removeLeadingPath didn't work as expected when trying to remove a path

from itself.
PR: 19979


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@274596 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/util/FileUtils.java

@@ -988,12 +988,16 @@ public class FileUtils {
      * @since Ant 1.5
      */
     public String removeLeadingPath(File leading, File path) {
+        String l = normalize(leading.getAbsolutePath()).getAbsolutePath();
+        String p = normalize(path.getAbsolutePath()).getAbsolutePath();
+        if (l.equals(p)) {
+            return "";
+        }
+
         // if leading's path ends with a slash, it will be stripped by
         // normalize - we always add one so we never think /foo was a
         // parent directory of /foobar
-        String l = normalize(leading.getAbsolutePath()).getAbsolutePath()
-            + File.separator;
-        String p = normalize(path.getAbsolutePath()).getAbsolutePath();
+        l += File.separator;
         if (p.startsWith(l)) {
             return p.substring(l.length());
         } else {

src/testcases/org/apache/tools/ant/util/FileUtilsTest.java

@@ -1,7 +1,7 @@
 /*
  * The Apache Software License, Version 1.1
  *
- * Copyright (c) 2001-2002 The Apache Software Foundation.  All rights
+ * Copyright (c) 2001-2003 The Apache Software Foundation.  All rights
  * reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -406,6 +406,15 @@ public class FileUtilsTest extends TestCase {
                      fu.removeLeadingPath(new File("/foo"), new File("/bar")));
         assertEquals(fu.normalize("/foobar").getAbsolutePath(), 
                      fu.removeLeadingPath(new File("/foo"), new File("/foobar")));
+        // bugzilla report 19979
+        assertEquals("", fu.removeLeadingPath(new File("/foo/bar"), 
+                                              new File("/foo/bar")));
+        assertEquals("", fu.removeLeadingPath(new File("/foo/bar"), 
+                                              new File("/foo/bar/")));
+        assertEquals("", fu.removeLeadingPath(new File("/foo/bar/"), 
+                                              new File("/foo/bar/")));
+        assertEquals("", fu.removeLeadingPath(new File("/foo/bar/"), 
+                                              new File("/foo/bar")));
     }
 
     /**