Proposed fix for [534172ff5b]: Crash in DeleteReflectedChannelMap (in…

…troduced via tcllib 1.21)

generic/tclIORChan.c

@@ -1128,8 +1128,8 @@ ReflectClose(
 	/*
 	 * This call comes from TclFinalizeIOSystem. There are no
 	 * interpreters, and therefore we cannot call upon the handler command
-	 * anymore. Threading is irrelevant as well. We simply clean up all
-	 * our C level data structures and leave the Tcl level to the other
+	 * anymore. Threading is irrelevant as well. Simply clean up all
+	 * the C level data structures and leave the Tcl level to the other
 	 * finalization functions.
 	 */
 
@@ -2697,6 +2697,7 @@ DeleteThreadReflectedChannelMap(
     Tcl_ThreadId self = Tcl_GetCurrentThread();
     ReflectedChannelMap *rcmPtr; /* The map */
     ForwardingResult *resultPtr;
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
     (void)dummy;
 
     /*
@@ -2777,6 +2778,7 @@ DeleteThreadReflectedChannelMap(
      */
 
     rcmPtr = GetThreadReflectedChannelMap();
+    tsdPtr->rcmPtr = NULL;
     for (hPtr = Tcl_FirstHashEntry(&rcmPtr->map, &hSearch);
 	    hPtr != NULL;
 	    hPtr = Tcl_FirstHashEntry(&rcmPtr->map, &hSearch)) {
@@ -3083,10 +3085,10 @@ ForwardProc(
                 (paramPtr->seek.seekMode==SEEK_SET) ? "start" :
                 (paramPtr->seek.seekMode==SEEK_CUR) ? "current" : "end", -1);
 
-        Tcl_IncrRefCount(offObj);
-        Tcl_IncrRefCount(baseObj);
+	Tcl_IncrRefCount(offObj);
+	Tcl_IncrRefCount(baseObj);
 
-        Tcl_Preserve(rcPtr);
+	Tcl_Preserve(rcPtr);
 	if (InvokeTclMethod(rcPtr, METH_SEEK, offObj, baseObj, &resObj)!=TCL_OK){
 	    ForwardSetObjError(paramPtr, resObj);
 	    paramPtr->seek.offset = -1;