### Eclipse Workspace Patch 1.0
#P jackrabbit-core
Index: src/main/java/org/apache/jackrabbit/core/query/lucene/DocOrderScoreNodeIterator.java
===================================================================
--- src/main/java/org/apache/jackrabbit/core/query/lucene/DocOrderScoreNodeIterator.java	(revision 1822206)
+++ src/main/java/org/apache/jackrabbit/core/query/lucene/DocOrderScoreNodeIterator.java	(working copy)
@@ -220,8 +220,13 @@
 
                             // check if either path is an ancestor of the other
                             if (path1.length - 1 == commonDepth) {
-                                // path1 itself is ancestor of path2
-                                return -1;
+                                if (path2.length - 1 == commonDepth) {
+                                    // same path (avoid IllegalArgumentException: Comparison method violates its general contract!)
+                                    return 0;
+                                } else {
+                                    // path1 itself is ancestor of path2
+                                    return -1;
+                                }
                             }
                             if (path2.length - 1 == commonDepth) {
                                 // path2 itself is ancestor of path1