Separate "filtered" attribute for ERROR dispatch

Closes gh-22989

Author: rstoyanchev

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 package org.springframework.web.filter;
 
 import java.io.IOException;
+import javax.servlet.DispatcherType;
 import javax.servlet.FilterChain;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
@@ -93,6 +94,7 @@ public final void doFilter(ServletRequest request, ServletResponse response, Fil
 		HttpServletResponse httpResponse = (HttpServletResponse) response;
 
 		String alreadyFilteredAttributeName = getAlreadyFilteredAttributeName();
+		alreadyFilteredAttributeName = updateForErrorDispatch(alreadyFilteredAttributeName, request);
 		boolean hasAlreadyFilteredAttribute = request.getAttribute(alreadyFilteredAttributeName) != null;
 
 		if (hasAlreadyFilteredAttribute || skipDispatch(httpRequest) || shouldNotFilter(httpRequest)) {
@@ -165,6 +167,21 @@ protected String getAlreadyFilteredAttributeName() {
 		return name + ALREADY_FILTERED_SUFFIX;
 	}
 
+	private String updateForErrorDispatch(String alreadyFilteredAttributeName, ServletRequest request) {
+
+		// Jetty does ERROR dispatch within sendError, so request attribute is still present
+		// Use a separate attribute for ERROR dispatches
+
+		if (DispatcherType.ERROR.equals(request.getDispatcherType()) && !shouldNotFilterErrorDispatch() &&
+				request.getAttribute(alreadyFilteredAttributeName) != null) {
+
+			return alreadyFilteredAttributeName + ".ERROR";
+		}
+
+
+		return alreadyFilteredAttributeName;
+	}
+
 	/**
 	 * Can be overridden in subclasses for custom filtering control,
 	 * returning {@code true} to avoid filtering of the given request.