
 
@@ -129,6 +129,7 @@ Filter, NonEmbeddedServletContainerFactory {
 			response.sendError(status, message);
 			return;
 		}
+		response.setStatus(status);
 		setErrorAttributes(request, status, message);
 		request.getRequestDispatcher(errorPath).forward(request, response);
 	}

spring-boot/src/test/java/org/springframework/boot/context/web/ErrorPageFilterTests.java

@@ -63,6 +63,28 @@ public class ErrorPageFilterTests {
 		assertTrue(this.response.isCommitted());
 	}
 
+	@Test
+	public void unauthorizedWithErrorPath() throws Exception {
+		this.filter.addErrorPages(new ErrorPage("/error"));
+		this.chain = new MockFilterChain() {
+			@Override
+			public void doFilter(ServletRequest request, ServletResponse response)
+					throws IOException, ServletException {
+				((HttpServletResponse) response).sendError(401, "UNAUTHORIZED");
+				super.doFilter(request, response);
+			}
+		};
+		this.filter.doFilter(this.request, this.response, this.chain);
+		assertThat(this.chain.getRequest(), equalTo((ServletRequest) this.request));
+		HttpServletResponseWrapper wrapper = (HttpServletResponseWrapper) this.chain
+				.getResponse();
+		assertThat(wrapper.getResponse(), equalTo((ServletResponse) this.response));
+		assertTrue(this.response.isCommitted());
+		assertThat(wrapper.getStatus(), equalTo(401));
+		// The real response has to be 401 as well...
+		assertThat(this.response.getStatus(), equalTo(401));
+	}
+
 	@Test
 	public void responseCommitted() throws Exception {
 		this.filter.addErrorPages(new ErrorPage("/error"));