Index: generic/nsfEnumerationType.c
===================================================================
diff -u -rd29a51c38be834fe558f1c85069d8bc500d201d9 -r92ab630ebd3c1b907e3d0fdf97cc07914245c028
--- generic/nsfEnumerationType.c	(.../nsfEnumerationType.c)	(revision d29a51c38be834fe558f1c85069d8bc500d201d9)
+++ generic/nsfEnumerationType.c	(.../nsfEnumerationType.c)	(revision 92ab630ebd3c1b907e3d0fdf97cc07914245c028)
@@ -31,8 +31,7 @@
 static int enumerationTypeRefCount = 0;
 static NsfMutex enumerationMutex = 0;
 
-static int Register(Tcl_Interp *interp, CONST char* domain, Nsf_TypeConverter *converter);
-
+static int Register(Tcl_Interp *interp, CONST char* domain, Nsf_TypeConverter *converter) nonnull(1) nonnull(3);
 /*
  *----------------------------------------------------------------------
  * Nsf_EnumerationTypeInit --
@@ -50,6 +49,8 @@
 void
 Nsf_EnumerationTypeInit(Tcl_Interp *interp) {
 
+  assert(interp);
+
   NsfMutexLock(&enumerationMutex);
   
   if (enumerationTypeRefCount == 0) {
@@ -78,6 +79,9 @@
 Nsf_EnumerationTypeRegister(Tcl_Interp *interp, Nsf_EnumeratorConverterEntry *typeRecords) {
   Nsf_EnumeratorConverterEntry *ePtr;
 
+  assert(interp);
+  assert(typeRecords);
+
   for (ePtr = typeRecords; ePtr->converter; ePtr++) {
     Register(interp, ePtr->domain, ePtr->converter);
   }
@@ -105,6 +109,8 @@
   Tcl_HashSearch hSrch;
   CONST char* domain = NULL;
 
+  assert(converter);
+
   NsfMutexLock(&enumerationMutex);
 
   for (hPtr = Tcl_FirstHashEntry(enumerationHashTablePtr, &hSrch); hPtr != NULL;
@@ -134,11 +140,15 @@
  *
  *----------------------------------------------------------------------
  */
+
 static int
 Register(Tcl_Interp *interp, CONST char* domain, Nsf_TypeConverter *converter) {
   Tcl_HashEntry *hPtr;
   int isNew;
 
+  assert(interp);
+  assert(converter);
+
   NsfMutexLock(&enumerationMutex);
   hPtr = Tcl_CreateHashEntry(enumerationHashTablePtr, domain, &isNew);
   NsfMutexUnlock(&enumerationMutex);