FYI: test for PR27651 (TreePath.isDescendant)

[David Gilbert <david dot gilbert at object-refinery dot com>]

This patch (committed) checks an implementation detail for the 
TreePath.isDescendant() method.  It turns out not to isolate the bug 
reported in PR27651, but I'm committing the test anyway:

2006-05-18  David Gilbert  <david.gilbert@object-refinery.com>

   * gnu/testlet/javax/swing/tree/TreePath/PR27651.java: New test.

Regards,

Dave
Index: gnu/testlet/javax/swing/tree/TreePath/PR27651.java
===================================================================
RCS file: gnu/testlet/javax/swing/tree/TreePath/PR27651.java
diff -N gnu/testlet/javax/swing/tree/TreePath/PR27651.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ gnu/testlet/javax/swing/tree/TreePath/PR27651.java	18 May 2006 09:40:26 -0000
@@ -0,0 +1,121 @@
+/* PR27651.java -- a check related to PR27651
+   Copyright (C) 2006 David Gilbert <david.gilbert@object-refinery.com>
+This file is part of Mauve.
+
+Mauve is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+Mauve is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Mauve; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+*/
+
+// Tags: JDK1.2
+
+package gnu.testlet.javax.swing.tree.TreePath;
+
+import gnu.testlet.TestHarness;
+import gnu.testlet.Testlet;
+
+import javax.swing.tree.TreePath;
+
+public class PR27651 implements Testlet
+{
+  static class A
+  {
+    String id;
+    
+    public A(String id)
+    {
+      if (id == null)
+        id = "";
+      this.id = id;
+    }
+    
+    public boolean equals(Object obj)
+    {
+      if (obj == this)
+        return true;
+      if (obj instanceof A)
+        {
+          A that = (A) obj;
+          return this.id.equals(that.id);
+        }
+      return false;
+    }
+  }
+  
+  static class B extends A
+  {
+    int index;
+    
+    public B(String id, int index)
+    {
+      super(id);
+      this.index = index;
+    }
+
+    /**
+     * Throws a ClassCastException if obj is not an instanceof B.
+     */
+    public boolean equals(Object obj)
+    {
+      if (obj == this)
+        return true;
+      if (! super.equals(obj))
+        return false;
+      B that = (B) obj;
+      return (this.index == that.index);
+    } 
+    
+  }
+
+  /**
+   * This checks an implementation detail - that the reference implementation
+   * calls objA.equals(objB) within the TreePath.isDescendant() method, and
+   * not the reverse.
+   */
+  public void test(TestHarness harness)
+  {
+    A objA = new A("ABC");
+    B objB = new B("ABC", 99);
+    
+    // confirm that objA.equals(objB) is true, but the reverse throws a 
+    // ClassCastException...
+    harness.check(objA.equals(objB));
+    boolean pass = false;
+    try
+      {
+        objB.equals(objA);
+      }
+    catch (ClassCastException e)
+      {
+        pass = true;
+      }
+    harness.check(pass);
+    
+    TreePath p1 = new TreePath(objA);
+    TreePath p2 = new TreePath(objB);
+    harness.check(p1.isDescendant(p2));
+    
+    pass = false;
+    try
+      {
+        p2.isDescendant(p1);
+      }
+    catch (ClassCastException e)
+      {
+        pass = true;    
+      }
+    harness.check(pass);
+  }
+}