Index: trunk/stac/src/stacRead.c
===================================================================
--- trunk/stac/src/stacRead.c	(revision 6485)
+++ trunk/stac/src/stacRead.c	(revision 6771)
@@ -24,9 +24,13 @@
         psTrace("stac.read.images", 2, "Reading input image %s....\n",filenames->data[i]);
         psFits *imageFile = psFitsOpen(filenames->data[i], "r");
+        if (!imageFile) {
+            psError(PS_ERR_IO, false, "Unable to open FITS file %s.\n", filenames->data[i]);
+            exit(EXIT_FAILURE);
+        }
         // We only read PHUs --- not mucking around with extensions for now
         if (headers) {
             (*headers)->data[i] = psFitsReadHeader(NULL, imageFile);
         }
-        psImage *image = psFitsReadImage(NULL, imageFile, imageRegion, 0);
+        psImage *image = psFitsReadImage(imageFile, imageRegion, 0);
         if (image == NULL) {
             psErrorStackPrint(stderr,"Fatal error: Unable to read %s\n",filenames->data[i]);