Index: configure
===================================================================
diff -u -r5ec6a6f960964d861d68c052d8e2e7d68b711449 -rcde16e9d87173d7ef9179ce40e10c2f1f708940e
--- configure	(.../configure)	(revision 5ec6a6f960964d861d68c052d8e2e7d68b711449)
+++ configure	(.../configure)	(revision cde16e9d87173d7ef9179ce40e10c2f1f708940e)
@@ -11748,11 +11748,15 @@
 fi
 
 
+echo "==================== building genstubs (needed for Tcl 8.6)"
+make genstubs
+echo "==================== genstubs built"
+
 here=${PWD}
 
 for subdir in ${subdirs}
 do
-	echo "==================== configure $subdir ====================="
+	echo "==================== configure $subdir"
 	if test x"${srcdir}" = x. ; then
 		confdir=.
 	else
Index: configure.in
===================================================================
diff -u -r5ec6a6f960964d861d68c052d8e2e7d68b711449 -rcde16e9d87173d7ef9179ce40e10c2f1f708940e
--- configure.in	(.../configure.in)	(revision 5ec6a6f960964d861d68c052d8e2e7d68b711449)
+++ configure.in	(.../configure.in)	(revision cde16e9d87173d7ef9179ce40e10c2f1f708940e)
@@ -460,11 +460,15 @@
 
 AC_OUTPUT
 
+echo "==================== building genstubs (needed for Tcl 8.6)"
+make genstubs
+echo "==================== genstubs built"
+
 here=${PWD}
 
 for subdir in ${subdirs}
 do
-	echo "==================== configure $subdir ====================="
+	echo "==================== configure $subdir"
 	if test x"${srcdir}" = x. ; then
 		confdir=.
 	else
Index: generic/xotcl.c
===================================================================
diff -u -rd4e66214fc3323aea509676709c9b7ace64f0f50 -rcde16e9d87173d7ef9179ce40e10c2f1f708940e
--- generic/xotcl.c	(.../xotcl.c)	(revision d4e66214fc3323aea509676709c9b7ace64f0f50)
+++ generic/xotcl.c	(.../xotcl.c)	(revision cde16e9d87173d7ef9179ce40e10c2f1f708940e)
@@ -5224,7 +5224,6 @@
      * but we have to check what happens in the finish target etc.
      */
     XOTcl_PushFrameCsc(interp, obj, cscPtr);
-    /*fprintf(stderr, "pushing callframe for %s\n",methodName);*/
     /*XOTcl_PushFrame(interp, obj);*/
   }
 #endif
@@ -5290,12 +5289,12 @@
              Tcl_Command cmd, XOTclObject *obj, XOTclClass *cl,
              char *methodName, int frameType) {
   ClientData cp = Tcl_Command_objClientData(cmd);
-  XOTclCallStackContent *cscPtr;
+  XOTclCallStackContent csc, *cscPtr;
   register Tcl_ObjCmdProc *proc = Tcl_Command_objProc(cmd); 
   int result;
 
   assert (!obj->teardown);
-  /*fprintf(stderr, "InvokeMethod method '%s' cmd %p cp=%p objc=%d\n",methodName,cmd, cp, objc);*/
+  /*fprintf(stderr, "InvokeMethod method '%s' cmd %p cp=%p objc=%d\n", methodName, cmd, cp, objc);*/
 
   if (proc == TclObjInterpProc) {
 #if defined(NRE)
@@ -5304,7 +5303,6 @@
     fprintf(stderr, "---- csc alloc %p method %s\n", cscPtr, methodName);
 # endif
 #else
-    XOTclCallStackContent csc;
     cscPtr = &csc;
 #endif
     /*
@@ -5326,7 +5324,6 @@
     return result;
 
   } else if (cp) {
-    XOTclCallStackContent csc;
     cscPtr = &csc;
 
     /* some cmd with client data */
@@ -5369,6 +5366,7 @@
   }
   result = invokeCmdMethod(cp, interp, objc, objv, methodName, obj, cmd, cscPtr);
   if (cscPtr) {
+    /* make sure, that csc is still in the scope; therefore, csc is currently on the top scope of this function */
     CallStackPop(interp, cscPtr);
   }
   return result;
Index: generic/xotclDecls.h
===================================================================
diff -u -r044952af84b087821f5bd68570b84b8e3e000851 -rcde16e9d87173d7ef9179ce40e10c2f1f708940e
--- generic/xotclDecls.h	(.../xotclDecls.h)	(revision 044952af84b087821f5bd68570b84b8e3e000851)
+++ generic/xotclDecls.h	(.../xotclDecls.h)	(revision cde16e9d87173d7ef9179ce40e10c2f1f708940e)
@@ -40,7 +40,7 @@
 #ifndef XOTclGetObject_TCL_DECLARED
 #define XOTclGetObject_TCL_DECLARED
 /* 4 */
-EXTERN struct XOTcl_Object * XOTclGetObject (Tcl_Interp * interp,
+EXTERN struct XOTcl_Object * XOTclGetObject (Tcl_Interp * interp, 
 				char * name);
 #endif
 #ifndef XOTclGetClass_TCL_DECLARED
@@ -51,90 +51,90 @@
 #ifndef XOTclCreateObject_TCL_DECLARED
 #define XOTclCreateObject_TCL_DECLARED
 /* 6 */
-EXTERN int		XOTclCreateObject (Tcl_Interp * interp,
+EXTERN int		XOTclCreateObject (Tcl_Interp * interp, 
 				Tcl_Obj * name, struct XOTcl_Class * cl);
 #endif
 /* Slot 7 is reserved */
 #ifndef XOTclCreateClass_TCL_DECLARED
 #define XOTclCreateClass_TCL_DECLARED
 /* 8 */
-EXTERN int		XOTclCreateClass (Tcl_Interp * interp,
+EXTERN int		XOTclCreateClass (Tcl_Interp * interp, 
 				Tcl_Obj * name, struct XOTcl_Class * cl);
 #endif
 #ifndef XOTclDeleteObject_TCL_DECLARED
 #define XOTclDeleteObject_TCL_DECLARED
 /* 9 */
-EXTERN int		XOTclDeleteObject (Tcl_Interp * interp,
+EXTERN int		XOTclDeleteObject (Tcl_Interp * interp, 
 				struct XOTcl_Object * obj);
 #endif
 #ifndef XOTclDeleteClass_TCL_DECLARED
 #define XOTclDeleteClass_TCL_DECLARED
 /* 10 */
-EXTERN int		XOTclDeleteClass (Tcl_Interp * interp,
+EXTERN int		XOTclDeleteClass (Tcl_Interp * interp, 
 				struct XOTcl_Class * cl);
 #endif
 /* Slot 11 is reserved */
 /* Slot 12 is reserved */
 #ifndef XOTclRemovePMethod_TCL_DECLARED
 #define XOTclRemovePMethod_TCL_DECLARED
 /* 13 */
-EXTERN int		XOTclRemovePMethod (Tcl_Interp * interp,
+EXTERN int		XOTclRemovePMethod (Tcl_Interp * interp, 
 				struct XOTcl_Object * obj, char * nm);
 #endif
 #ifndef XOTclRemoveIMethod_TCL_DECLARED
 #define XOTclRemoveIMethod_TCL_DECLARED
 /* 14 */
-EXTERN int		XOTclRemoveIMethod (Tcl_Interp * interp,
+EXTERN int		XOTclRemoveIMethod (Tcl_Interp * interp, 
 				struct XOTcl_Class * cl, char * nm);
 #endif
 #ifndef XOTclOSetInstVar_TCL_DECLARED
 #define XOTclOSetInstVar_TCL_DECLARED
 /* 15 */
-EXTERN Tcl_Obj *	XOTclOSetInstVar (struct XOTcl_Object * obj,
-				Tcl_Interp * interp, Tcl_Obj * name,
+EXTERN Tcl_Obj *	XOTclOSetInstVar (struct XOTcl_Object * obj, 
+				Tcl_Interp * interp, Tcl_Obj * name, 
 				Tcl_Obj * value, int flgs);
 #endif
 #ifndef XOTclOGetInstVar_TCL_DECLARED
 #define XOTclOGetInstVar_TCL_DECLARED
 /* 16 */
-EXTERN Tcl_Obj *	XOTclOGetInstVar (struct XOTcl_Object * obj,
-				Tcl_Interp * interp, Tcl_Obj * name,
+EXTERN Tcl_Obj *	XOTclOGetInstVar (struct XOTcl_Object * obj, 
+				Tcl_Interp * interp, Tcl_Obj * name, 
 				int flgs);
 #endif
 #ifndef XOTclInstVar_TCL_DECLARED
 #define XOTclInstVar_TCL_DECLARED
 /* 17 */
-EXTERN int		XOTclInstVar (struct XOTcl_Object * obj,
-				Tcl_Interp * interp, char * name,
+EXTERN int		XOTclInstVar (struct XOTcl_Object * obj, 
+				Tcl_Interp * interp, char * name, 
 				char * destName);
 #endif
 /* Slot 18 is reserved */
 #ifndef XOTcl_ObjSetVar2_TCL_DECLARED
 #define XOTcl_ObjSetVar2_TCL_DECLARED
 /* 19 */
-EXTERN Tcl_Obj *	XOTcl_ObjSetVar2 (struct XOTcl_Object * obj,
-				Tcl_Interp * interp, Tcl_Obj * name1,
+EXTERN Tcl_Obj *	XOTcl_ObjSetVar2 (struct XOTcl_Object * obj, 
+				Tcl_Interp * interp, Tcl_Obj * name1, 
 				Tcl_Obj * name2, Tcl_Obj * value, int flgs);
 #endif
 #ifndef XOTcl_ObjGetVar2_TCL_DECLARED
 #define XOTcl_ObjGetVar2_TCL_DECLARED
 /* 20 */
-EXTERN Tcl_Obj *	XOTcl_ObjGetVar2 (struct XOTcl_Object * obj,
-				Tcl_Interp * interp, Tcl_Obj * name1,
+EXTERN Tcl_Obj *	XOTcl_ObjGetVar2 (struct XOTcl_Object * obj, 
+				Tcl_Interp * interp, Tcl_Obj * name1, 
 				Tcl_Obj * name2, int flgs);
 #endif
 #ifndef XOTclUnsetInstVar2_TCL_DECLARED
 #define XOTclUnsetInstVar2_TCL_DECLARED
 /* 21 */
-EXTERN int		XOTclUnsetInstVar2 (struct XOTcl_Object * obj,
-				Tcl_Interp * interp, char * name1,
+EXTERN int		XOTclUnsetInstVar2 (struct XOTcl_Object * obj, 
+				Tcl_Interp * interp, char * name1, 
 				char * name2, int flgs);
 #endif
 /* Slot 22 is reserved */
 #ifndef XOTclErrMsg_TCL_DECLARED
 #define XOTclErrMsg_TCL_DECLARED
 /* 23 */
-EXTERN int		XOTclErrMsg (Tcl_Interp * interp, char * msg,
+EXTERN int		XOTclErrMsg (Tcl_Interp * interp, char * msg, 
 				Tcl_FreeProc * type);
 #endif
 #ifndef XOTclVarErrMsg_TCL_DECLARED
@@ -145,21 +145,21 @@
 #ifndef XOTclErrInProc_TCL_DECLARED
 #define XOTclErrInProc_TCL_DECLARED
 /* 25 */
-EXTERN int		XOTclErrInProc (Tcl_Interp * interp,
-				Tcl_Obj * objName, Tcl_Obj * clName,
+EXTERN int		XOTclErrInProc (Tcl_Interp * interp, 
+				Tcl_Obj * objName, Tcl_Obj * clName, 
 				char * procName);
 #endif
 /* Slot 26 is reserved */
 #ifndef XOTclErrBadVal__TCL_DECLARED
 #define XOTclErrBadVal__TCL_DECLARED
 /* 27 */
-EXTERN int		XOTclErrBadVal_ (Tcl_Interp * interp,
+EXTERN int		XOTclErrBadVal_ (Tcl_Interp * interp, 
 				char * expected, char * value);
 #endif
 #ifndef XOTclObjErrType_TCL_DECLARED
 #define XOTclObjErrType_TCL_DECLARED
 /* 28 */
-EXTERN int		XOTclObjErrType (Tcl_Interp * interp, Tcl_Obj * nm,
+EXTERN int		XOTclObjErrType (Tcl_Interp * interp, Tcl_Obj * nm, 
 				char * wt);
 #endif
 #ifndef XOTclStackDump_TCL_DECLARED
@@ -176,7 +176,7 @@
 #ifndef XOTclSetObjClientData_TCL_DECLARED
 #define XOTclSetObjClientData_TCL_DECLARED
 /* 32 */
-EXTERN void		XOTclSetObjClientData (XOTcl_Object * obj,
+EXTERN void		XOTclSetObjClientData (XOTcl_Object * obj, 
 				ClientData data);
 #endif
 #ifndef XOTclGetObjClientData_TCL_DECLARED
@@ -187,7 +187,7 @@
 #ifndef XOTclSetClassClientData_TCL_DECLARED
 #define XOTclSetClassClientData_TCL_DECLARED
 /* 34 */
-EXTERN void		XOTclSetClassClientData (XOTcl_Class * cl,
+EXTERN void		XOTclSetClassClientData (XOTcl_Class * cl, 
 				ClientData data);
 #endif
 #ifndef XOTclGetClassClientData_TCL_DECLARED
@@ -198,67 +198,67 @@
 #ifndef XOTclRequireObjNamespace_TCL_DECLARED
 #define XOTclRequireObjNamespace_TCL_DECLARED
 /* 36 */
-EXTERN void		XOTclRequireObjNamespace (Tcl_Interp * interp,
+EXTERN void		XOTclRequireObjNamespace (Tcl_Interp * interp, 
 				XOTcl_Object * obj);
 #endif
 #ifndef XOTclErrBadVal_TCL_DECLARED
 #define XOTclErrBadVal_TCL_DECLARED
 /* 37 */
-EXTERN int		XOTclErrBadVal (Tcl_Interp * interp, char * context,
+EXTERN int		XOTclErrBadVal (Tcl_Interp * interp, char * context, 
 				char * expected, char * value);
 #endif
 #ifndef XOTclNextObjCmd_TCL_DECLARED
 #define XOTclNextObjCmd_TCL_DECLARED
 /* 38 */
-EXTERN int		XOTclNextObjCmd (ClientData cd, Tcl_Interp * interp,
+EXTERN int		XOTclNextObjCmd (ClientData cd, Tcl_Interp * interp, 
 				int objc, Tcl_Obj *CONST objv[]);
 #endif
 #ifndef XOTclCallMethodWithArgs_TCL_DECLARED
 #define XOTclCallMethodWithArgs_TCL_DECLARED
 /* 39 */
-EXTERN int		XOTclCallMethodWithArgs (ClientData cd,
-				Tcl_Interp * interp, Tcl_Obj * method,
-				Tcl_Obj * arg, int objc,
+EXTERN int		XOTclCallMethodWithArgs (ClientData cd, 
+				Tcl_Interp * interp, Tcl_Obj * method, 
+				Tcl_Obj * arg, int objc, 
 				Tcl_Obj *CONST objv[], int flags);
 #endif
 #ifndef XOTclObjErrArgCnt_TCL_DECLARED
 #define XOTclObjErrArgCnt_TCL_DECLARED
 /* 40 */
-EXTERN int		XOTclObjErrArgCnt (Tcl_Interp * interp,
-				Tcl_Obj * cmdName, Tcl_Obj * methodName,
+EXTERN int		XOTclObjErrArgCnt (Tcl_Interp * interp, 
+				Tcl_Obj * cmdName, Tcl_Obj * methodName, 
 				char * arglist);
 #endif
 #ifndef XOTclAddObjectMethod_TCL_DECLARED
 #define XOTclAddObjectMethod_TCL_DECLARED
 /* 41 */
-EXTERN int		XOTclAddObjectMethod (Tcl_Interp * interp,
-				struct XOTcl_Object * obj, CONST char * nm,
-				Tcl_ObjCmdProc * proc, ClientData cd,
+EXTERN int		XOTclAddObjectMethod (Tcl_Interp * interp, 
+				struct XOTcl_Object * obj, CONST char * nm, 
+				Tcl_ObjCmdProc * proc, ClientData cd, 
 				Tcl_CmdDeleteProc * dp, int flags);
 #endif
 #ifndef XOTclAddInstanceMethod_TCL_DECLARED
 #define XOTclAddInstanceMethod_TCL_DECLARED
 /* 42 */
-EXTERN int		XOTclAddInstanceMethod (Tcl_Interp * interp,
-				struct XOTcl_Class * cl, CONST char * nm,
-				Tcl_ObjCmdProc * proc, ClientData cd,
+EXTERN int		XOTclAddInstanceMethod (Tcl_Interp * interp, 
+				struct XOTcl_Class * cl, CONST char * nm, 
+				Tcl_ObjCmdProc * proc, ClientData cd, 
 				Tcl_CmdDeleteProc * dp, int flags);
 #endif
 #ifndef XOTclCreate_TCL_DECLARED
 #define XOTclCreate_TCL_DECLARED
 /* 43 */
-EXTERN int		XOTclCreate (Tcl_Interp * in, XOTcl_Class * class,
-				Tcl_Obj * name, ClientData data, int objc,
+EXTERN int		XOTclCreate (Tcl_Interp * in, XOTcl_Class * class, 
+				Tcl_Obj * name, ClientData data, int objc, 
 				Tcl_Obj *CONST objv[]);
 #endif
 
 typedef struct XotclStubHooks {
-    const struct XotclIntStubs *xotclIntStubs;
+    struct XotclIntStubs *xotclIntStubs;
 } XotclStubHooks;
 
 typedef struct XotclStubs {
     int magic;
-    const struct XotclStubHooks *hooks;
+    struct XotclStubHooks *hooks;
 
     int (*xotcl_Init) (Tcl_Interp * interp); /* 0 */
     void *reserved1;
@@ -306,9 +306,13 @@
     int (*xOTclCreate) (Tcl_Interp * in, XOTcl_Class * class, Tcl_Obj * name, ClientData data, int objc, Tcl_Obj *CONST objv[]); /* 43 */
 } XotclStubs;
 
-#if defined(USE_XOTCL_STUBS) && !defined(USE_XOTCL_STUB_PROCS)
-extern const XotclStubs *xotclStubsPtr;
-#endif /* defined(USE_XOTCL_STUBS) && !defined(USE_XOTCL_STUB_PROCS) */
+#ifdef __cplusplus
+extern "C" {
+#endif
+extern XotclStubs *xotclStubsPtr;
+#ifdef __cplusplus
+}
+#endif
 
 #if defined(USE_XOTCL_STUBS) && !defined(USE_XOTCL_STUB_PROCS)
 
Index: generic/xotclInt.h
===================================================================
diff -u -rd4e66214fc3323aea509676709c9b7ace64f0f50 -rcde16e9d87173d7ef9179ce40e10c2f1f708940e
--- generic/xotclInt.h	(.../xotclInt.h)	(revision d4e66214fc3323aea509676709c9b7ace64f0f50)
+++ generic/xotclInt.h	(.../xotclInt.h)	(revision cde16e9d87173d7ef9179ce40e10c2f1f708940e)
@@ -256,26 +256,31 @@
      /*fprintf(stderr,"PUSH CMETHOD_FRAME (XOTcl_PushFrame) frame %p\n",framePtr);*/ \
      if ((obj)->nsPtr) { \
        frame_constructed = 0; \
-       /*fprintf(stderr,"XOTcl_PushFrame frame %p\n",framePtr);*/ \
+       /*fprintf(stderr,"XOTcl_PushFrame frame %p nsPtr %p obj %p\n",framePtr,(obj)->nsPtr,obj);*/ \
+       assert(obj == csc->self); \
        Tcl_PushCallFrame(interp, (Tcl_CallFrame*)framePtr, (obj)->nsPtr, 0|FRAME_IS_XOTCL_CMETHOD); \
+       assert(obj == csc->self); \
      } else { \
-       /*fprintf(stderr,"XOTcl_PushFrame frame %p (with fakeProc)\n",framePtr);*/ \
+       /*fprintf(stderr,"XOTcl_PushFrame frame %p (with fakeProc) obj %p\n",framePtr,obj);*/ \
+       assert(obj == csc->self); \
        Tcl_PushCallFrame(interp, (Tcl_CallFrame*)framePtr, Tcl_CallFrame_nsPtr(Tcl_Interp_varFramePtr(interp)), 1|FRAME_IS_XOTCL_CMETHOD); \
+       assert(obj == csc->self); \
        Tcl_CallFrame_procPtr(framePtr) = &RUNTIME_STATE(interp)->fakeProc; \
        Tcl_CallFrame_varTablePtr(framePtr) = (obj)->varTable;	\
      } \
      XOTcl_PushFrameSetCd(csc)
 
+
 #define XOTcl_PopFrame(interp,obj) \
      if (!(obj)->nsPtr && ((obj)->varTable == 0)) {        \
          (obj)->varTable = Tcl_CallFrame_varTablePtr(framePtr); \
      } \
-     if (frame_constructed) {                                         \
-       Tcl_CallFrame_varTablePtr(Tcl_Interp_framePtr(interp)) = 0;                        \
-       /*Tcl_CallFrame_procPtr(myFramePtr) = 0;                  */       \
-       }                                                               \
+     if (frame_constructed) { \
+       Tcl_CallFrame_varTablePtr(Tcl_Interp_framePtr(interp)) = 0; \
+       /*Tcl_CallFrame_procPtr(myFramePtr) = 0; */ \
+     } \
      /*fprintf(stderr,"POP  OBJECT_FRAME (XOTcl_PopFrame) frame %p\n",framePtr);*/ \
-     Tcl_PopCallFrame(interp)
+    Tcl_PopCallFrame(interp)
 
 #if 0
 #define XOTcl_SimplePopFrame(interp,obj) \
Index: generic/xotclIntDecls.h
===================================================================
diff -u -r044952af84b087821f5bd68570b84b8e3e000851 -rcde16e9d87173d7ef9179ce40e10c2f1f708940e
--- generic/xotclIntDecls.h	(.../xotclIntDecls.h)	(revision 044952af84b087821f5bd68570b84b8e3e000851)
+++ generic/xotclIntDecls.h	(.../xotclIntDecls.h)	(revision cde16e9d87173d7ef9179ce40e10c2f1f708940e)
@@ -31,13 +31,17 @@
 
 typedef struct XotclIntStubs {
     int magic;
-    const struct XotclIntStubHooks *hooks;
+    struct XotclIntStubHooks *hooks;
 
 } XotclIntStubs;
 
-#if defined(USE_XOTCL_STUBS) && !defined(USE_XOTCL_STUB_PROCS)
-extern const XotclIntStubs *xotclIntStubsPtr;
-#endif /* defined(USE_XOTCL_STUBS) && !defined(USE_XOTCL_STUB_PROCS) */
+#ifdef __cplusplus
+extern "C" {
+#endif
+extern XotclIntStubs *xotclIntStubsPtr;
+#ifdef __cplusplus
+}
+#endif
 
 #if defined(USE_XOTCL_STUBS) && !defined(USE_XOTCL_STUB_PROCS)
 
Index: generic/xotclStubInit.c
===================================================================
diff -u -r044952af84b087821f5bd68570b84b8e3e000851 -rcde16e9d87173d7ef9179ce40e10c2f1f708940e
--- generic/xotclStubInit.c	(.../xotclStubInit.c)	(revision 044952af84b087821f5bd68570b84b8e3e000851)
+++ generic/xotclStubInit.c	(.../xotclStubInit.c)	(revision cde16e9d87173d7ef9179ce40e10c2f1f708940e)
@@ -24,16 +24,16 @@
 
 /* !BEGIN!: Do not edit below this line. */
 
-static const XotclIntStubs xotclIntStubs = {
+XotclIntStubs xotclIntStubs = {
     TCL_STUB_MAGIC,
     NULL,
 };
 
-static const XotclStubHooks xotclStubHooks = {
+static XotclStubHooks xotclStubHooks = {
     &xotclIntStubs
 };
 
-static const XotclStubs xotclStubs = {
+XotclStubs xotclStubs = {
     TCL_STUB_MAGIC,
     &xotclStubHooks,
     Xotcl_Init, /* 0 */