Index: trunk/ppMerge/src/ppMergeCheckInputs.c
===================================================================
--- trunk/ppMerge/src/ppMergeCheckInputs.c	(revision 7000)
+++ trunk/ppMerge/src/ppMergeCheckInputs.c	(revision 7002)
@@ -15,4 +15,7 @@
     for (int i = 0; i < filenames->n; i++) {
         psString name = filenames->data[i]; // The name of the file
+        if (!name || strlen(name) == 0) {
+            continue;
+        }
         psFits *inFile = psFitsOpen(filenames->data[i], "r"); // The FITS file to read
         if (!inFile) {