[Bug 3386721] Allow multiple [load]ing of the Tcltest package

2 files changed, 109 insertions, 62 deletions

diff --git a/ChangeLog b/ChangeLog
index bdf73e9..127ee0b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2011-08-10 Alexandre Ferrieux  <ferrieux@users.sourceforge.net>
+
+	* generic/tclTestObj.c: [Bug 3386721] Allow multiple [load]ing of
+	the Tcltest package
+
 2011-08-09 Alexandre Ferrieux  <ferrieux@users.sourceforge.net>
 
 	* generic/tclBasic.c: [Bug 2919042] Restore "valgrindability" of Tcl
diff --git a/generic/tclTestObj.c b/generic/tclTestObj.c
index 92c278f..7494beb 100644
--- a/generic/tclTestObj.c
+++ b/generic/tclTestObj.c
@@ -20,23 +20,15 @@
 #include "tclInt.h"
 #include "tommath.h"
 
-/*
- * An array of Tcl_Obj pointers used in the commands that operate on or get
- * the values of Tcl object-valued variables. varPtr[i] is the i-th variable's
- * Tcl_Obj *.
- */
-
-#define NUMBER_OF_OBJECT_VARS 20
-static Tcl_Obj *varPtr[NUMBER_OF_OBJECT_VARS];
 
 /*
  * Forward declarations for functions defined later in this file:
  */
 
-static int		CheckIfVarUnset(Tcl_Interp *interp, int varIndex);
+static int		CheckIfVarUnset(Tcl_Interp *interp, Tcl_Obj **varPtr, int varIndex);
 static int		GetVariableIndex(Tcl_Interp *interp,
 			    const char *string, int *indexPtr);
-static void		SetVarToObj(int varIndex, Tcl_Obj *objPtr);
+static void		SetVarToObj(Tcl_Obj **varPtr, int varIndex, Tcl_Obj *objPtr);
 static int		TestbignumobjCmd(ClientData dummy, Tcl_Interp *interp,
 			    int objc, Tcl_Obj *const objv[]);
 static int		TestbooleanobjCmd(ClientData dummy,
@@ -62,6 +54,27 @@ typedef struct TestString {
     Tcl_UniChar unicode[2];
 } TestString;
 
+#define VARPTR_KEY "TCLOBJTEST_VARPTR"
+#define NUMBER_OF_OBJECT_VARS 20
+
+static void VarPtrDeleteProc(ClientData clientData, Tcl_Interp *interp)
+{
+    register int i;
+    Tcl_Obj **varPtr = (Tcl_Obj **) clientData;
+    for (i = 0;  i < NUMBER_OF_OBJECT_VARS;  i++) {
+	if (varPtr[i]) Tcl_DecrRefCount(varPtr[i]);
+    }
+    Tcl_DeleteAssocData(interp, VARPTR_KEY);
+    ckfree(varPtr);
+}
+
+static Tcl_Obj **GetVarPtr(Tcl_Interp *interp)
+{
+    Tcl_InterpDeleteProc *proc;
+
+    return (Tcl_Obj **) Tcl_GetAssocData(interp, VARPTR_KEY, &proc);
+}
+
 /*
  *----------------------------------------------------------------------
  *
@@ -85,7 +98,18 @@ TclObjTest_Init(
     Tcl_Interp *interp)
 {
     register int i;
+    /*
+     * An array of Tcl_Obj pointers used in the commands that operate on or get
+     * the values of Tcl object-valued variables. varPtr[i] is the i-th variable's
+     * Tcl_Obj *.
+     */
+    Tcl_Obj **varPtr;
 
+    varPtr = (Tcl_Obj **) ckalloc(NUMBER_OF_OBJECT_VARS *sizeof(varPtr[0]));
+    if (!varPtr) {
+	return TCL_ERROR;
+    }
+    Tcl_SetAssocData(interp, VARPTR_KEY, VarPtrDeleteProc, varPtr);
     for (i = 0;  i < NUMBER_OF_OBJECT_VARS;  i++) {
 	varPtr[i] = NULL;
     }
@@ -142,6 +166,7 @@ TestbignumobjCmd(
     int index, varIndex;
     const char *string;
     mp_int bignumValue, newValue;
+    Tcl_Obj **varPtr;
 
     if (objc < 3) {
 	Tcl_WrongNumArgs(interp, 1, objv, "option ?arg ...?");
@@ -155,6 +180,7 @@ TestbignumobjCmd(
     if (GetVariableIndex(interp, string, &varIndex) != TCL_OK) {
 	return TCL_ERROR;
     }
+    varPtr = GetVarPtr(interp);
 
     switch (index) {
     case BIGNUM_SET:
@@ -186,7 +212,7 @@ TestbignumobjCmd(
 	if ((varPtr[varIndex] != NULL) && !Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetBignumObj(varPtr[varIndex], &bignumValue);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewBignumObj(&bignumValue));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewBignumObj(&bignumValue));
 	}
 	break;
 
@@ -195,7 +221,7 @@ TestbignumobjCmd(
 	    Tcl_WrongNumArgs(interp, 2, objv, "varIndex");
 	    return TCL_ERROR;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	break;
@@ -205,7 +231,7 @@ TestbignumobjCmd(
 	    Tcl_WrongNumArgs(interp, 2, objv, "varIndex");
 	    return TCL_ERROR;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	if (Tcl_GetBignumFromObj(interp, varPtr[varIndex],
@@ -224,7 +250,7 @@ TestbignumobjCmd(
 	if (!Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetBignumObj(varPtr[varIndex], &newValue);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewBignumObj(&newValue));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewBignumObj(&newValue));
 	}
 	break;
 
@@ -233,7 +259,7 @@ TestbignumobjCmd(
 	    Tcl_WrongNumArgs(interp, 2, objv, "varIndex");
 	    return TCL_ERROR;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	if (Tcl_GetBignumFromObj(interp, varPtr[varIndex],
@@ -252,7 +278,7 @@ TestbignumobjCmd(
 	if (!Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetBignumObj(varPtr[varIndex], &newValue);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewBignumObj(&newValue));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewBignumObj(&newValue));
 	}
     }
 
@@ -287,6 +313,7 @@ TestbooleanobjCmd(
 {
     int varIndex, boolValue;
     const char *index, *subCmd;
+    Tcl_Obj **varPtr;
 
     if (objc < 3) {
 	wrongNumArgs:
@@ -299,6 +326,8 @@ TestbooleanobjCmd(
 	return TCL_ERROR;
     }
 
+    varPtr = GetVarPtr(interp);
+
     subCmd = Tcl_GetString(objv[1]);
     if (strcmp(subCmd, "set") == 0) {
 	if (objc != 4) {
@@ -319,14 +348,14 @@ TestbooleanobjCmd(
 	if ((varPtr[varIndex] != NULL) && !Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetBooleanObj(varPtr[varIndex], boolValue);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewBooleanObj(boolValue));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewBooleanObj(boolValue));
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
     } else if (strcmp(subCmd, "get") == 0) {
 	if (objc != 3) {
 	    goto wrongNumArgs;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
@@ -334,7 +363,7 @@ TestbooleanobjCmd(
 	if (objc != 3) {
 	    goto wrongNumArgs;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	if (Tcl_GetBooleanFromObj(interp, varPtr[varIndex],
@@ -344,7 +373,7 @@ TestbooleanobjCmd(
 	if (!Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetBooleanObj(varPtr[varIndex], !boolValue);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewBooleanObj(!boolValue));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewBooleanObj(!boolValue));
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
     } else {
@@ -385,6 +414,7 @@ TestdoubleobjCmd(
     int varIndex;
     double doubleValue;
     const char *index, *subCmd, *string;
+    Tcl_Obj **varPtr;
 
     if (objc < 3) {
 	wrongNumArgs:
@@ -392,6 +422,8 @@ TestdoubleobjCmd(
 	return TCL_ERROR;
     }
 
+    varPtr = GetVarPtr(interp);
+
     index = Tcl_GetString(objv[2]);
     if (GetVariableIndex(interp, index, &varIndex) != TCL_OK) {
 	return TCL_ERROR;
@@ -418,14 +450,14 @@ TestdoubleobjCmd(
 	if ((varPtr[varIndex] != NULL) && !Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetDoubleObj(varPtr[varIndex], doubleValue);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewDoubleObj(doubleValue));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewDoubleObj(doubleValue));
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
     } else if (strcmp(subCmd, "get") == 0) {
 	if (objc != 3) {
 	    goto wrongNumArgs;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
@@ -433,7 +465,7 @@ TestdoubleobjCmd(
 	if (objc != 3) {
 	    goto wrongNumArgs;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	if (Tcl_GetDoubleFromObj(interp, varPtr[varIndex],
@@ -443,14 +475,14 @@ TestdoubleobjCmd(
 	if (!Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetDoubleObj(varPtr[varIndex], doubleValue * 10.0);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewDoubleObj(doubleValue * 10.0));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewDoubleObj(doubleValue * 10.0));
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
     } else if (strcmp(subCmd, "div10") == 0) {
 	if (objc != 3) {
 	    goto wrongNumArgs;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	if (Tcl_GetDoubleFromObj(interp, varPtr[varIndex],
@@ -460,7 +492,7 @@ TestdoubleobjCmd(
 	if (!Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetDoubleObj(varPtr[varIndex], doubleValue / 10.0);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewDoubleObj(doubleValue / 10.0));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewDoubleObj(doubleValue / 10.0));
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
     } else {
@@ -603,6 +635,7 @@ TestintobjCmd(
     int intValue, varIndex, i;
     long longValue;
     const char *index, *subCmd, *string;
+    Tcl_Obj **varPtr;
 
     if (objc < 3) {
 	wrongNumArgs:
@@ -610,6 +643,7 @@ TestintobjCmd(
 	return TCL_ERROR;
     }
 
+    varPtr = GetVarPtr(interp);
     index = Tcl_GetString(objv[2]);
     if (GetVariableIndex(interp, index, &varIndex) != TCL_OK) {
 	return TCL_ERROR;
@@ -637,7 +671,7 @@ TestintobjCmd(
 	if ((varPtr[varIndex] != NULL) && !Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetIntObj(varPtr[varIndex], intValue);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewIntObj(intValue));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewIntObj(intValue));
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
     } else if (strcmp(subCmd, "set2") == 0) { /* doesn't set result */
@@ -652,7 +686,7 @@ TestintobjCmd(
 	if ((varPtr[varIndex] != NULL) && !Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetIntObj(varPtr[varIndex], intValue);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewIntObj(intValue));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewIntObj(intValue));
 	}
     } else if (strcmp(subCmd, "setlong") == 0) {
 	if (objc != 4) {
@@ -666,7 +700,7 @@ TestintobjCmd(
 	if ((varPtr[varIndex] != NULL) && !Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetLongObj(varPtr[varIndex], intValue);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewLongObj(intValue));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewLongObj(intValue));
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
     } else if (strcmp(subCmd, "setmaxlong") == 0) {
@@ -677,13 +711,13 @@ TestintobjCmd(
 	if ((varPtr[varIndex] != NULL) && !Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetLongObj(varPtr[varIndex], maxLong);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewLongObj(maxLong));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewLongObj(maxLong));
 	}
     } else if (strcmp(subCmd, "ismaxlong") == 0) {
 	if (objc != 3) {
 	    goto wrongNumArgs;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	if (Tcl_GetLongFromObj(interp, varPtr[varIndex], &longValue) != TCL_OK) {
@@ -695,7 +729,7 @@ TestintobjCmd(
 	if (objc != 3) {
 	    goto wrongNumArgs;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
@@ -703,7 +737,7 @@ TestintobjCmd(
 	if (objc != 3) {
 	    goto wrongNumArgs;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	string = Tcl_GetString(varPtr[varIndex]);
@@ -725,7 +759,7 @@ TestintobjCmd(
 	if ((varPtr[varIndex] != NULL) && !Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetLongObj(varPtr[varIndex], LONG_MAX);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewLongObj(LONG_MAX));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewLongObj(LONG_MAX));
 	}
 	if (Tcl_GetIntFromObj(interp, varPtr[varIndex], &i) != TCL_OK) {
 	    Tcl_ResetResult(interp);
@@ -738,7 +772,7 @@ TestintobjCmd(
 	if (objc != 3) {
 	    goto wrongNumArgs;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	if (Tcl_GetIntFromObj(interp, varPtr[varIndex],
@@ -748,14 +782,14 @@ TestintobjCmd(
 	if (!Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetIntObj(varPtr[varIndex], intValue * 10);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewIntObj(intValue * 10));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewIntObj(intValue * 10));
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
     } else if (strcmp(subCmd, "div10") == 0) {
 	if (objc != 3) {
 	    goto wrongNumArgs;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	if (Tcl_GetIntFromObj(interp, varPtr[varIndex],
@@ -765,7 +799,7 @@ TestintobjCmd(
 	if (!Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetIntObj(varPtr[varIndex], intValue / 10);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewIntObj(intValue / 10));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewIntObj(intValue / 10));
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
     } else {
@@ -819,11 +853,13 @@ TestlistobjCmd(
     int cmdIndex;		/* Ordinal number of the subcommand */
     int first;			/* First index in the list */
     int count;			/* Count of elements in a list */
+    Tcl_Obj **varPtr;
 
     if (objc < 3) {
 	Tcl_WrongNumArgs(interp, 1, objv, "option arg ?arg...?");
 	return TCL_ERROR;
     }
+    varPtr = GetVarPtr(interp);
     index = Tcl_GetString(objv[2]);
     if (GetVariableIndex(interp, index, &varIndex) != TCL_OK) {
 	return TCL_ERROR;
@@ -837,7 +873,7 @@ TestlistobjCmd(
 	if ((varPtr[varIndex] != NULL) && !Tcl_IsShared(varPtr[varIndex])) {
 	    Tcl_SetListObj(varPtr[varIndex], objc-3, objv+3);
 	} else {
-	    SetVarToObj(varIndex, Tcl_NewListObj(objc-3, objv+3));
+	    SetVarToObj(varPtr, varIndex, Tcl_NewListObj(objc-3, objv+3));
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
 	break;
@@ -847,7 +883,7 @@ TestlistobjCmd(
 	    Tcl_WrongNumArgs(interp, 2, objv, "varIndex");
 	    return TCL_ERROR;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
@@ -864,7 +900,7 @@ TestlistobjCmd(
 	    return TCL_ERROR;
 	}
 	if (Tcl_IsShared(varPtr[varIndex])) {
-	    SetVarToObj(varIndex, Tcl_DuplicateObj(varPtr[varIndex]));
+	    SetVarToObj(varPtr, varIndex, Tcl_DuplicateObj(varPtr[varIndex]));
 	}
 	Tcl_ResetResult(interp);
 	return Tcl_ListObjReplace(interp, varPtr[varIndex], first, count,
@@ -900,6 +936,7 @@ TestobjCmd(
     int varIndex, destIndex, i;
     const char *index, *subCmd, *string;
     const Tcl_ObjType *targetType;
+    Tcl_Obj **varPtr;
 
     if (objc < 2) {
 	wrongNumArgs:
@@ -907,6 +944,7 @@ TestobjCmd(
 	return TCL_ERROR;
     }
 
+    varPtr = GetVarPtr(interp);
     subCmd = Tcl_GetString(objv[1]);
     if (strcmp(subCmd, "assign") == 0) {
 	if (objc != 4) {
@@ -916,14 +954,14 @@ TestobjCmd(
 	if (GetVariableIndex(interp, index, &varIndex) != TCL_OK) {
 	    return TCL_ERROR;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	string = Tcl_GetString(objv[3]);
 	if (GetVariableIndex(interp, string, &destIndex) != TCL_OK) {
 	    return TCL_ERROR;
 	}
-	SetVarToObj(destIndex, varPtr[varIndex]);
+	SetVarToObj(varPtr, destIndex, varPtr[varIndex]);
 	Tcl_SetObjResult(interp, varPtr[destIndex]);
     } else if (strcmp(subCmd, "convert") == 0) {
 	const char *typeName;
@@ -935,7 +973,7 @@ TestobjCmd(
 	if (GetVariableIndex(interp, index, &varIndex) != TCL_OK) {
 	    return TCL_ERROR;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	typeName = Tcl_GetString(objv[3]);
@@ -957,14 +995,14 @@ TestobjCmd(
 	if (GetVariableIndex(interp, index, &varIndex) != TCL_OK) {
 	    return TCL_ERROR;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	string = Tcl_GetString(objv[3]);
 	if (GetVariableIndex(interp, string, &destIndex) != TCL_OK) {
 	    return TCL_ERROR;
 	}
-	SetVarToObj(destIndex, Tcl_DuplicateObj(varPtr[varIndex]));
+	SetVarToObj(varPtr, destIndex, Tcl_DuplicateObj(varPtr[varIndex]));
 	Tcl_SetObjResult(interp, varPtr[destIndex]);
     } else if (strcmp(subCmd, "freeallvars") == 0) {
 	if (objc != 2) {
@@ -984,7 +1022,7 @@ TestobjCmd(
 	if (GetVariableIndex(interp, index, &varIndex) != TCL_OK) {
 	    return TCL_ERROR;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	Tcl_InvalidateStringRep(varPtr[varIndex]);
@@ -997,7 +1035,7 @@ TestobjCmd(
 	if (GetVariableIndex(interp, index, &varIndex) != TCL_OK) {
 	    return TCL_ERROR;
 	}
-	SetVarToObj(varIndex, Tcl_NewObj());
+	SetVarToObj(varPtr, varIndex, Tcl_NewObj());
 	Tcl_SetObjResult(interp, varPtr[varIndex]);
     } else if (strcmp(subCmd, "objtype") == 0) {
 	const char *typeName;
@@ -1024,7 +1062,7 @@ TestobjCmd(
 	if (GetVariableIndex(interp, index, &varIndex) != TCL_OK) {
 	    return TCL_ERROR;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	Tcl_SetObjResult(interp, Tcl_NewIntObj(varPtr[varIndex]->refCount));
@@ -1036,7 +1074,7 @@ TestobjCmd(
 	if (GetVariableIndex(interp, index, &varIndex) != TCL_OK) {
 	    return TCL_ERROR;
 	}
-	if (CheckIfVarUnset(interp, varIndex)) {
+	if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 	    return TCL_ERROR;
 	}
 	if (varPtr[varIndex]->typePtr == NULL) { /* a string! */
@@ -1093,6 +1131,7 @@ TeststringobjCmd(
 #define MAX_STRINGS 11
     const char *index, *string, *strings[MAX_STRINGS+1];
     TestString *strPtr;
+    Tcl_Obj **varPtr;
     static const char *const options[] = {
 	"append", "appendstrings", "get", "get2", "length", "length2",
 	"set", "set2", "setlength", "maxchars", "getunicode",
@@ -1105,6 +1144,7 @@ TeststringobjCmd(
 	return TCL_ERROR;
     }
 
+    varPtr = GetVarPtr(interp);
     index = Tcl_GetString(objv[2]);
     if (GetVariableIndex(interp, index, &varIndex) != TCL_OK) {
 	return TCL_ERROR;
@@ -1123,7 +1163,7 @@ TeststringobjCmd(
 		return TCL_ERROR;
 	    }
 	    if (varPtr[varIndex] == NULL) {
-		SetVarToObj(varIndex, Tcl_NewObj());
+		SetVarToObj(varPtr, varIndex, Tcl_NewObj());
 	    }
 
 	    /*
@@ -1132,7 +1172,7 @@ TeststringobjCmd(
 	     */
 
 	    if (Tcl_IsShared(varPtr[varIndex])) {
-		SetVarToObj(varIndex, Tcl_DuplicateObj(varPtr[varIndex]));
+		SetVarToObj(varPtr, varIndex, Tcl_DuplicateObj(varPtr[varIndex]));
 	    }
 	    string = Tcl_GetString(objv[3]);
 	    Tcl_AppendToObj(varPtr[varIndex], string, length);
@@ -1143,7 +1183,7 @@ TeststringobjCmd(
 		goto wrongNumArgs;
 	    }
 	    if (varPtr[varIndex] == NULL) {
-		SetVarToObj(varIndex, Tcl_NewObj());
+		SetVarToObj(varPtr, varIndex, Tcl_NewObj());
 	    }
 
 	    /*
@@ -1152,7 +1192,7 @@ TeststringobjCmd(
 	     */
 
 	    if (Tcl_IsShared(varPtr[varIndex])) {
-		SetVarToObj(varIndex, Tcl_DuplicateObj(varPtr[varIndex]));
+		SetVarToObj(varPtr, varIndex, Tcl_DuplicateObj(varPtr[varIndex]));
 	    }
 	    for (i = 3;  i < objc;  i++) {
 		strings[i-3] = Tcl_GetString(objv[i]);
@@ -1170,7 +1210,7 @@ TeststringobjCmd(
 	    if (objc != 3) {
 		goto wrongNumArgs;
 	    }
-	    if (CheckIfVarUnset(interp, varIndex)) {
+	    if (CheckIfVarUnset(interp, varPtr,varIndex)) {
 		return TCL_ERROR;
 	    }
 	    Tcl_SetObjResult(interp, varPtr[varIndex]);
@@ -1179,7 +1219,7 @@ TeststringobjCmd(
 	    if (objc != 3) {
 		goto wrongNumArgs;
 	    }
-	    if (CheckIfVarUnset(interp, varIndex)) {
+	    if (CheckIfVarUnset(interp, varPtr, varIndex)) {
 		return TCL_ERROR;
 	    }
 	    string = Tcl_GetString(varPtr[varIndex]);
@@ -1225,7 +1265,7 @@ TeststringobjCmd(
 		    && !Tcl_IsShared(varPtr[varIndex])) {
 		Tcl_SetStringObj(varPtr[varIndex], string, length);
 	    } else {
-		SetVarToObj(varIndex, Tcl_NewStringObj(string, length));
+		SetVarToObj(varPtr, varIndex, Tcl_NewStringObj(string, length));
 	    }
 	    Tcl_SetObjResult(interp, varPtr[varIndex]);
 	    break;
@@ -1233,7 +1273,7 @@ TeststringobjCmd(
 	    if (objc != 4) {
 		goto wrongNumArgs;
 	    }
-	    SetVarToObj(varIndex, objv[3]);
+	    SetVarToObj(varPtr, varIndex, objv[3]);
 	    break;
 	case 8:				/* setlength */
 	    if (objc != 4) {
@@ -1271,7 +1311,7 @@ TeststringobjCmd(
 		goto wrongNumArgs;
 	    }
 	    if (varPtr[varIndex] == NULL) {
-		SetVarToObj(varIndex, Tcl_NewObj());
+		SetVarToObj(varPtr, varIndex, Tcl_NewObj());
 	    }
 
 	    /*
@@ -1280,7 +1320,7 @@ TeststringobjCmd(
 	     */
 
 	    if (Tcl_IsShared(varPtr[varIndex])) {
-		SetVarToObj(varIndex, Tcl_DuplicateObj(varPtr[varIndex]));
+		SetVarToObj(varPtr, varIndex, Tcl_DuplicateObj(varPtr[varIndex]));
 	    }
 
 	    string = Tcl_GetStringFromObj(varPtr[varIndex], &length);
@@ -1302,7 +1342,7 @@ TeststringobjCmd(
 		goto wrongNumArgs;
 	    }
 	    if (varPtr[varIndex] == NULL) {
-		SetVarToObj(varIndex, Tcl_NewObj());
+		SetVarToObj(varPtr, varIndex, Tcl_NewObj());
 	    }
 
 	    /*
@@ -1311,7 +1351,7 @@ TeststringobjCmd(
 	     */
 
 	    if (Tcl_IsShared(varPtr[varIndex])) {
-		SetVarToObj(varIndex, Tcl_DuplicateObj(varPtr[varIndex]));
+		SetVarToObj(varPtr, varIndex, Tcl_DuplicateObj(varPtr[varIndex]));
 	    }
 
 	    unicode = Tcl_GetUnicodeFromObj(varPtr[varIndex], &length);
@@ -1354,6 +1394,7 @@ TeststringobjCmd(
 
 static void
 SetVarToObj(
+    Tcl_Obj **varPtr,
     int varIndex,		/* Designates the assignment variable. */
     Tcl_Obj *objPtr)		/* Points to object to assign to var. */
 {
@@ -1426,6 +1467,7 @@ GetVariableIndex(
 static int
 CheckIfVarUnset(
     Tcl_Interp *interp,		/* Interpreter for error reporting. */
+    Tcl_Obj ** varPtr,
     int varIndex)		/* Index of the test variable to check. */
 {
     if (varPtr[varIndex] == NULL) {