Index: trunk/ppStack/src/ppStackSources.c
===================================================================
--- trunk/ppStack/src/ppStackSources.c	(revision 18383)
+++ trunk/ppStack/src/ppStackSources.c	(revision 18384)
@@ -120,5 +120,5 @@
     list->bounds = NULL;
     list->indices = NULL;
-    list->duplicates = NULL;
+    list->duplicates = psArrayAllocEmpty(0);
 
     psVector *x = NULL, *y = NULL;      // Source coordinates