removed a possible null pointer effect at route.c rtfree() start

Detail:
	if attempting to rtfree() a null rt pointer the null pointer was used to get
	initialisation for a register array before aborting. now it is only
	used if non null
Admin:


Version 5.51. Tagged as 'Internet-5_51'

VersionNum

-/* (5.50)
+/* (5.51)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.2.
  *
  */
-#define Module_MajorVersion_CMHG        5.50
+#define Module_MajorVersion_CMHG        5.51
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                18 Feb 2005
+#define Module_Date_CMHG                24 Feb 2007
 
-#define Module_MajorVersion             "5.50"
-#define Module_Version                  550
+#define Module_MajorVersion             "5.51"
+#define Module_Version                  551
 #define Module_MinorVersion             ""
-#define Module_Date                     "18 Feb 2005"
+#define Module_Date                     "24 Feb 2007"
 
-#define Module_ApplicationDate          "18-Feb-05"
+#define Module_ApplicationDate          "24-Feb-07"
 
 #define Module_ComponentName            "Internet"
 #define Module_ComponentPath            "RiscOS/Sources/Networking/AUN/Internet"
 
-#define Module_FullVersion              "5.50"
-#define Module_HelpVersion              "5.50 (18 Feb 2005)"
-#define Module_LibraryVersionInfo       "5:50"
+#define Module_FullVersion              "5.51"
+#define Module_HelpVersion              "5.51 (24 Feb 2007)"
+#define Module_LibraryVersionInfo       "5:51"

net/c/route

@@ -148,7 +148,7 @@ rtfree(rt)
 	register struct rtentry *rt;
 {
 	register struct radix_node_head *rnh =
-		rt_tables[rt_key(rt)->sa_family];
+		(rt == 0)?0:rt_tables[rt_key(rt)->sa_family];
 	register struct ifaddr *ifa;
 
 	if (rt == 0 || rnh == 0) {