ForwardedHeaderFilter requestURI preserve encoding

Previously ForwardedHeaderFilter would override the requestURI with a URL decoded value. This would cause
problems when using a URL encoded requestURI since downstream Filters would not see the URL encoded
value as they should.

This commit resolves this issue by ensuring that the requestURI is properly encoded.

Issues SPR-15422

spring-web/src/main/java/org/springframework/web/filter/ForwardedHeaderFilter.java

@@ -69,7 +69,12 @@ public class ForwardedHeaderFilter extends OncePerRequestFilter {
 	}
 
 
-	private final UrlPathHelper pathHelper = new UrlPathHelper();
+	private final UrlPathHelper pathHelper;
+
+	public ForwardedHeaderFilter() {
+		this.pathHelper = new UrlPathHelper();
+		this.pathHelper.setUrlDecode(false);
+	}
 
 
 	@Override

spring-web/src/test/java/org/springframework/web/filter/ForwardedHeaderFilterTests.java

@@ -106,6 +106,18 @@ public class ForwardedHeaderFilterTests {
 		assertEquals("", actual.getContextPath());
 		assertEquals("/path/", actual.getRequestURI());
 	}
+
+	@Test
+	public void requestUriPreserveEncoding() throws Exception {
+		this.request.setContextPath("/app");
+		this.request.setRequestURI("/app/path%20with%20spaces/");
+		HttpServletRequest actual = filterAndGetWrappedRequest();
+
+		assertEquals("/app", actual.getContextPath());
+		assertEquals("/app/path%20with%20spaces/", actual.getRequestURI());
+		assertEquals("http://localhost/app/path%20with%20spaces/", actual.getRequestURL().toString());
+	}
+
 	@Test
 	public void requestUriEqualsContextPath() throws Exception {
 		this.request.addHeader(X_FORWARDED_PREFIX, "/");