Use original query string of forwarded request

Prior to this commit, the AbstractFlashMapManager has used the
originating URI but the query string of the forwarded request. That
resulted to FlashMap not being matched even when both originating
URI and query string matched the FlashMap attributes. The originating
query string is now used to match the forwarded request.

Issue: SPR-15505

spring-webmvc/src/main/java/org/springframework/web/servlet/support/AbstractFlashMapManager.java

@@ -167,13 +167,14 @@ public abstract class AbstractFlashMapManager implements FlashMapManager {
 	 */
 	protected boolean isFlashMapForRequest(FlashMap flashMap, HttpServletRequest request) {
 		String expectedPath = flashMap.getTargetRequestPath();
+		String requestUri = getUrlPathHelper().getOriginatingRequestUri(request);
 		if (expectedPath != null) {
-			String requestUri = getUrlPathHelper().getOriginatingRequestUri(request);
 			if (!requestUri.equals(expectedPath) && !requestUri.equals(expectedPath + "/")) {
 				return false;
 			}
 		}
-		UriComponents uriComponents = ServletUriComponentsBuilder.fromRequest(request).build();
+		String queryString = getUrlPathHelper().getOriginatingQueryString(request);
+		UriComponents uriComponents = ServletUriComponentsBuilder.fromUriString(requestUri).query(queryString).build();
 		MultiValueMap<String, String> actualParams = uriComponents.getQueryParams();
 		MultiValueMap<String, String> expectedParams = flashMap.getTargetRequestParams();
 		for (String expectedName : expectedParams.keySet()) {

spring-webmvc/src/test/java/org/springframework/web/servlet/support/FlashMapManagerTests.java

@@ -318,6 +318,26 @@ public class FlashMapManagerTests {
 		assertEquals("value", flashMap.get("key"));
 	}
 
+	// SPR-15505
+
+	@Test
+	public void retrieveAndUpdateMatchByOriginatingPathAndQueryString() {
+		FlashMap flashMap = new FlashMap();
+		flashMap.put("key", "value");
+		flashMap.setTargetRequestPath("/accounts");
+		flashMap.addTargetRequestParam("a", "b");
+
+		this.flashMapManager.setFlashMaps(Arrays.asList(flashMap));
+
+		this.request.setAttribute(WebUtils.FORWARD_REQUEST_URI_ATTRIBUTE, "/accounts");
+		this.request.setAttribute(WebUtils.FORWARD_QUERY_STRING_ATTRIBUTE, "a=b");
+		this.request.setRequestURI("/mvc/accounts");
+		this.request.setQueryString("x=y");
+		FlashMap inputFlashMap = this.flashMapManager.retrieveAndUpdate(this.request, this.response);
+
+		assertEquals(flashMap, inputFlashMap);
+		assertEquals("Input FlashMap should have been removed", 0, this.flashMapManager.getFlashMaps().size());
+	}
 
 	private static class TestFlashMapManager extends AbstractFlashMapManager {