Index: trunk/Ohana/src/libdvo/src/dvo_photcode_ops.c
===================================================================
--- trunk/Ohana/src/libdvo/src/dvo_photcode_ops.c	(revision 17245)
+++ trunk/Ohana/src/libdvo/src/dvo_photcode_ops.c	(revision 17253)
@@ -320,4 +320,6 @@
   int i, Np; 
   float Mcal, Mrel, Mcol, mc, Mc;
+
+  if (code == NULL) return NAN;
 
   /* code must be the matching PRI/SEC code for this measurement or an equivalent ALT */
@@ -404,4 +406,6 @@
   double Mc;
 
+  if (code == NULL) return NAN;
+
   Ns = photcodes[0].hashNsec[code[0].code];
   Mave = (Ns == -1) ? NAN : secfilt[Ns].M;
@@ -428,4 +432,6 @@
   float Mave;
 
+  if (code == NULL) return NAN;
+
   Ns = photcodes[0].hashNsec[code[0].code];
   Mave = (Ns == -1) ? NAN : secfilt[Ns].M;
@@ -438,4 +444,6 @@
   float dM;
 
+  if (code == NULL) return NAN;
+
   Ns = photcodes[0].hashNsec[code[0].code];
   dM  = (Ns == -1) ? NAN : secfilt[Ns].dM;
@@ -449,4 +457,6 @@
   short Mi;
   float Xm;
+
+  if (code == NULL) return NAN;
 
   Ns = photcodes[0].hashNsec[code[0].code];