Index: TODO
===================================================================
diff -u -r56fc3af13d127cdfa54db9c89e8d44308b72bba9 -rbd92cf0fcf5cb4388749a10ab542bf0199b00761
--- TODO	(.../TODO)	(revision 56fc3af13d127cdfa54db9c89e8d44308b72bba9)
+++ TODO	(.../TODO)	(revision bd92cf0fcf5cb4388749a10ab542bf0199b00761)
@@ -2822,17 +2822,24 @@
 - migration-guide: add third level to toc
 - fix regression test for 8.6 to use nx prefix
 
+- nsf.c: added cmd "::nsd::method::registered /handle/" that returns
+  the object on which the method identified by the handle was registered,
+  or empty.
+- extended regression test
+
+
 TODO:
 
 - add "link" form 2.4 (parameters) to "info parameters"
 
 - MixinComputeOrderFullList() could receive a flag to store source classes in checkList
 
 - if the check on eg. info-heritage-circular in test/info.method.tcl
-  fails, we get an exception.
+  reports a warning on exit, if  we get an exception.
+- should be be concerned about message like
+  DEBUG obj 0x100227960 ::nx::Object activationcount 2 on stack 3; might be from non-stacked but active callstack content
+ in the regression test?
 
-- ::nsf::method::exists /handle/ -> check, if handle is a handle of a registered method
-  (to be be used in serializer alias-dependency)
 - profiling missing when NSF_INVOKE_SHADOWED_TRADITIONAL is turned off.
 
 - maybe change nx::Test to nx::test (user never has to know that nx::Test is a class).
Index: generic/gentclAPI.decls
===================================================================
diff -u -re29434ffef30bea10b7422f1f295787d41377839 -rbd92cf0fcf5cb4388749a10ab542bf0199b00761
--- generic/gentclAPI.decls	(.../gentclAPI.decls)	(revision e29434ffef30bea10b7422f1f295787d41377839)
+++ generic/gentclAPI.decls	(.../gentclAPI.decls)	(revision bd92cf0fcf5cb4388749a10ab542bf0199b00761)
@@ -102,6 +102,9 @@
   {-argName "methodproperty" -required 1 -type "class-only|call-protected|redefine-protected|returns|slotcontainer|slotobj"}
   {-argName "value" -type tclobj}
 }
+cmd "method::registered" NsfMethodRegisteredCmd {
+  {-argName "handle" -required 1 -type tclobj}
+}
 cmd "method::setter" NsfSetterCmd {
   {-argName "object" -required 1 -type object}
   {-argName "-per-object"}
Index: generic/nsf.c
===================================================================
diff -u -r046e5f798cbb4ce5473fb11da8e63a3db998a376 -rbd92cf0fcf5cb4388749a10ab542bf0199b00761
--- generic/nsf.c	(.../nsf.c)	(revision 046e5f798cbb4ce5473fb11da8e63a3db998a376)
+++ generic/nsf.c	(.../nsf.c)	(revision bd92cf0fcf5cb4388749a10ab542bf0199b00761)
@@ -16431,6 +16431,33 @@
 }
 
 /*
+cmd "method::registered" NsfMethodRegisteredCmd {
+  {-argName "handle" -required 1 -type tclobj}
+}
+*/
+static int
+NsfMethodRegisteredCmd(Tcl_Interp *interp, Tcl_Obj *methodNameObj) {
+  NsfObject *regObject, *defObject;
+  CONST char *methodName1 = NULL;
+  int fromClassNS = 0;
+  Tcl_DString ds, *dsPtr = &ds;
+  Tcl_Command cmd;
+
+  Tcl_DStringInit(dsPtr);
+  cmd = ResolveMethodName(interp, NULL, methodNameObj,
+			  dsPtr, &regObject, &defObject, &methodName1, &fromClassNS);
+  /*
+   * In case the provided cmd is fully qualified and refers to a registered
+   * method, the function returns the object, on which the method was
+   * registed.
+   */
+  Tcl_SetObjResult(interp, (cmd && regObject) ? regObject->cmdName : NsfGlobalObjs[NSF_EMPTY]);
+
+  Tcl_DStringFree(dsPtr);
+  return TCL_OK;
+}
+
+/*
 nsfCmd my NsfMyCmd {
   {-argName "-local"}
   {-argName "method" -required 1 -type tclobj}
Index: generic/tclAPI.h
===================================================================
diff -u -re29434ffef30bea10b7422f1f295787d41377839 -rbd92cf0fcf5cb4388749a10ab542bf0199b00761
--- generic/tclAPI.h	(.../tclAPI.h)	(revision e29434ffef30bea10b7422f1f295787d41377839)
+++ generic/tclAPI.h	(.../tclAPI.h)	(revision bd92cf0fcf5cb4388749a10ab542bf0199b00761)
@@ -237,6 +237,7 @@
 static int NsfMethodCreateCmdStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMethodDeleteCmdStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMethodPropertyCmdStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
+static int NsfMethodRegisteredCmdStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMyCmdStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfNSCopyCmdsCmdStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfNSCopyVarsCmdStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
@@ -329,6 +330,7 @@
 static int NsfMethodCreateCmd(Tcl_Interp *interp, NsfObject *object, int withInner_namespace, int withPer_object, NsfObject *withReg_object, Tcl_Obj *methodName, Tcl_Obj *arguments, Tcl_Obj *body, Tcl_Obj *withPrecondition, Tcl_Obj *withPostcondition);
 static int NsfMethodDeleteCmd(Tcl_Interp *interp, NsfObject *object, int withPer_object, Tcl_Obj *methodName);
 static int NsfMethodPropertyCmd(Tcl_Interp *interp, NsfObject *object, int withPer_object, Tcl_Obj *methodName, int methodproperty, Tcl_Obj *value);
+static int NsfMethodRegisteredCmd(Tcl_Interp *interp, Tcl_Obj *handle);
 static int NsfMyCmd(Tcl_Interp *interp, int withLocal, Tcl_Obj *methodName, int nobjc, Tcl_Obj *CONST nobjv[]);
 static int NsfNSCopyCmdsCmd(Tcl_Interp *interp, Tcl_Obj *fromNs, Tcl_Obj *toNs);
 static int NsfNSCopyVarsCmd(Tcl_Interp *interp, Tcl_Obj *fromNs, Tcl_Obj *toNs);
@@ -422,6 +424,7 @@
  NsfMethodCreateCmdIdx,
  NsfMethodDeleteCmdIdx,
  NsfMethodPropertyCmdIdx,
+ NsfMethodRegisteredCmdIdx,
  NsfMyCmdIdx,
  NsfNSCopyCmdsCmdIdx,
  NsfNSCopyVarsCmdIdx,
@@ -1343,6 +1346,22 @@
 }
 
 static int
+NsfMethodRegisteredCmdStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
+  (void)clientData;
+
+    
+
+      if (objc != 2) {
+	return NsfArgumentError(interp, "wrong # of arguments:", 
+			     method_definitions[NsfMethodRegisteredCmdIdx].paramDefs,
+			     NULL, objv[0]); 
+      }
+    
+    return NsfMethodRegisteredCmd(interp, objc == 2 ? objv[1] : NULL);
+
+}
+
+static int
 NsfMyCmdStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
   ParseContext pc;
   (void)clientData;
@@ -2442,6 +2461,9 @@
   {"methodproperty", NSF_ARG_REQUIRED|NSF_ARG_IS_ENUMERATION, 0, ConvertToMethodproperty, NULL,NULL,NULL,NULL,NULL,NULL,NULL},
   {"value", 0, 0, Nsf_ConvertToTclobj, NULL,NULL,NULL,NULL,NULL,NULL,NULL}}
 },
+{"::nsf::method::registered", NsfMethodRegisteredCmdStub, 1, {
+  {"handle", NSF_ARG_REQUIRED, 0, Nsf_ConvertToTclobj, NULL,NULL,NULL,NULL,NULL,NULL,NULL}}
+},
 {"::nsf::my", NsfMyCmdStub, 3, {
   {"-local", 0, 0, Nsf_ConvertToString, NULL,NULL,NULL,NULL,NULL,NULL,NULL},
   {"methodName", NSF_ARG_REQUIRED, 0, Nsf_ConvertToTclobj, NULL,NULL,NULL,NULL,NULL,NULL,NULL},
Index: library/serialize/serializer.tcl
===================================================================
diff -u -r5972bd087afec6d23d1192d552a29c92e570d8a6 -rbd92cf0fcf5cb4388749a10ab542bf0199b00761
--- library/serialize/serializer.tcl	(.../serializer.tcl)	(revision 5972bd087afec6d23d1192d552a29c92e570d8a6)
+++ library/serialize/serializer.tcl	(.../serializer.tcl)	(revision bd92cf0fcf5cb4388749a10ab542bf0199b00761)
@@ -674,17 +674,15 @@
 	#
 	# The aliasedCmd is fully qualified and could be a method
 	# handle or a primitive cmd.  For a primitive cmd, we have no
-	# alias dependency. Currently we check here only, of we can
-	# obtain the method definition for this handle. It would be
-	# better to use ::nsf::method::exists when implemented.
+	# alias dependency. If the cmd is registed on an object, we
+	# report the dependency.
 	#
-	set source [::nx::Object ::nsf::methods::class::info::method definition $aliasedCmd]
-	if {$source ne ""} {
-	  set obj [lindex $source 0]
-	  if {$obj eq $x} {
+	set regObj [::nsf::method::registered $aliasedCmd]
+	if {$regObj ne ""} {
+	  if {$regObj eq $x} {
 	    :warn "Dependency for alias $alias from $x to $x not handled (no guarantee on method order)"
 	  } else {
-	    lappend needed [lindex $source 0]
+	    lappend needed $regObj
 	  }
 	}
       }
Index: tests/info-method.test
===================================================================
diff -u -r679a4d086fb9b8a728e0d33f5fa6520f2ce2f954 -rbd92cf0fcf5cb4388749a10ab542bf0199b00761
--- tests/info-method.test	(.../info-method.test)	(revision 679a4d086fb9b8a728e0d33f5fa6520f2ce2f954)
+++ tests/info-method.test	(.../info-method.test)	(revision bd92cf0fcf5cb4388749a10ab542bf0199b00761)
@@ -897,4 +897,38 @@
   ? {B info mixin classes -heritage} "::TPCMB ::TPCMA ::PCMB ::PCMA ::A"
   ? {C info mixin classes -heritage} "::PCMC ::TPCMB ::TPCMA ::PCMB ::PCMA ::A"
 
+}
+
+#
+# ::nsf::method::ishandle
+#
+nx::Test case method-isregistered {
+  
+  ? {::nsf::method::registered c} ""
+  ? {::nsf::method::registered info} ""
+  ? {::nsf::method::registered ::info} ""
+
+  Class create C {
+    :method bar {} {return bar}
+    set h1 [:info method handle bar]
+    ? [list set _ $h1] "::nsf::classes::C::bar"
+    ? [list [self] info method handle bar] "::nsf::classes::C::bar"
+
+    ? [list ::nsf::method::registered $h1] ::C
+
+    :class method bar {} {return bar}
+    set h2 [:class info method handle bar]
+    ? [list [self] class info method handle bar] "::C::bar"
+
+    ? [list ::nsf::method::registered $h2] ::C
+  }
+
+  Object create o {
+    :method bar {} {return bar}
+    set h1 [:info method handle bar]
+    ? [list set _ $h1] "::o::bar"
+    ? [list [self] info method handle bar] "::o::bar"
+
+    ? [list ::nsf::method::registered $h1] ::o
+  }
 }
\ No newline at end of file