Fix ForwardedHeaderFilter with non-empty contextPath

Issue: SPR-15088

Author: Rob Winch

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

@@ -262,7 +262,7 @@ public void sendRedirect(String location) throws IOException {
 			// Relative to Servlet container root or to current request
 			String path;
 			if (location.startsWith(FOLDER_SEPARATOR)) {
-				path = this.request.getContextPath() + location;
+				path = location;
 			}
 			else {
 				path = StringUtils.applyRelativePath(this.request.getRequestURI(), location);

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

@@ -240,33 +240,10 @@ public void sendRedirectWithContextPath() throws Exception {
 		this.request.addHeader(X_FORWARDED_PORT, "443");
 		this.request.setContextPath("/context");
 
-		String redirectedUrl = sendRedirect("/foo/bar");
+		String redirectedUrl = sendRedirect("/context/foo/bar");
 		assertEquals("https://example.com/context/foo/bar", redirectedUrl);
 	}
 
-	@Test
-	public void sendRedirectWithXForwardedPrefix() throws Exception {
-		this.request.addHeader(X_FORWARDED_PROTO, "https");
-		this.request.addHeader(X_FORWARDED_HOST, "example.com");
-		this.request.addHeader(X_FORWARDED_PORT, "443");
-		this.request.addHeader(X_FORWARDED_PREFIX, "/prefix");
-
-		String redirectedUrl = sendRedirect("/foo/bar");
-		assertEquals("https://example.com/prefix/foo/bar", redirectedUrl);
-	}
-
-	@Test
-	public void sendRedirectWithXForwardedPrefixAndContextPath() throws Exception {
-		this.request.addHeader(X_FORWARDED_PROTO, "https");
-		this.request.addHeader(X_FORWARDED_HOST, "example.com");
-		this.request.addHeader(X_FORWARDED_PORT, "443");
-		this.request.addHeader(X_FORWARDED_PREFIX, "/prefix");
-		this.request.setContextPath("/context");
-
-		String redirectedUrl = sendRedirect("/foo/bar");
-		assertEquals("https://example.com/prefix/foo/bar", redirectedUrl);
-	}
-
 	@Test
 	public void sendRedirectWithRelativePath() throws Exception {
 		this.request.addHeader(X_FORWARDED_PROTO, "https");