Index: TODO
===================================================================
diff -u -ra0faba200038c44cda56f3f421361563b4bd95d7 -re367957430bf9246069791785619a5503e166d33
--- TODO	(.../TODO)	(revision a0faba200038c44cda56f3f421361563b4bd95d7)
+++ TODO	(.../TODO)	(revision e367957430bf9246069791785619a5503e166d33)
@@ -5746,6 +5746,16 @@
 - extended regression test
 - bump version number to 2.1
 
+
+- make use of Tcl_SaveInterpState() and friends for saving results
+  in NsfDStringEval()
+- added results in debug exit calls
+- changed interface of NsfDStringEval to control behavior via bitflags
+  (this is after all more readable than a argument list of "0" and "1"s)
+- added optional recursion prevention for functions called via NsfDStringEval
+  (handling NSF_EVAL_DEBUG, NSF_EVAL_LOG, NSF_EVAL_DEPRECATED)
+- added regression tests for potential recursive calls
+
 ========================================================================
 TODO:
 - add regression tests for debug and deprecated in methods (behavior)
Index: generic/nsf.c
===================================================================
diff -u -rfd0f246e04ac2b64f1802dfd265bfc588e496c21 -re367957430bf9246069791785619a5503e166d33
--- generic/nsf.c	(.../nsf.c)	(revision fd0f246e04ac2b64f1802dfd265bfc588e496c21)
+++ generic/nsf.c	(.../nsf.c)	(revision e367957430bf9246069791785619a5503e166d33)
@@ -510,38 +510,63 @@
  *----------------------------------------------------------------------
  */
 int
-NsfDStringEval(Tcl_Interp *interp, Tcl_DString *dsPtr, const char *context, int safe, int noProfile) {
-  int result, prevProfileSetting;
-  Tcl_Obj *savedResultObj;
+NsfDStringEval(Tcl_Interp *interp, Tcl_DString *dsPtr, const char *context,
+               unsigned int traceEvalFlags) {
+  Tcl_InterpState  state;
+  NsfRuntimeState *rst;
+  int              result, prevDoProfile;
 
   nonnull_assert(interp != NULL);
   nonnull_assert(dsPtr != NULL);
   nonnull_assert(context != NULL);
 
-  if (noProfile) {
-    prevProfileSetting = RUNTIME_STATE(interp)->doProfile;
-    RUNTIME_STATE(interp)->doProfile = 0;
+  rst = RUNTIME_STATE(interp);
+
+  if ((traceEvalFlags & NSF_EVAL_PREVENT_RECURSION) != 0u) {
+    /*
+     * We do not want to debug the debug statements, since this would cause an
+     * inifinite recursion.  Check, if we allow execution of the eval call.
+     */
+    if ((rst->preventRecursionFlags & traceEvalFlags) != 0) {
+      /*
+       * Recursive case, do NOT execute the cmd and return silently.
+       */
+      return TCL_OK;
+    }
+
+    rst->preventRecursionFlags |= traceEvalFlags;
   }
 
-  if (safe) {
-    savedResultObj = Tcl_GetObjResult(interp);
-    INCR_REF_COUNT(savedResultObj);
+  if ((traceEvalFlags & NSF_EVAL_NOPROFILE) && rst->doProfile == 1) {
+    /*
+     * Profiling should be deactivated for the eval.
+     */
+    prevDoProfile = 1;
+    rst->doProfile = 0;
+  } else {
+    prevDoProfile = 0;
   }
-  result = Tcl_EvalEx(interp, Tcl_DStringValue(dsPtr), Tcl_DStringLength(dsPtr), 0);
 
-  if (safe) {
-    if (result == TCL_OK) {
-      Tcl_SetObjResult(interp, savedResultObj);
-    }
-    DECR_REF_COUNT(savedResultObj);
+  if ((traceEvalFlags & NSF_EVAL_SAVE) != 0u) {
+    state = Tcl_SaveInterpState(interp, TCL_OK);
   }
-  if (noProfile) {
-    RUNTIME_STATE(interp)->doProfile = prevProfileSetting;
-  }
+  result = Tcl_EvalEx(interp, Tcl_DStringValue(dsPtr), Tcl_DStringLength(dsPtr), 0);
 
   if (unlikely(result == TCL_ERROR)) {
     NsfErrorContext(interp, context);
   }
+
+  if ((traceEvalFlags & NSF_EVAL_SAVE) != 0u) {
+    Tcl_RestoreInterpState(interp, state);
+  }
+  if ((traceEvalFlags & NSF_EVAL_PREVENT_RECURSION) != 0u) {
+    rst->preventRecursionFlags &= ~traceEvalFlags;
+  }
+
+  if (prevDoProfile == 1) {
+    rst->doProfile = 1;
+  }
+
   return result;
 }
 
@@ -588,7 +613,7 @@
     Tcl_DStringAppendElement(&cmdString, "::nsf::log");
     Tcl_DStringAppendElement(&cmdString, level);
     Tcl_DStringAppendElement(&cmdString, Tcl_DStringValue(&ds));
-    NsfDStringEval(interp, &cmdString, "log command", 0, 0);
+    NsfDStringEval(interp, &cmdString, "log command", (NSF_EVAL_LOG|NSF_EVAL_NOPROFILE));
     Tcl_DStringFree(&cmdString);
     Tcl_DStringFree(&ds);
   }
@@ -629,7 +654,7 @@
   Tcl_DStringAppendElement(dsPtr, oldCmd);
   Tcl_DStringAppendElement(dsPtr, newCmd);
 
-  NsfDStringEval(interp, dsPtr, "log command", 0, 1);
+  NsfDStringEval(interp, dsPtr, "deprecated command", (NSF_EVAL_DEPRECATED|NSF_EVAL_NOPROFILE));
 
   Tcl_DStringFree(dsPtr);
 }
Index: generic/nsfInt.h
===================================================================
diff -u -ra0faba200038c44cda56f3f421361563b4bd95d7 -re367957430bf9246069791785619a5503e166d33
--- generic/nsfInt.h	(.../nsfInt.h)	(revision a0faba200038c44cda56f3f421361563b4bd95d7)
+++ generic/nsfInt.h	(.../nsfInt.h)	(revision e367957430bf9246069791785619a5503e166d33)
@@ -450,7 +450,19 @@
 #define NSF_CMD_CLASS_ONLY_METHOD		0x00100000
 #define NSF_CMD_DEPRECATED_METHOD		0x00200000
 #define NSF_CMD_DEBUG_METHOD			0x00400000
+
 /*
+ * traceEvalFlags controlling NsfDStringEval
+ */
+#define NSF_EVAL_SAVE                    0x01u  /* save interp context */
+#define NSF_EVAL_NOPROFILE               0x02u  /* no profile below this call */
+#define NSF_EVAL_DEBUG                   0x04u  /* call is a debug call, prevent recursion */
+#define NSF_EVAL_LOG                     0x08u  /* call is a log call, prevent recursion */
+#define NSF_EVAL_DEPRECATED              0x10u  /* call is a deprecated call, prevent recursion */
+
+#define NSF_EVAL_PREVENT_RECURSION (NSF_EVAL_DEBUG|NSF_EVAL_LOG|NSF_EVAL_DEPRECATED)
+
+/*
  * object flags ...
  */
 
@@ -933,6 +945,7 @@
   int doKeepcmds;
   int doProfile;
   int doTrace;
+  unsigned int preventRecursionFlags;
   int doSoftrecreate;
   /* keep track of defined filters */
   Tcl_HashTable activeFilterTablePtr;
@@ -1127,7 +1140,8 @@
 				  const char *methodName)
   nonnull(1) nonnull(3) returns_nonnull;
 
-EXTERN int NsfDStringEval(Tcl_Interp *interp, Tcl_DString *dsPtr, const char *context, int safe, int noProfile)
+EXTERN int NsfDStringEval(Tcl_Interp *interp, Tcl_DString *dsPtr, const char *context,
+			  unsigned int traceEvalFlags)
   nonnull(1) nonnull(2) nonnull(3);
 
 
Index: generic/nsfProfile.c
===================================================================
diff -u -r2771c4c7e0b56fe2a6cde84fdae9b170ff652928 -re367957430bf9246069791785619a5503e166d33
--- generic/nsfProfile.c	(.../nsfProfile.c)	(revision 2771c4c7e0b56fe2a6cde84fdae9b170ff652928)
+++ generic/nsfProfile.c	(.../nsfProfile.c)	(revision e367957430bf9246069791785619a5503e166d33)
@@ -169,7 +169,7 @@
   Nsf_DStringPrintf(&ds, " {%s}", ObjStr(listObj));
   DECR_REF_COUNT(listObj);
 
-  NsfDStringEval(interp, &ds, "debug call", 1, 1);
+  NsfDStringEval(interp, &ds, "debug call", (NSF_EVAL_DEBUG|NSF_EVAL_SAVE|NSF_EVAL_NOPROFILE));
 
   Tcl_DStringFree(&ds);
 
@@ -205,7 +205,7 @@
     Tcl_DStringAppend(dsPtr, " {}", 4);
   }
 
-  NsfDStringEval(interp, &ds, "debug exit", 1, 1);
+  NsfDStringEval(interp, &ds, "debug exit", (NSF_EVAL_DEBUG|NSF_EVAL_SAVE|NSF_EVAL_NOPROFILE));
 
   Tcl_DStringFree(dsPtr);
   rst->debugCallingDepth--;
Index: generic/nsfStack.c
===================================================================
diff -u -r8854eeff1e1b2d5fde52ee4f71b1e2b7844b2dea -re367957430bf9246069791785619a5503e166d33
--- generic/nsfStack.c	(.../nsfStack.c)	(revision 8854eeff1e1b2d5fde52ee4f71b1e2b7844b2dea)
+++ generic/nsfStack.c	(.../nsfStack.c)	(revision e367957430bf9246069791785619a5503e166d33)
@@ -1232,9 +1232,11 @@
 
     if ((Tcl_Command_flags(cscPtr->cmdPtr) & NSF_CMD_DEBUG_METHOD) != 0) {
 #if defined(NSF_PROFILE) || defined(NSF_DTRACE)
-      NsfProfileDebugExit(interp, cscPtr->self, cscPtr->cl, cscPtr->methodName, cscPtr->startSec, cscPtr->startUsec);
+      NsfProfileDebugExit(interp, cscPtr->self, cscPtr->cl, cscPtr->methodName,
+                          cscPtr->startSec, cscPtr->startUsec);
 #else
-      NsfProfileDebugExit(interp, cscPtr->self, cscPtr->cl, Tcl_GetCommandName(interp, cscPtr->cmdPtr), 0, 0);
+      NsfProfileDebugExit(interp, cscPtr->self, cscPtr->cl,
+                          Tcl_GetCommandName(interp, cscPtr->cmdPtr), 0, 0);
 #endif
     }
 
@@ -1262,6 +1264,7 @@
      */
     if (unlikely(cscPtr->cl != NULL)) {
       NsfObject *clObject = &cscPtr->cl->object;
+
       clObject->activationCount --;
       MEM_COUNT_FREE("class.activationCount", clObject);
 
Index: tests/nsf-cmd.test
===================================================================
diff -u -ra775d31c0b4770cc7eddc1b4c015bc0dea1fddd2 -re367957430bf9246069791785619a5503e166d33
--- tests/nsf-cmd.test	(.../nsf-cmd.test)	(revision a775d31c0b4770cc7eddc1b4c015bc0dea1fddd2)
+++ tests/nsf-cmd.test	(.../nsf-cmd.test)	(revision e367957430bf9246069791785619a5503e166d33)
@@ -277,7 +277,34 @@
 
 }
 
+#
+# test error transparency of "-debug" option
+#
+nx::test case nsf-debug-error {
+  nsf::proc foo {} {
+    set exception [catch {bar} errorMsg options]
+    if {$exception} {
+      puts stderr O=$options
+      puts stderr <<$::errorInfo>>
+      set result [list $exception $errorMsg [string length $::errorInfo] $::errorCode]
+    } else {
+      set result ""
+    }
+    return $result
+  }
+  nsf::proc bar {} {return -code error -errorcode MyException "exception"}
 
+  ? {foo} {1 exception 35 MyException}
+
+  #
+  # redefine bar with debug flag
+  #
+  nsf::proc -debug bar {} {return -code error -errorcode MyException "exception"}
+
+  ? {foo} {1 exception 35 MyException}
+}
+
+
 #
 # test virtual arg resolution + filtering
 #
@@ -384,6 +411,83 @@
 }
 
 #
+# recursive debug calls
+#
+nx::test case nsf-debug-recursive {
+  set ::count 0
+
+  set oldCall [nsf::cmd::info definition ::nsf::debug::call]
+  nsf::proc -debug ::nsf::debug::call args {
+    incr ::count
+    #puts "MYDEBUG $args"
+  }
+  nsf::proc -debug foo {} {return 1}
+
+  ? {foo} "1"
+  ? {set ::count} 1
+
+  # restore original definition of ::nsf::debug::call
+  eval $oldCall
+}
+
+#
+# recursive log calls
+#
+nx::test case nsf-log-recursive {
+
+  #
+  # First the case, where the log function calls another Tcl function
+  # (which might be debugged)
+  #
+  set oldCall [nsf::cmd::info definition ::nsf::log]
+  nsf::proc ::nsf::log args {
+    incr ::count
+    #puts "::nsf::log <$args> ... before foo"
+    foo
+    #puts "::nsf::log <$args> ... after foo"
+    return
+  }
+  nsf::proc foo {} {return 1}
+  nsf::proc bar {} {nsf::log notice hello}
+
+  #
+  # "foo" calls no nsf::log, but "bar" calls it once
+  #
+  set ::count 0
+  ? {foo} "1"
+  ? {set ::count} 0
+
+  set ::count 0
+  ? {bar} ""
+  ? {set ::count} 1
+
+  #
+  # now we add the debug flag to foo, therefore "foo" will call
+  # "nsf::log", which might become a infinite recursion loop.
+  #
+  nsf::proc -debug foo {} {return 1}
+
+  #
+  # "foo" is has now "-debug" set, therefore it calls the log function
+  #
+  set ::count 0
+  ? {foo} "1"
+  ? {set ::count} 2
+
+  #
+  # "bar" calls "log", which in turn calls a debugged function
+  #
+  set ::count 0
+  ? {bar} ""
+  ? {set ::count} 3
+
+  # restore original definition of ::nsf::log
+  eval $oldCall
+
+}
+
+
+#
 # Local variables:
 #    mode: tcl
 #    tcl-indent-level: 2