Index: generic/nsf.c
===================================================================
diff -u -r9318621f9cf5544818fbb03209814fdfc8d2156c -r16494e7f90f6b80bea8eacb3d018f1383651904b
--- generic/nsf.c	(.../nsf.c)	(revision 9318621f9cf5544818fbb03209814fdfc8d2156c)
+++ generic/nsf.c	(.../nsf.c)	(revision 16494e7f90f6b80bea8eacb3d018f1383651904b)
@@ -19101,10 +19101,11 @@
     }
     break;
 
-  case CurrentoptionCalledclassIdx:
-    Tcl_SetResult(interp, ClassName(FindCalledClass(interp, object)), TCL_VOLATILE);
+  case CurrentoptionCalledclassIdx: {
+    NsfClass *cl = FindCalledClass(interp, object);
+    Tcl_SetObjResult(interp, cl ? cl->object.cmdName : NsfGlobalObjs[NSF_EMPTY]);
     break;
-
+  }
   case CurrentoptionCallingmethodIdx:
   case CurrentoptionCallingprocIdx: {
     Tcl_Obj *resultObj;
Index: library/lib/test.tcl
===================================================================
diff -u -r7045595af282428ca760d1d5f9351d561a43bb51 -r16494e7f90f6b80bea8eacb3d018f1383651904b
--- library/lib/test.tcl	(.../test.tcl)	(revision 7045595af282428ca760d1d5f9351d561a43bb51)
+++ library/lib/test.tcl	(.../test.tcl)	(revision 16494e7f90f6b80bea8eacb3d018f1383651904b)
@@ -120,10 +120,9 @@
 	#
 	# Gracefully unwind the callstack built-up to this point, by
 	# using [return]. At the top-most callstack level, we return
-	# with TCL_OK which will end the script evaluation without any
-	# error handling noise. We simply stop. By first returning to
-	# the very top of the callstack, we allow NSF to cleanup
-	# behind itself at the various dispatch levels
+	# with TCL_ERROR which will end the script evaluation. By
+	# first returning to the very top of the callstack, we allow
+	# NSF to cleanup behind itself at the various dispatch levels
 	# (ObjectDispatch, MethodDispatch(), ...).
 	#
 	# Using [exit -1] directly leaves us with a partially unwinded
@@ -133,10 +132,10 @@
 	# effectively skips the cleanup blocks throughout the NSF method
 	# dispatch chain.
 	#
+	
+	# exit -1 
+	return -code error; # return -level [expr {[info level]-1}] -code error
 
-	#return -level [expr {[info level]-1}] -code ok; # exit -1
-	return -code error
-
       }
       if {[info exists :post]} {:call "post" ${:post}}
     }
Index: tests/interp.test
===================================================================
diff -u -r9318621f9cf5544818fbb03209814fdfc8d2156c -r16494e7f90f6b80bea8eacb3d018f1383651904b
--- tests/interp.test	(.../interp.test)	(revision 9318621f9cf5544818fbb03209814fdfc8d2156c)
+++ tests/interp.test	(.../interp.test)	(revision 16494e7f90f6b80bea8eacb3d018f1383651904b)
@@ -498,17 +498,4 @@
   ? {interp eval $i {nsf::object::exists ::o}} 0
 
   interp delete $i 
-}
-
-#
-# TODO: 
-# - [current calledclass] seems broken -> returns NULL as string value?!
-# - renames to "" in destroy run into an endless loop: 
-# nx::Object create ::o {
-#   :public method destroy {} {
-#     ::rename [current] ""
-#     next
-#   }
-#   :destroy
-# }
-# #
\ No newline at end of file
+}
\ No newline at end of file
Index: tests/introspection.test
===================================================================
diff -u
--- tests/introspection.test	(revision 0)
+++ tests/introspection.test	(revision 16494e7f90f6b80bea8eacb3d018f1383651904b)
@@ -0,0 +1,49 @@
+# -*- Tcl -*-
+package req nx::test
+
+#
+# [::nsf::current calledclass]
+#
+
+nx::Test case current-calledclass {
+  Object create o {
+    :public method foo {} {
+      return [current calledclass]
+    }
+  }
+  ? {o foo} ""
+  Class create C {
+    :public class method bar {} {
+      return [current calledclass]
+    }
+    :public method foo {} {
+      return [current calledclass]
+    }
+  }
+  ? {[C new] foo} ::C
+  ? {C bar} ""
+  
+  C eval {
+    :public method intercept {} {
+      return @[current calledclass]@
+    }
+    :filter add intercept
+  }
+  ? {[C new] foo} @::C@
+
+  C eval {
+    :filter {}
+    :public method baz {} {
+      return [current calledclass]
+    }
+  }
+
+  Class create M {
+    :public method baz {} {
+      return [list [current calledclass] [next]]
+    }
+  }
+  C mixin add M
+
+  ? {[C new] baz} {::C ::C}
+}
\ No newline at end of file