If someone tries to append a path to itself, choke gracefully, not with a StackOverflowError.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@470125 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/types/Path.java

@@ -19,7 +19,6 @@
 package org.apache.tools.ant.types;
 
 import java.io.File;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.Locale;
@@ -238,6 +237,9 @@ public class Path extends DataType implements Cloneable, ResourceCollection {
      * @since Ant 1.6
      */
     public void add(Path path) throws BuildException {
+        if (path == this) {
+            throw circularReference();
+        }
         if (path.getProject() == null) {
             path.setProject(getProject());
         }

src/tests/junit/org/apache/tools/ant/types/PathTest.java

@@ -549,4 +549,15 @@ public class PathTest extends TestCase {
         assertEquals(project.resolveFile("build").getAbsolutePath(), l[0]);
     }
 
+    public void testRecursion() {
+        Path p = new Path(project);
+        try {
+            p.append(p);
+            assertEquals(0, p.list().length);
+        } catch (BuildException x) {
+            String m = x.toString();
+            assertTrue(m, m.indexOf("circular") != -1);
+        }
+    }
+
 }