Index: /branches/eam_branches/largefiles.20100314/Ohana/src/libfits/header/F_H_field.c
===================================================================
--- /branches/eam_branches/largefiles.20100314/Ohana/src/libfits/header/F_H_field.c	(revision 27377)
+++ /branches/eam_branches/largefiles.20100314/Ohana/src/libfits/header/F_H_field.c	(revision 27378)
@@ -9,4 +9,6 @@
   int Nwant, Nfound;
   char keyword[10];
+
+  if (header[0].buffer == NULL) return NULL;
 
   /* create a blank-padded keyword with exactly 8 characters */
@@ -51,5 +53,5 @@
   }
 
-  return ((char *) NULL);
+  return NULL;
 
 /* 
@@ -69,4 +71,6 @@
   off_t i;
   int Nwant, Nfound, Nfield;
+
+  if (header[0].buffer == NULL) return NULL;
 
   Nfield = strlen (field);
@@ -113,5 +117,5 @@
   }
 
-  return ((char *) NULL);
+  return NULL;
 
 /*