Index: trunk/src/org/openstreetmap/josm/gui/dialogs/validator/ValidatorTreePanel.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/dialogs/validator/ValidatorTreePanel.java	(revision 6466)
+++ trunk/src/org/openstreetmap/josm/gui/dialogs/validator/ValidatorTreePanel.java	(revision 6468)
@@ -131,4 +131,6 @@
             return;
         }
+        // Sort validation errors - #8517
+        Collections.sort(errors);
 
         // Remember the currently expanded rows