Index: /branches/eam_branches/ipp-20140610/Ohana/src/dvomerge/src/dvomergeUpdate_catalogs.c
===================================================================
--- /branches/eam_branches/ipp-20140610/Ohana/src/dvomerge/src/dvomergeUpdate_catalogs.c	(revision 37011)
+++ /branches/eam_branches/ipp-20140610/Ohana/src/dvomerge/src/dvomergeUpdate_catalogs.c	(revision 37012)
@@ -140,4 +140,9 @@
     }
 
+    if (!incatalog.sorted) {
+      fprintf (stderr, "ERROR: input catalog %s is not sorted (and must be for dvomerge)\n", filename_input);
+      exit (1);
+    }
+
     dvo_update_image_IDs (IDmap, &incatalog);