Index: gateway/gw/smsc/smsc_at.c
===================================================================
RCS file: /home/cvs/gateway/gw/smsc/smsc_at.c,v
retrieving revision 1.29
diff -u -b -B -u -r1.29 smsc_at.c
--- gateway/gw/smsc/smsc_at.c	24 Apr 2006 21:32:01 -0000	1.29
+++ gateway/gw/smsc/smsc_at.c	9 May 2006 12:03:22 -0000
@@ -2649,13 +2649,20 @@
 			    );
 
     /* grab the digits from the MSISDN and encode as swapped semi-octets */
-    while (octstr_len(temp)) {
+    while ((out)&&(octstr_len(temp))) {
 	int digit1, digit2;
 	/* get the first two digit */
 	digit1 = octstr_get_char(temp,0) - 48;
-	if ((digit2 = octstr_get_char(temp,1) - 48) < 0)
+        digit2 = octstr_get_char(temp,1) - '0';
+        if (digit2 < 0)
 	    digit2 = 0x0F;
+        if((digit1>=0)&&(digit1<16)&&(digit2<16)) {
 	octstr_append_char(out, (digit2 << 4) | digit1);
+        }
+        else {
+            O_DESTROY(out);
+            out = NULL;
+        }
 	octstr_delete(temp, 0, 2);
     }