Don't build a veneer that points to nothing

Copy of the change in NetBSD-1_09.

Version 0.25. Tagged as 'MUSBDriver-0_25'

VersionNum

-/* (0.24)
+/* (0.25)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        0.24
+#define Module_MajorVersion_CMHG        0.25
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                15 Nov 2015
+#define Module_Date_CMHG                18 Nov 2015
 
-#define Module_MajorVersion             "0.24"
-#define Module_Version                  24
+#define Module_MajorVersion             "0.25"
+#define Module_Version                  25
 #define Module_MinorVersion             ""
-#define Module_Date                     "15 Nov 2015"
+#define Module_Date                     "18 Nov 2015"
 
-#define Module_ApplicationDate          "15-Nov-15"
+#define Module_ApplicationDate          "18-Nov-15"
 
 #define Module_ComponentName            "MUSBDriver"
 #define Module_ComponentPath            "mixed/RiscOS/Sources/HWSupport/USB/Controllers/MUSBDriver"
 
-#define Module_FullVersion              "0.24"
-#define Module_HelpVersion              "0.24 (15 Nov 2015)"
-#define Module_LibraryVersionInfo       "0:24"
+#define Module_FullVersion              "0.25"
+#define Module_HelpVersion              "0.25 (18 Nov 2015)"
+#define Module_LibraryVersionInfo       "0:25"

c/cmodule

@@ -100,6 +100,9 @@ void build_veneer (int* vn, int* st, size_t sz)
     for (i = 0; i < sz / sizeof (void*); ++i) {
         int* entry = entry_table + 2 * i;
 
+        /* if the method isn't implemented, don't veneer it */
+        if (st[i] == NULL) continue;
+
         /* copy function pointer into veneer */
         vn[i] = st[i];