CommonsMultipartFile removes mixed separator paths from original filename

Issue: SPR-13662
(cherry picked from commit 5d9d88c)

spring-web/src/main/java/org/springframework/web/multipart/commons/CommonsMultipartFile.java

@@ -31,7 +31,7 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.web.multipart.MultipartFile;
 
 /**
- * MultipartFile implementation for Apache Commons FileUpload.
+ * {@link MultipartFile} implementation for Apache Commons FileUpload.
  *
  * @author Trevor D. Cook
  * @author Juergen Hoeller
@@ -78,12 +78,13 @@ public class CommonsMultipartFile implements MultipartFile, Serializable {
 			// Should never happen.
 			return "";
 		}
+
 		// Check for Unix-style path
-		int pos = filename.lastIndexOf("/");
-		if (pos == -1) {
-			// Check for Windows-style path
-			pos = filename.lastIndexOf("\\");
-		}
+		int unixSep = filename.lastIndexOf("/");
+		// Check for Windows-style path
+		int winSep = filename.lastIndexOf("\\");
+		// Cut off at latest possible point
+		int pos = (winSep > unixSep ? winSep : unixSep);
 		if (pos != -1)  {
 			// Any sort of path separator found...
 			return filename.substring(pos + 1);

spring-web/src/test/java/org/springframework/web/multipart/commons/CommonsMultipartResolverTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -111,6 +111,8 @@ public class CommonsMultipartResolverTests {
 		doTestFiles(request);
 
 		doTestBinding(resolver, originalRequest, request);
+
+		wac.close();
 	}
 
 	private void doTestParameters(MultipartHttpServletRequest request) {
@@ -381,9 +383,9 @@ public class CommonsMultipartResolverTests {
 					MockFileItem fileItem1x = new MockFileItem(
 						"field1", "type1", empty ? "" : "field1.txt", empty ? "" : "text1");
 					MockFileItem fileItem2 = new MockFileItem(
-						"field2", "type2", empty ? "" : "C:/field2.txt", empty ? "" : "text2");
+						"field2", "type2", empty ? "" : "C:\\mypath/field2.txt", empty ? "" : "text2");
 					MockFileItem fileItem2x = new MockFileItem(
-						"field2x", "type2", empty ? "" : "C:\\field2x.txt", empty ? "" : "text2");
+						"field2x", "type2", empty ? "" : "C:/mypath\\field2x.txt", empty ? "" : "text2");
 					MockFileItem fileItem3 = new MockFileItem("field3", null, null, "value3");
 					MockFileItem fileItem4 = new MockFileItem("field4", "text/html; charset=iso-8859-1", null, "value4");
 					MockFileItem fileItem5 = new MockFileItem("field4", null, null, "value5");