Index: TODO
===================================================================
diff -u -rb4318730d5cb6a1dbb095283c27325acd4d3b9be -r472a3c5f359bb9b2d0aeadc7937ba2bc6aecdbc9
--- TODO	(.../TODO)	(revision b4318730d5cb6a1dbb095283c27325acd4d3b9be)
+++ TODO	(.../TODO)	(revision 472a3c5f359bb9b2d0aeadc7937ba2bc6aecdbc9)
@@ -5873,6 +5873,7 @@
 - Added Rosetta example: https://rosettacode.org/wiki/Inheritance/Single
 
 - new subcommand "nsf::current level", returns empty, if we are not on a nsf frame/level.
+- improve sanity test in ISOBJ(): obj->bytes might only be NULL when type is given.
 
 ========================================================================
 TODO:
@@ -5883,9 +5884,6 @@
 
 - Under core-8-5-branch, make test --enable-development yields an assertion failure:
 
-  ./tests/parameters.test
-  Assertion failed: (ISOBJ(objv[pcPtr->lastObjc-1])), function ArgumentParse, file ./generic/nsf.c, line 22155.
-
 - Should we add exists to the Variableslot-Interface, to surface ::nsf::var::exists.
 
 +  ::nx::VariableSlot public method value=exists {obj prop} {
Index: generic/nsf.c
===================================================================
diff -u -r77ba24ec459d9168dbfad4ae0c6eb4b936e8ea6b -r472a3c5f359bb9b2d0aeadc7937ba2bc6aecdbc9
--- generic/nsf.c	(.../nsf.c)	(revision 77ba24ec459d9168dbfad4ae0c6eb4b936e8ea6b)
+++ generic/nsf.c	(.../nsf.c)	(revision 472a3c5f359bb9b2d0aeadc7937ba2bc6aecdbc9)
@@ -21890,7 +21890,14 @@
     }
     fprintf(stderr, "\n");
     fprintf(stderr, "BEGIN (%d) [0]%s ", objc, ObjStr(procNameObj));
-    for (o = fromArg; o < objc; o++) {fprintf(stderr, "[%d]%s ", o, ObjStr(objv[o]));}
+    for (o = fromArg; o < objc; o++) {
+      Tcl_Obj *obj = objv[o];
+      if (obj->bytes == NULL) {
+        fprintf(stderr, "[%d]unk(%s) ", o, obj->typePtr->name);
+      } else {
+        fprintf(stderr, "[%d]%s ", o, ObjStr(obj));
+      }
+    }
     fprintf(stderr, "\n");
   }
 #endif
@@ -22175,7 +22182,7 @@
 
 
 #if defined(PARSE_TRACE_FULL)
-      fprintf(stderr, "... args found o %d objc %d is dashdash %d [%d] <%s>\n", o, objc, dashdash, j, ObjStr(argumentObj));
+      fprintf(stderr, "... args found o %d objc %d is dashdash %d [%ld] <%s>\n", o, objc, dashdash, j, ObjStr(argumentObj));
 #endif
       break;
 
@@ -22210,7 +22217,7 @@
     }
 
 #if defined(PARSE_TRACE_FULL)
-    fprintf(stderr, "... setting parameter %s pos %d valueObj '%s'\n",
+    fprintf(stderr, "... setting parameter %s pos %ld valueObj '%s'\n",
             pPtr->name, j,
             valueObj == argumentObj ? "=" : ObjStr(valueObj));
 #endif
@@ -24979,7 +24986,7 @@
     /*
      * No need to parse arguments (local, intrinsic, ...).
      */
-    return ObjectDispatch(self, interp, nobjc, nobjv, 0);
+    return ObjectDispatch(self, interp, nobjc, nobjv, 0u);
   } else {
     ParseContext pc;
     int          withIntrinsic, withLocal, withSystem;
Index: generic/nsfInt.h
===================================================================
diff -u -r77ba24ec459d9168dbfad4ae0c6eb4b936e8ea6b -r472a3c5f359bb9b2d0aeadc7937ba2bc6aecdbc9
--- generic/nsfInt.h	(.../nsfInt.h)	(revision 77ba24ec459d9168dbfad4ae0c6eb4b936e8ea6b)
+++ generic/nsfInt.h	(.../nsfInt.h)	(revision 472a3c5f359bb9b2d0aeadc7937ba2bc6aecdbc9)
@@ -271,10 +271,10 @@
 #if !defined(NDEBUG)
 # if defined(PRE86)
 #  define ISOBJ(o) ((o) != NULL && ISOBJ_(o))
-#  define ISOBJ_(o) ((o) != (void*)0xdeadbeaf && ((o)->typePtr ? (o)->typePtr->name != NULL : 1) && (o)->length >= -1 && ((o)->length > 0 ? (o)->bytes!= NULL : 1) && (o)->refCount >= 0)
+#  define ISOBJ_(o) ((o) != (void*)0xdeadbeaf && ((o)->typePtr ? ((o)->typePtr->name != NULL) : ((o)->bytes != NULL)) && (o)->length >= -1 && (o)->refCount >= 0)
 #  else
 #  define ISOBJ(o) ((o) != NULL && ISOBJ_(o))
-#  define ISOBJ_(o) ((o) != (void*)0xdeadbeaf && ((o)->typePtr ? (o)->typePtr->name != NULL : 1) && ((o)->bytes != NULL ? (o)->length >= 0 : 1) && (o)->refCount >= 0)
+#  define ISOBJ_(o) ((o) != (void*)0xdeadbeaf && ((o)->typePtr ? (o)->typePtr->name != NULL : ((o)->bytes != NULL)) && ((o)->bytes != NULL ? (o)->length >= 0 : 1) && (o)->refCount >= 0)
 # endif
 #else
 # define ISOBJ(o) ((o) != NULL && ISOBJ_(o))