re-base to 'cleaned-up' core-8-6-branch

66 files changed, 359 insertions, 356 deletions

diff --git a/generic/tk3d.c b/generic/tk3d.c
index ce97a2e..87ddf76 100644
--- a/generic/tk3d.c
+++ b/generic/tk3d.c
@@ -236,9 +236,9 @@ Tk_Get3DBorder(
     borderPtr->darkColorPtr = NULL;
     borderPtr->lightColorPtr = NULL;
     borderPtr->shadow = None;
-    borderPtr->bgGC = 0;
-    borderPtr->darkGC = 0;
-    borderPtr->lightGC = 0;
+    borderPtr->bgGC = None;
+    borderPtr->darkGC = None;
+    borderPtr->lightGC = None;
     borderPtr->hashPtr = hashPtr;
     borderPtr->nextPtr = existingBorderPtr;
     Tcl_SetHashValue(hashPtr, borderPtr);
diff --git a/generic/tkBind.c b/generic/tkBind.c
index c8f2610..af5306b 100644
--- a/generic/tkBind.c
+++ b/generic/tkBind.c
@@ -3580,14 +3580,14 @@ DoWarp(
 
     if ((dispPtr->warpWindow == NULL) ||
             (Tk_IsMapped(dispPtr->warpWindow)
-            && Tk_WindowId(dispPtr->warpWindow))) {
+            && (Tk_WindowId(dispPtr->warpWindow) != None))) {
         TkpWarpPointer(dispPtr);
         XForceScreenSaver(dispPtr->display, ScreenSaverReset);
     }
 
     if (dispPtr->warpWindow) {
 	Tcl_Release(dispPtr->warpWindow);
-	dispPtr->warpWindow = 0;
+	dispPtr->warpWindow = None;
     }
     dispPtr->flags &= ~TK_DISPLAY_IN_WARP;
 }
diff --git a/generic/tkBusy.c b/generic/tkBusy.c
index d32800e..514465a 100644
--- a/generic/tkBusy.c
+++ b/generic/tkBusy.c
@@ -205,7 +205,7 @@ DoConfigureNotify(
     if (winPtr->changes.stack_mode == Above) {
 	event.xconfigure.above = winPtr->changes.sibling;
     } else {
-	event.xconfigure.above = 0;
+	event.xconfigure.above = None;
     }
     event.xconfigure.override_redirect = winPtr->atts.override_redirect;
     Tk_HandleEvent(&event);
@@ -421,7 +421,7 @@ MakeTransparentWindowExist(
     int notUsed;
     TkDisplay *dispPtr;
 
-    if (winPtr->window) {
+    if (winPtr->window != None) {
 	return;			/* Window already exists. */
     }
 
@@ -431,7 +431,7 @@ MakeTransparentWindowExist(
 
     TkpMakeTransparentWindowExist(tkwin, parent);
 
-    if (!winPtr->window) {
+    if (winPtr->window == None) {
 	return;			/* Platform didn't make Window. */
     }
 
@@ -458,7 +458,7 @@ MakeTransparentWindowExist(
 
 	for (winPtr2 = winPtr->nextPtr; winPtr2 != NULL;
 		winPtr2 = winPtr2->nextPtr) {
-	    if ((winPtr2->window) &&
+	    if ((winPtr2->window != None) &&
 		    !(winPtr2->flags & (TK_TOP_HIERARCHY|TK_REPARENTED))) {
 		XWindowChanges changes;
 
@@ -568,7 +568,7 @@ CreateBusy(
     busyPtr->height = Tk_Height(tkRef);
     busyPtr->x = Tk_X(tkRef);
     busyPtr->y = Tk_Y(tkRef);
-    busyPtr->cursor = 0;
+    busyPtr->cursor = None;
     Tk_SetClass(tkBusy, "Busy");
     busyPtr->optionTable = Tk_CreateOptionTable(interp, busyOptionSpecs);
     if (Tk_InitOptions(interp, (char *) busyPtr, busyPtr->optionTable,
@@ -598,7 +598,7 @@ CreateBusy(
      */
 
     Tk_ManageGeometry(tkBusy, &busyMgrInfo, busyPtr);
-    if (busyPtr->cursor) {
+    if (busyPtr->cursor != None) {
 	Tk_DefineCursor(tkBusy, busyPtr->cursor);
     }
 
@@ -643,7 +643,7 @@ ConfigureBusy(
 	return TCL_ERROR;
     }
     if (busyPtr->cursor != oldCursor) {
-	if (!busyPtr->cursor) {
+	if (busyPtr->cursor == None) {
 	    Tk_UndefineCursor(busyPtr->tkBusy);
 	} else {
 	    Tk_DefineCursor(busyPtr->tkBusy, busyPtr->cursor);
diff --git a/generic/tkButton.c b/generic/tkButton.c
index 1cf6247..7760359 100644
--- a/generic/tkButton.c
+++ b/generic/tkButton.c
@@ -710,12 +710,12 @@ ButtonCreate(
     butPtr->normalFg = NULL;
     butPtr->activeFg = NULL;
     butPtr->disabledFg = NULL;
-    butPtr->normalTextGC = NULL;
-    butPtr->activeTextGC = NULL;
-    butPtr->disabledGC = NULL;
-    butPtr->stippleGC = NULL;
+    butPtr->normalTextGC = None;
+    butPtr->activeTextGC = None;
+    butPtr->disabledGC = None;
+    butPtr->stippleGC = None;
     butPtr->gray = None;
-    butPtr->copyGC = NULL;
+    butPtr->copyGC = None;
     butPtr->widthPtr = NULL;
     butPtr->width = 0;
     butPtr->heightPtr = NULL;
@@ -740,7 +740,7 @@ ButtonCreate(
     butPtr->onValuePtr = NULL;
     butPtr->offValuePtr = NULL;
     butPtr->tristateValuePtr = NULL;
-    butPtr->cursor = NULL;
+    butPtr->cursor = None;
     butPtr->takeFocusPtr = NULL;
     butPtr->commandPtr = NULL;
     butPtr->flags = 0;
diff --git a/generic/tkCanvArc.c b/generic/tkCanvArc.c
index cd9ab33..4e4c582 100644
--- a/generic/tkCanvArc.c
+++ b/generic/tkCanvArc.c
@@ -290,7 +290,7 @@ CreateArc(
     arcPtr->activeFillStipple = None;
     arcPtr->disabledFillStipple = None;
     arcPtr->style = PIESLICE_STYLE;
-    arcPtr->fillGC = NULL;
+    arcPtr->fillGC = None;
 
     /*
      * Process the arguments to fill in the item record.
@@ -478,7 +478,7 @@ ConfigureArc(
 	mask |= GCCapStyle;
 	newGC = Tk_GetGC(tkwin, mask, &gcValues);
     } else {
-	newGC = NULL;
+	newGC = None;
     }
     if (arcPtr->outline.gc != None) {
 	Tk_FreeGC(Tk_Display(tkwin), arcPtr->outline.gc);
@@ -511,8 +511,10 @@ ConfigureArc(
 	}
       }
 
-    if ((arcPtr->style == ARC_STYLE) || (!color)) {
-	newGC = NULL;
+    if (arcPtr->style == ARC_STYLE) {
+	newGC = None;
+    } else if (color == NULL) {
+	newGC = None;
     } else {
 	gcValues.foreground = color->pixel;
 	if (arcPtr->style == CHORD_STYLE) {
@@ -903,13 +905,13 @@ DisplayArc(
 	} else {
 	    if (arcPtr->style == CHORD_STYLE) {
 		TkFillPolygon(canvas, arcPtr->outlinePtr, CHORD_OUTLINE_PTS,
-			display, drawable, arcPtr->outline.gc, NULL);
+			display, drawable, arcPtr->outline.gc, None);
 	    } else if (arcPtr->style == PIESLICE_STYLE) {
 		TkFillPolygon(canvas, arcPtr->outlinePtr, PIE_OUTLINE1_PTS,
-			display, drawable, arcPtr->outline.gc, NULL);
+			display, drawable, arcPtr->outline.gc, None);
 		TkFillPolygon(canvas, arcPtr->outlinePtr + 2*PIE_OUTLINE1_PTS,
 			PIE_OUTLINE2_PTS, display, drawable,
-			arcPtr->outline.gc, NULL);
+			arcPtr->outline.gc, None);
 	    }
 	}
 
@@ -1901,7 +1903,7 @@ ArcToPostscript(
 	}
 	Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
 
-	if (fillStipple) {
+	if (fillStipple != None) {
 	    Tcl_AppendToObj(psObj, "clip ", -1);
 
 	    Tcl_ResetResult(interp);
@@ -1910,7 +1912,7 @@ ArcToPostscript(
 	    }
 	    Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
 
-	    if (arcPtr->outline.gc) {
+	    if (arcPtr->outline.gc != None) {
 		Tcl_AppendToObj(psObj, "grestore gsave\n", -1);
 	    }
 	} else {
@@ -1953,7 +1955,7 @@ ArcToPostscript(
 		}
 		Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
 
-		if (stipple) {
+		if (stipple != None) {
 		    Tcl_AppendToObj(psObj, "clip ", -1);
 
 		    Tcl_ResetResult(interp);
@@ -1976,7 +1978,7 @@ ArcToPostscript(
 	    }
 	    Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
 
-	    if (stipple) {
+	    if (stipple != None) {
 		Tcl_AppendToObj(psObj, "clip ", -1);
 
 		Tcl_ResetResult(interp);
diff --git a/generic/tkCanvBmap.c b/generic/tkCanvBmap.c
index 42ea262..d7d54f4 100644
--- a/generic/tkCanvBmap.c
+++ b/generic/tkCanvBmap.c
@@ -189,7 +189,7 @@ TkcCreateBitmap(
     bmapPtr->bgColor = NULL;
     bmapPtr->activeBgColor = NULL;
     bmapPtr->disabledBgColor = NULL;
-    bmapPtr->gc = NULL;
+    bmapPtr->gc = None;
 
     /*
      * Process the arguments to fill in the item record. Only 1 (list) or 2 (x
@@ -371,8 +371,8 @@ ConfigureBitmap(
 	}
     }
 
-    if (!bitmap) {
-	newGC = NULL;
+    if (bitmap == None) {
+	newGC = None;
     } else {
 	gcValues.foreground = fgColor->pixel;
 	mask = GCForeground;
diff --git a/generic/tkCanvLine.c b/generic/tkCanvLine.c
index f862238..087aa56 100644
--- a/generic/tkCanvLine.c
+++ b/generic/tkCanvLine.c
@@ -296,7 +296,7 @@ CreateLine(
     linePtr->coordPtr = NULL;
     linePtr->capStyle = CapButt;
     linePtr->joinStyle = JoinRound;
-    linePtr->arrowGC = NULL;
+    linePtr->arrowGC = None;
     linePtr->arrow = ARROWS_NONE;
     linePtr->arrowShapeA = (float)8.0;
     linePtr->arrowShapeB = (float)10.0;
@@ -521,12 +521,12 @@ ConfigureLine(
 #endif
 	arrowGC = Tk_GetGC(tkwin, mask, &gcValues);
     } else {
-	newGC = arrowGC = NULL;
+	newGC = arrowGC = None;
     }
-    if (linePtr->outline.gc) {
+    if (linePtr->outline.gc != None) {
 	Tk_FreeGC(Tk_Display(tkwin), linePtr->outline.gc);
     }
-    if (linePtr->arrowGC) {
+    if (linePtr->arrowGC != None) {
 	Tk_FreeGC(Tk_Display(tkwin), linePtr->arrowGC);
     }
     linePtr->outline.gc = newGC;
@@ -654,7 +654,7 @@ ComputeLineBbox(
 	state = Canvas(canvas)->canvas_state;
     }
 
-    if (!(linePtr->numPoints) || (state==TK_STATE_HIDDEN)) {
+    if (!(linePtr->numPoints) || (state == TK_STATE_HIDDEN)) {
 	linePtr->header.x1 = -1;
 	linePtr->header.x2 = -1;
 	linePtr->header.y1 = -1;
@@ -667,7 +667,7 @@ ComputeLineBbox(
 	if (linePtr->outline.activeWidth > width) {
 	    width = linePtr->outline.activeWidth;
 	}
-    } else if (state==TK_STATE_DISABLED) {
+    } else if (state == TK_STATE_DISABLED) {
 	if (linePtr->outline.disabledWidth > 0) {
 	    width = linePtr->outline.disabledWidth;
 	}
@@ -840,7 +840,7 @@ DisplayLine(
     int numPoints;
     Tk_State state = itemPtr->state;
 
-    if ((!linePtr->numPoints) || !linePtr->outline.gc) {
+    if ((!linePtr->numPoints) || (linePtr->outline.gc == None)) {
 	return;
     }
 
@@ -2277,20 +2277,20 @@ LineToPostscript(
 	if (linePtr->outline.activeWidth > width) {
 	    width = linePtr->outline.activeWidth;
 	}
-	if (linePtr->outline.activeColor) {
+	if (linePtr->outline.activeColor != NULL) {
 	    color = linePtr->outline.activeColor;
 	}
-	if (linePtr->outline.activeStipple) {
+	if (linePtr->outline.activeStipple != None) {
 	    stipple = linePtr->outline.activeStipple;
 	}
     } else if (state == TK_STATE_DISABLED) {
 	if (linePtr->outline.disabledWidth > 0) {
 	    width = linePtr->outline.disabledWidth;
 	}
-	if (linePtr->outline.disabledColor) {
+	if (linePtr->outline.disabledColor != NULL) {
 	    color = linePtr->outline.disabledColor;
 	}
-	if (linePtr->outline.disabledStipple) {
+	if (linePtr->outline.disabledStipple != None) {
 	    stipple = linePtr->outline.disabledStipple;
 	}
     }
@@ -2324,7 +2324,7 @@ LineToPostscript(
 	}
 	Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
 
-	if (stipple) {
+	if (stipple != None) {
 	    Tcl_AppendToObj(psObj, "clip ", -1);
 	    Tcl_ResetResult(interp);
 	    if (Tk_CanvasPsStipple(interp, canvas, stipple) != TCL_OK) {
@@ -2345,7 +2345,7 @@ LineToPostscript(
     Tcl_ResetResult(interp);
     if ((!linePtr->smooth) || (linePtr->numPoints < 3)) {
 	Tk_CanvasPsPath(interp, canvas, linePtr->coordPtr, linePtr->numPoints);
-    } else if (!stipple && linePtr->smooth->postscriptProc) {
+    } else if ((stipple == None) && linePtr->smooth->postscriptProc) {
 	linePtr->smooth->postscriptProc(interp, canvas, linePtr->coordPtr,
 		linePtr->numPoints, linePtr->splineSteps);
     } else {
@@ -2495,7 +2495,7 @@ ArrowheadPostscript(
     Tk_CanvasPsPath(interp, canvas, arrowPtr, PTS_IN_ARROW);
     Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
 
-    if (stipple) {
+    if (stipple != None) {
 	Tcl_AppendToObj(psObj, "clip ", -1);
 
 	Tcl_ResetResult(interp);
diff --git a/generic/tkCanvPoly.c b/generic/tkCanvPoly.c
index d541b3b..b4ef098 100644
--- a/generic/tkCanvPoly.c
+++ b/generic/tkCanvPoly.c
@@ -270,10 +270,10 @@ CreatePolygon(
     polyPtr->fillColor = NULL;
     polyPtr->activeFillColor = NULL;
     polyPtr->disabledFillColor = NULL;
-    polyPtr->fillStipple = 0;
-    polyPtr->activeFillStipple = 0;
-    polyPtr->disabledFillStipple = 0;
-    polyPtr->fillGC = 0;
+    polyPtr->fillStipple = None;
+    polyPtr->activeFillStipple = None;
+    polyPtr->disabledFillStipple = None;
+    polyPtr->fillGC = None;
     polyPtr->smooth = NULL;
     polyPtr->splineSteps = 12;
     polyPtr->autoClosed = 0;
@@ -453,11 +453,11 @@ ConfigurePolygon(
     state = itemPtr->state;
 
     if (polyPtr->outline.activeWidth > polyPtr->outline.width ||
-	    polyPtr->outline.activeDash.number ||
-	    polyPtr->outline.activeColor ||
-	    polyPtr->outline.activeStipple ||
-	    polyPtr->activeFillColor ||
-	    polyPtr->activeFillStipple) {
+	    polyPtr->outline.activeDash.number != 0 ||
+	    polyPtr->outline.activeColor != NULL ||
+	    polyPtr->outline.activeStipple != None ||
+	    polyPtr->activeFillColor != NULL ||
+	    polyPtr->activeFillStipple != None) {
 	itemPtr->redraw_flags |= TK_ITEM_STATE_DEPENDANT;
     } else {
 	itemPtr->redraw_flags &= ~TK_ITEM_STATE_DEPENDANT;
@@ -478,9 +478,9 @@ ConfigurePolygon(
 	mask |= GCCapStyle|GCJoinStyle;
 	newGC = Tk_GetGC(tkwin, mask, &gcValues);
     } else {
-	newGC = 0;
+	newGC = None;
     }
-    if (polyPtr->outline.gc) {
+    if (polyPtr->outline.gc != None) {
 	Tk_FreeGC(Tk_Display(tkwin), polyPtr->outline.gc);
     }
     polyPtr->outline.gc = newGC;
@@ -491,24 +491,24 @@ ConfigurePolygon(
 	if (polyPtr->activeFillColor != NULL) {
 	    color = polyPtr->activeFillColor;
 	}
-	if (polyPtr->activeFillStipple) {
+	if (polyPtr->activeFillStipple != None) {
 	    stipple = polyPtr->activeFillStipple;
 	}
     } else if (state == TK_STATE_DISABLED) {
 	if (polyPtr->disabledFillColor != NULL) {
 	    color = polyPtr->disabledFillColor;
 	}
-	if (polyPtr->disabledFillStipple) {
+	if (polyPtr->disabledFillStipple != None) {
 	    stipple = polyPtr->disabledFillStipple;
 	}
     }
 
     if (color == NULL) {
-	newGC = 0;
+	newGC = None;
     } else {
 	gcValues.foreground = color->pixel;
 	mask = GCForeground;
-	if (stipple) {
+	if (stipple != None) {
 	    gcValues.stipple = stipple;
 	    gcValues.fill_style = FillStippled;
 	    mask |= GCStipple|GCFillStyle;
@@ -518,13 +518,13 @@ ConfigurePolygon(
 	 * Mac OS X CG drawing needs access to the outline linewidth
 	 * even for fills (as linewidth controls antialiasing).
 	 */
-	gcValues.line_width = polyPtr->outline.gc ?
+	gcValues.line_width = polyPtr->outline.gc != None ?
 		polyPtr->outline.gc->line_width : 0;
 	mask |= GCLineWidth;
 #endif
 	newGC = Tk_GetGC(tkwin, mask, &gcValues);
     }
-    if (polyPtr->fillGC) {
+    if (polyPtr->fillGC != None) {
 	Tk_FreeGC(Tk_Display(tkwin), polyPtr->fillGC);
     }
     polyPtr->fillGC = newGC;
@@ -569,28 +569,28 @@ DeletePolygon(
     PolygonItem *polyPtr = (PolygonItem *) itemPtr;
 
     Tk_DeleteOutline(display, &polyPtr->outline);
-    if (polyPtr->coordPtr) {
+    if (polyPtr->coordPtr != NULL) {
 	ckfree(polyPtr->coordPtr);
     }
-    if (polyPtr->fillColor) {
+    if (polyPtr->fillColor != NULL) {
 	Tk_FreeColor(polyPtr->fillColor);
     }
-    if (polyPtr->activeFillColor) {
+    if (polyPtr->activeFillColor != NULL) {
 	Tk_FreeColor(polyPtr->activeFillColor);
     }
-    if (polyPtr->disabledFillColor) {
+    if (polyPtr->disabledFillColor != NULL) {
 	Tk_FreeColor(polyPtr->disabledFillColor);
     }
-    if (polyPtr->fillStipple) {
+    if (polyPtr->fillStipple != None) {
 	Tk_FreeBitmap(display, polyPtr->fillStipple);
     }
-    if (polyPtr->activeFillStipple) {
+    if (polyPtr->activeFillStipple != None) {
 	Tk_FreeBitmap(display, polyPtr->activeFillStipple);
     }
-    if (polyPtr->disabledFillStipple) {
+    if (polyPtr->disabledFillStipple != None) {
 	Tk_FreeBitmap(display, polyPtr->disabledFillStipple);
     }
-    if (polyPtr->fillGC) {
+    if (polyPtr->fillGC != None) {
 	Tk_FreeGC(display, polyPtr->fillGC);
     }
 }
@@ -694,7 +694,7 @@ ComputePolygonBbox(
 	}
     }
 
-    if (polyPtr->outline.gc) {
+    if (polyPtr->outline.gc != None) {
 	tsoffset = &polyPtr->outline.tsoffset;
 	if (tsoffset) {
 	    if (tsoffset->flags & TK_OFFSET_INDEX) {
@@ -836,11 +836,11 @@ TkFillPolygon(
      * allocated.
      */
 
-    if (gc && numPoints > 3) {
+    if (gc != None && numPoints > 3) {
 	XFillPolygon(display, drawable, gc, pointPtr, numPoints, Complex,
 		CoordModeOrigin);
     }
-    if (outlineGC) {
+    if (outlineGC != None) {
 	XDrawLines(display, drawable, outlineGC, pointPtr, numPoints,
 		CoordModeOrigin);
     }
@@ -881,9 +881,9 @@ DisplayPolygon(
     Pixmap stipple = polyPtr->fillStipple;
     double linewidth = polyPtr->outline.width;
 
-    if ((!polyPtr->fillGC && !polyPtr->outline.gc) ||
+    if (((polyPtr->fillGC == None) && (polyPtr->outline.gc == None)) ||
 	    (polyPtr->numPoints < 1) ||
-	    (polyPtr->numPoints < 3 && !polyPtr->outline.gc)) {
+	    (polyPtr->numPoints < 3 && polyPtr->outline.gc == None)) {
 	return;
     }
 
@@ -894,14 +894,14 @@ DisplayPolygon(
 	if (polyPtr->outline.activeWidth > linewidth) {
 	    linewidth = polyPtr->outline.activeWidth;
 	}
-	if (polyPtr->activeFillStipple) {
+	if (polyPtr->activeFillStipple != None) {
 	    stipple = polyPtr->activeFillStipple;
 	}
     } else if (state == TK_STATE_DISABLED) {
 	if (polyPtr->outline.disabledWidth > 0.0) {
 	    linewidth = polyPtr->outline.disabledWidth;
 	}
-	if (polyPtr->disabledFillStipple) {
+	if (polyPtr->disabledFillStipple != None) {
 	    stipple = polyPtr->disabledFillStipple;
 	}
     }
@@ -911,7 +911,7 @@ DisplayPolygon(
      * reset the offset when done, since the GC is supposed to be read-only.
      */
 
-    if (stipple && polyPtr->fillGC) {
+    if ((stipple != None) && (polyPtr->fillGC != None)) {
 	Tk_TSOffset *tsoffset = &polyPtr->tsoffset;
 	int w = 0, h = 0;
 	int flags = tsoffset->flags;
@@ -973,11 +973,11 @@ DisplayPolygon(
 	}
 	numPoints = polyPtr->smooth->coordProc(canvas, polyPtr->coordPtr,
 		polyPtr->numPoints, polyPtr->splineSteps, pointPtr, NULL);
-	if (polyPtr->fillGC) {
+	if (polyPtr->fillGC != None) {
 	    XFillPolygon(display, drawable, polyPtr->fillGC, pointPtr,
 		    numPoints, Complex, CoordModeOrigin);
 	}
-	if (polyPtr->outline.gc) {
+	if (polyPtr->outline.gc != None) {
 	    XDrawLines(display, drawable, polyPtr->outline.gc, pointPtr,
 		    numPoints, CoordModeOrigin);
 	}
@@ -986,7 +986,7 @@ DisplayPolygon(
 	}
     }
     Tk_ResetOutlineGC(canvas, itemPtr, &polyPtr->outline);
-    if (stipple && polyPtr->fillGC) {
+    if ((stipple != None) && (polyPtr->fillGC != None)) {
 	XSetTSOrigin(display, polyPtr->fillGC, 0, 0);
     }
 }
@@ -1299,7 +1299,7 @@ PolygonToPoint(
     if (bestDist <= 0.0) {
 	goto donepoint;
     }
-    if (polyPtr->outline.gc && (polyPtr->joinStyle == JoinRound)) {
+    if ((polyPtr->outline.gc != None) && (polyPtr->joinStyle == JoinRound)) {
 	dist = bestDist - radius;
 	if (dist <= 0.0) {
 	    bestDist = 0.0;
@@ -1309,7 +1309,7 @@ PolygonToPoint(
 	}
     }
 
-    if (!polyPtr->outline.gc || (width <= 1)) {
+    if ((polyPtr->outline.gc == None) || (width <= 1)) {
 	goto donepoint;
     }
 
@@ -1515,7 +1515,7 @@ PolygonToArea(
 	goto donearea;
     }
 
-    if (!polyPtr->outline.gc) {
+    if (polyPtr->outline.gc == None) {
 	goto donearea;
     }
 
@@ -1829,13 +1829,13 @@ PolygonToPostscript(
 	if (polyPtr->outline.activeColor != NULL) {
 	    color = polyPtr->outline.activeColor;
 	}
-	if (polyPtr->outline.activeStipple) {
+	if (polyPtr->outline.activeStipple != None) {
 	    stipple = polyPtr->outline.activeStipple;
 	}
 	if (polyPtr->activeFillColor != NULL) {
 	    fillColor = polyPtr->activeFillColor;
 	}
-	if (polyPtr->activeFillStipple) {
+	if (polyPtr->activeFillStipple != None) {
 	    fillStipple = polyPtr->activeFillStipple;
 	}
     } else if (state == TK_STATE_DISABLED) {
@@ -1845,13 +1845,13 @@ PolygonToPostscript(
 	if (polyPtr->outline.disabledColor != NULL) {
 	    color = polyPtr->outline.disabledColor;
 	}
-	if (polyPtr->outline.disabledStipple) {
+	if (polyPtr->outline.disabledStipple != None) {
 	    stipple = polyPtr->outline.disabledStipple;
 	}
 	if (polyPtr->disabledFillColor != NULL) {
 	    fillColor = polyPtr->disabledFillColor;
 	}
-	if (polyPtr->disabledFillStipple) {
+	if (polyPtr->disabledFillStipple != None) {
 	    fillStipple = polyPtr->disabledFillStipple;
 	}
     }
@@ -1894,7 +1894,7 @@ PolygonToPostscript(
 	}
 	Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
 
-	if (stipple) {
+	if (stipple != None) {
 	    Tcl_AppendToObj(psObj, "clip ", -1);
 
 	    Tcl_ResetResult(interp);
@@ -1926,7 +1926,7 @@ PolygonToPostscript(
 	}
 	Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
 
-	if (fillStipple) {
+	if (fillStipple != None) {
 	    Tcl_AppendToObj(psObj, "eoclip ", -1);
 
 	    Tcl_ResetResult(interp);
@@ -1947,7 +1947,7 @@ PolygonToPostscript(
      * Now draw the outline, if there is one.
      */
 
-    if (color) {
+    if (color != NULL) {
 	Tcl_ResetResult(interp);
 	if (!polyPtr->smooth || !polyPtr->smooth->postscriptProc) {
 	    Tk_CanvasPsPath(interp, canvas, polyPtr->coordPtr,
diff --git a/generic/tkCanvText.c b/generic/tkCanvText.c
index 7f5f23d..eb8dfe3 100644
--- a/generic/tkCanvText.c
+++ b/generic/tkCanvText.c
@@ -256,9 +256,9 @@ CreateText(
     textPtr->disabledColor = NULL;
     textPtr->tkfont	= NULL;
     textPtr->justify	= TK_JUSTIFY_LEFT;
-    textPtr->stipple	= 0;
-    textPtr->activeStipple = 0;
-    textPtr->disabledStipple = 0;
+    textPtr->stipple	= None;
+    textPtr->activeStipple = None;
+    textPtr->disabledStipple = None;
     textPtr->text	= NULL;
     textPtr->width	= 0;
     textPtr->underline	= -1;
@@ -269,9 +269,9 @@ CreateText(
     textPtr->textLayout = NULL;
     textPtr->actualWidth = 0;
     textPtr->drawOrigin[0] = textPtr->drawOrigin[1] = 0.0;
-    textPtr->gc		= 0;
-    textPtr->selTextGC	= 0;
-    textPtr->cursorOffGC = 0;
+    textPtr->gc		= None;
+    textPtr->selTextGC	= None;
+    textPtr->cursorOffGC = None;
     textPtr->sine	= 0.0;
     textPtr->cosine	= 1.0;
 
@@ -419,7 +419,7 @@ ConfigureText(
 
     state = itemPtr->state;
 
-    if (textPtr->activeColor || textPtr->activeStipple) {
+    if (textPtr->activeColor != NULL || textPtr->activeStipple != None) {
 	itemPtr->redraw_flags |= TK_ITEM_STATE_DEPENDANT;
     } else {
 	itemPtr->redraw_flags &= ~TK_ITEM_STATE_DEPENDANT;
@@ -435,26 +435,26 @@ ConfigureText(
 	if (textPtr->activeColor != NULL) {
 	    color = textPtr->activeColor;
 	}
-	if (textPtr->activeStipple) {
+	if (textPtr->activeStipple != None) {
 	    stipple = textPtr->activeStipple;
 	}
     } else if (state == TK_STATE_DISABLED) {
 	if (textPtr->disabledColor != NULL) {
 	    color = textPtr->disabledColor;
 	}
-	if (textPtr->disabledStipple) {
+	if (textPtr->disabledStipple != None) {
 	    stipple = textPtr->disabledStipple;
 	}
     }
 
-    newGC = newSelGC = 0;
-    if (textPtr->tkfont) {
+    newGC = newSelGC = None;
+    if (textPtr->tkfont != NULL) {
 	gcValues.font = Tk_FontId(textPtr->tkfont);
 	mask = GCFont;
-	if (color) {
+	if (color != NULL) {
 	    gcValues.foreground = color->pixel;
 	    mask |= GCForeground;
-	    if (stipple) {
+	    if (stipple != None) {
 		gcValues.stipple = stipple;
 		gcValues.fill_style = FillStippled;
 		mask |= GCStipple|GCFillStyle;
@@ -462,7 +462,7 @@ ConfigureText(
 	    newGC = Tk_GetGC(tkwin, mask, &gcValues);
 	}
 	mask &= ~(GCTile|GCFillStyle|GCStipple);
-	if (stipple) {
+	if (stipple != None) {
 	    gcValues.stipple = stipple;
 	    gcValues.fill_style = FillStippled;
 	    mask |= GCStipple|GCFillStyle;
@@ -472,11 +472,11 @@ ConfigureText(
 	}
 	newSelGC = Tk_GetGC(tkwin, mask|GCForeground, &gcValues);
     }
-    if (textPtr->gc) {
+    if (textPtr->gc != None) {
 	Tk_FreeGC(Tk_Display(tkwin), textPtr->gc);
     }
     textPtr->gc = newGC;
-    if (textPtr->selTextGC) {
+    if (textPtr->selTextGC != None) {
 	Tk_FreeGC(Tk_Display(tkwin), textPtr->selTextGC);
     }
     textPtr->selTextGC = newSelGC;
@@ -491,9 +491,9 @@ ConfigureText(
 	}
 	newGC = Tk_GetGC(tkwin, GCForeground, &gcValues);
     } else {
-	newGC = 0;
+	newGC = None;
     }
-    if (textPtr->cursorOffGC) {
+    if (textPtr->cursorOffGC != None) {
 	Tk_FreeGC(Tk_Display(tkwin), textPtr->cursorOffGC);
     }
     textPtr->cursorOffGC = newGC;
@@ -568,37 +568,37 @@ DeleteText(
 {
     TextItem *textPtr = (TextItem *) itemPtr;
 
-    if (textPtr->color) {
+    if (textPtr->color != NULL) {
 	Tk_FreeColor(textPtr->color);
     }
-    if (textPtr->activeColor) {
+    if (textPtr->activeColor != NULL) {
 	Tk_FreeColor(textPtr->activeColor);
     }
-    if (textPtr->disabledColor) {
+    if (textPtr->disabledColor != NULL) {
 	Tk_FreeColor(textPtr->disabledColor);
     }
     Tk_FreeFont(textPtr->tkfont);
-    if (textPtr->stipple) {
+    if (textPtr->stipple != None) {
 	Tk_FreeBitmap(display, textPtr->stipple);
     }
-    if (textPtr->activeStipple) {
+    if (textPtr->activeStipple != None) {
 	Tk_FreeBitmap(display, textPtr->activeStipple);
     }
-    if (textPtr->disabledStipple) {
+    if (textPtr->disabledStipple != None) {
 	Tk_FreeBitmap(display, textPtr->disabledStipple);
     }
-    if (textPtr->text) {
+    if (textPtr->text != NULL) {
 	ckfree(textPtr->text);
     }
 
     Tk_FreeTextLayout(textPtr->textLayout);
-    if (textPtr->gc) {
+    if (textPtr->gc != None) {
 	Tk_FreeGC(display, textPtr->gc);
     }
-    if (textPtr->selTextGC) {
+    if (textPtr->selTextGC != None) {
 	Tk_FreeGC(display, textPtr->selTextGC);
     }
-    if (textPtr->cursorOffGC) {
+    if (textPtr->cursorOffGC != None) {
 	Tk_FreeGC(display, textPtr->cursorOffGC);
     }
 }
@@ -811,16 +811,16 @@ DisplayCanvText(
     }
     stipple = textPtr->stipple;
     if (Canvas(canvas)->currentItemPtr == itemPtr) {
-	if (textPtr->activeStipple) {
+	if (textPtr->activeStipple != None) {
 	    stipple = textPtr->activeStipple;
 	}
     } else if (state == TK_STATE_DISABLED) {
-	if (textPtr->disabledStipple) {
+	if (textPtr->disabledStipple != None) {
 	    stipple = textPtr->disabledStipple;
 	}
     }
 
-    if (!textPtr->gc) {
+    if (textPtr->gc == None) {
 	return;
     }
 
@@ -830,7 +830,7 @@ DisplayCanvText(
      * read-only.
      */
 
-    if (stipple) {
+    if (stipple != None) {
 	Tk_CanvasSetOffset(canvas, textPtr->gc, &textPtr->tsoffset);
     }
 
@@ -932,7 +932,7 @@ DisplayCanvText(
 		Tk_Fill3DPolygon(Tk_CanvasTkwin(canvas), drawable,
 			textInfoPtr->insertBorder, points, 4,
 			textInfoPtr->insertBorderWidth, TK_RELIEF_RAISED);
-	    } else if (textPtr->cursorOffGC) {
+	    } else if (textPtr->cursorOffGC != None) {
 		/*
 		 * Redraw the background over the area of the cursor, even
 		 * though the cursor is turned off. This guarantees that the
@@ -975,7 +975,7 @@ DisplayCanvText(
 	    textPtr->textLayout, drawableX, drawableY, textPtr->angle,
 	    textPtr->underline);
 
-    if (stipple) {
+    if (stipple != None) {
 	XSetTSOrigin(display, textPtr->gc, 0, 0);
     }
 }
@@ -1559,14 +1559,14 @@ TextToPostscript(
 	if (textPtr->activeColor != NULL) {
 	    color = textPtr->activeColor;
 	}
-	if (textPtr->activeStipple) {
+	if (textPtr->activeStipple != None) {
 	    stipple = textPtr->activeStipple;
 	}
     } else if (state == TK_STATE_DISABLED) {
 	if (textPtr->disabledColor != NULL) {
 	    color = textPtr->disabledColor;
 	}
-	if (textPtr->disabledStipple) {
+	if (textPtr->disabledStipple != None) {
 	    stipple = textPtr->disabledStipple;
 	}
     }
@@ -1598,7 +1598,7 @@ TextToPostscript(
     }
     Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
 
-    if (stipple) {
+    if (stipple != None) {
 	Tcl_ResetResult(interp);
 	Tk_CanvasPsStipple(interp, canvas, stipple);
 	Tcl_AppendPrintfToObj(psObj, "/StippleText {\n    %s} bind def\n",
@@ -1633,7 +1633,7 @@ TextToPostscript(
     Tcl_AppendPrintfToObj(psObj,
 	    "] %d %g %g %s %s DrawText\n",
 	    fm.linespace, x / -2.0, y / 2.0, justify,
-	    (stipple ? "true" : "false"));
+	    ((stipple == None) ? "false" : "true"));
 
     /*
      * Plug the accumulated postscript back into the result.
diff --git a/generic/tkCanvUtil.c b/generic/tkCanvUtil.c
index 5ab3a28..09ce98c 100644
--- a/generic/tkCanvUtil.c
+++ b/generic/tkCanvUtil.c
@@ -961,7 +961,7 @@ void
 Tk_CreateOutline(
     Tk_Outline *outline)	/* Outline structure to be filled in. */
 {
-    outline->gc = NULL;
+    outline->gc = None;
     outline->width = 1.0;
     outline->activeWidth = 0.0;
     outline->disabledWidth = 0.0;
@@ -1477,7 +1477,7 @@ Tk_CanvasPsOutline(
      * Note that psObj might hold an invalid reference now.
      */
 
-    if (stipple) {
+    if (stipple != None) {
 	Tcl_AppendToObj(GetPostscriptBuffer(interp), "StrokeClip ", -1);
 	if (Tk_CanvasPsStipple(interp, canvas, stipple) != TCL_OK) {
 	    return TCL_ERROR;
diff --git a/generic/tkCanvas.c b/generic/tkCanvas.c
index 134ff8d..ecabe22 100644
--- a/generic/tkCanvas.c
+++ b/generic/tkCanvas.c
@@ -678,7 +678,7 @@ Tk_CanvasObjCmd(
     canvasPtr->highlightBgColorPtr = NULL;
     canvasPtr->highlightColorPtr = NULL;
     canvasPtr->inset = 0;
-    canvasPtr->pixmapGC = NULL;
+    canvasPtr->pixmapGC = None;
     canvasPtr->width = None;
     canvasPtr->height = None;
     canvasPtr->confine = 0;
@@ -724,7 +724,7 @@ Tk_CanvasObjCmd(
     canvasPtr->scanYOrigin = 0;
     canvasPtr->hotPtr = NULL;
     canvasPtr->hotPrevPtr = NULL;
-    canvasPtr->cursor = NULL;
+    canvasPtr->cursor = None;
     canvasPtr->takeFocus = NULL;
     canvasPtr->pixelsPerMM = WidthOfScreen(Tk_Screen(newWin));
     canvasPtr->pixelsPerMM /= WidthMMOfScreen(Tk_Screen(newWin));
@@ -2754,7 +2754,7 @@ CanvasEventProc(
 	for (itemPtr = canvasPtr->firstItemPtr; itemPtr != NULL;
 		itemPtr = itemPtr->nextPtr) {
 	    if (AlwaysRedraw(itemPtr)) {
-		ItemDisplay(canvasPtr, itemPtr, 0, 0, 0, 0, 0);
+		ItemDisplay(canvasPtr, itemPtr, None, 0, 0, 0, 0);
 	    }
 	}
     }
diff --git a/generic/tkColor.c b/generic/tkColor.c
index 0798067..9abb448 100644
--- a/generic/tkColor.c
+++ b/generic/tkColor.c
@@ -245,7 +245,7 @@ Tk_GetColor(
      */
 
     tkColPtr->magic = COLOR_MAGIC;
-    tkColPtr->gc = 0;
+    tkColPtr->gc = None;
     tkColPtr->screen = Tk_Screen(tkwin);
     tkColPtr->colormap = Tk_Colormap(tkwin);
     tkColPtr->visual = Tk_Visual(tkwin);
@@ -326,7 +326,7 @@ Tk_GetColorByValue(
 
     tkColPtr = TkpGetColorByValue(tkwin, colorPtr);
     tkColPtr->magic = COLOR_MAGIC;
-    tkColPtr->gc = 0;
+    tkColPtr->gc = None;
     tkColPtr->screen = Tk_Screen(tkwin);
     tkColPtr->colormap = valueKey.colormap;
     tkColPtr->visual = Tk_Visual(tkwin);
@@ -493,7 +493,7 @@ Tk_FreeColor(
 
     if (tkColPtr->gc != None) {
 	XFreeGC(DisplayOfScreen(screen), tkColPtr->gc);
-	tkColPtr->gc = 0;
+	tkColPtr->gc = None;
     }
     TkpFreeColor(tkColPtr);
 
diff --git a/generic/tkConfig.c b/generic/tkConfig.c
index 2465d5b..795a8e8 100644
--- a/generic/tkConfig.c
+++ b/generic/tkConfig.c
@@ -800,7 +800,7 @@ DoObjConfig(
 	Tk_Cursor newCursor;
 
 	if (nullOK && ObjectIsEmpty(valuePtr)) {
-	    newCursor = 0;
+	    newCursor = None;
 	    valuePtr = NULL;
 	} else {
 	    newCursor = Tk_AllocCursorFromObj(interp, tkwin, valuePtr);
@@ -862,7 +862,7 @@ DoObjConfig(
 
 	if (nullOK && ObjectIsEmpty(valuePtr)) {
 	    valuePtr = NULL;
-	    newWin = 0;
+	    newWin = None;
 	} else {
 	    if (TkGetWindowFromObj(interp, tkwin, valuePtr,
 		    &newWin) != TCL_OK) {
@@ -1668,7 +1668,7 @@ FreeResources(
 	if (internalFormExists) {
 	    if (*((Tk_Cursor *) internalPtr) != None) {
 		Tk_FreeCursor(Tk_Display(tkwin), *((Tk_Cursor *) internalPtr));
-		*((Tk_Cursor *) internalPtr) = 0;
+		*((Tk_Cursor *) internalPtr) = None;
 	    }
 	} else if (objPtr != NULL) {
 	    Tk_FreeCursorFromObj(tkwin, objPtr);
diff --git a/generic/tkCursor.c b/generic/tkCursor.c
index 18a0d72..6b2d5f4 100644
--- a/generic/tkCursor.c
+++ b/generic/tkCursor.c
@@ -150,7 +150,7 @@ Tk_AllocCursorFromObj(
     cursorPtr = TkcGetCursor(interp, tkwin, Tcl_GetString(objPtr));
     objPtr->internalRep.twoPtrValue.ptr1 = cursorPtr;
     if (cursorPtr == NULL) {
-	return 0;
+	return None;
     }
     cursorPtr->objRefCount++;
     return cursorPtr->cursor;
@@ -188,7 +188,11 @@ Tk_GetCursor(
 				 * details on legal syntax. */
 {
     TkCursor *cursorPtr = TkcGetCursor(interp, tkwin, string);
-    return cursorPtr ? cursorPtr->cursor : NULL;
+
+    if (cursorPtr == NULL) {
+	return None;
+    }
+    return cursorPtr->cursor;
 }
 
 /*
@@ -384,7 +388,7 @@ Tk_GetCursorFromData(
 
   error:
     Tcl_DeleteHashEntry(dataHashPtr);
-    return 0;
+    return None;
 }
 
 /*
diff --git a/generic/tkEntry.c b/generic/tkEntry.c
index 9df8da6..678691f 100644
--- a/generic/tkEntry.c
+++ b/generic/tkEntry.c
@@ -524,16 +524,16 @@ Tk_EntryObjCmd(
     entryPtr->selectFirst	= -1;
     entryPtr->selectLast	= -1;
 
-    entryPtr->cursor		= NULL;
+    entryPtr->cursor		= None;
     entryPtr->exportSelection	= 1;
     entryPtr->justify		= TK_JUSTIFY_LEFT;
     entryPtr->relief		= TK_RELIEF_FLAT;
     entryPtr->state		= STATE_NORMAL;
     entryPtr->displayString	= entryPtr->string;
     entryPtr->inset		= XPAD;
-    entryPtr->textGC		= NULL;
-    entryPtr->selTextGC		= NULL;
-    entryPtr->highlightGC	= NULL;
+    entryPtr->textGC		= None;
+    entryPtr->selTextGC		= None;
+    entryPtr->highlightGC	= None;
     entryPtr->avgWidth		= 1;
     entryPtr->validate		= VALIDATE_NONE;
 
@@ -1430,7 +1430,7 @@ EntryWorldChanged(
     ClientData instanceData)	/* Information about widget. */
 {
     XGCValues gcValues;
-    GC gc = NULL;
+    GC gc = None;
     unsigned long mask;
     Tk_3DBorder border;
     XColor *colorPtr;
@@ -2457,9 +2457,9 @@ EntryEventProc(
 	    } else if ((elem == SEL_BUTTONDOWN) || (elem == SEL_BUTTONUP)) {
 		cursor = sbPtr->bCursor;
 	    } else {
-		cursor = NULL;
+		cursor = None;
 	    }
-	    if (cursor) {
+	    if (cursor != None) {
 		Tk_DefineCursor(entryPtr->tkwin, cursor);
 	    } else {
 		Tk_UndefineCursor(entryPtr->tkwin);
@@ -3633,22 +3633,22 @@ Tk_SpinboxObjCmd(
     entryPtr->selectFirst	= -1;
     entryPtr->selectLast	= -1;
 
-    entryPtr->cursor		= NULL;
+    entryPtr->cursor		= None;
     entryPtr->exportSelection	= 1;
     entryPtr->justify		= TK_JUSTIFY_LEFT;
     entryPtr->relief		= TK_RELIEF_FLAT;
     entryPtr->state		= STATE_NORMAL;
     entryPtr->displayString	= entryPtr->string;
     entryPtr->inset		= XPAD;
-    entryPtr->textGC		= NULL;
-    entryPtr->selTextGC		= NULL;
-    entryPtr->highlightGC	= NULL;
+    entryPtr->textGC		= None;
+    entryPtr->selTextGC		= None;
+    entryPtr->highlightGC	= None;
     entryPtr->avgWidth		= 1;
     entryPtr->validate		= VALIDATE_NONE;
 
     sbPtr->selElement		= SEL_NONE;
     sbPtr->curElement		= SEL_NONE;
-    sbPtr->bCursor		= NULL;
+    sbPtr->bCursor		= None;
     sbPtr->repeatDelay		= 400;
     sbPtr->repeatInterval	= 100;
     sbPtr->fromValue		= 0.0;
diff --git a/generic/tkEntry.h b/generic/tkEntry.h
index 15b4c21..12c0374 100644
--- a/generic/tkEntry.h
+++ b/generic/tkEntry.h
@@ -221,7 +221,7 @@ typedef struct {
 				 * value that the users requests. Malloc'ed */
     char *valueFormat;		/* Sprintf conversion specifier used for the
 				 * value. */
-    char digitFormat[14];	/* Sprintf conversion specifier computed from
+    char digitFormat[16];	/* Sprintf conversion specifier computed from
 				 * digits and other information; used for the
 				 * value. */
 
diff --git a/generic/tkEvent.c b/generic/tkEvent.c
index b68ba54..d058e7c 100644
--- a/generic/tkEvent.c
+++ b/generic/tkEvent.c
@@ -1439,7 +1439,7 @@ TkEventDeadWindow(
 		ipPtr->nextHandler = NULL;
 	    }
 	    if (ipPtr->winPtr == winPtr) {
-		ipPtr->winPtr = 0;
+		ipPtr->winPtr = None;
 	    }
 	}
 	ckfree(handlerPtr);
diff --git a/generic/tkFrame.c b/generic/tkFrame.c
index 81b6405..0f1a1b3 100644
--- a/generic/tkFrame.c
+++ b/generic/tkFrame.c
@@ -662,13 +662,13 @@ CreateFrame(
     framePtr->type = type;
     framePtr->colormap = colormap;
     framePtr->relief = TK_RELIEF_FLAT;
-    framePtr->cursor = NULL;
+    framePtr->cursor = None;
 
     if (framePtr->type == TYPE_LABELFRAME) {
 	Labelframe *labelframePtr = (Labelframe *) framePtr;
 
 	labelframePtr->labelAnchor = LABELANCHOR_NW;
-	labelframePtr->textGC = NULL;
+	labelframePtr->textGC = None;
     }
 
     /*
diff --git a/generic/tkImgBmap.c b/generic/tkImgBmap.c
index aa977c4..0906673 100644
--- a/generic/tkImgBmap.c
+++ b/generic/tkImgBmap.c
@@ -403,18 +403,18 @@ ImgBmapConfigureInstance(
 		(unsigned) masterPtr->height);
     }
 
-    if (oldMask) {
+    if (oldMask != None) {
 	Tk_FreePixmap(Tk_Display(instancePtr->tkwin), oldMask);
     }
-    if (oldBitmap) {
+    if (oldBitmap != None) {
 	Tk_FreePixmap(Tk_Display(instancePtr->tkwin), oldBitmap);
     }
 
-    if (masterPtr->data) {
+    if (masterPtr->data != NULL) {
 	gcValues.foreground = instancePtr->fg->pixel;
 	gcValues.graphics_exposures = False;
 	mask = GCForeground|GCGraphicsExposures;
-	if (instancePtr->bg) {
+	if (instancePtr->bg != NULL) {
 	    gcValues.background = instancePtr->bg->pixel;
 	    mask |= GCBackground;
 	    if (instancePtr->mask != None) {
@@ -427,9 +427,9 @@ ImgBmapConfigureInstance(
 	}
 	gc = Tk_GetGC(instancePtr->tkwin, mask, &gcValues);
     } else {
-	gc = NULL;
+	gc = None;
     }
-    if (instancePtr->gc) {
+    if (instancePtr->gc != None) {
 	Tk_FreeGC(Tk_Display(instancePtr->tkwin), instancePtr->gc);
     }
     instancePtr->gc = gc;
@@ -441,10 +441,10 @@ ImgBmapConfigureInstance(
      * it clear that this instance cannot be displayed. Then report the error.
      */
 
-    if (instancePtr->gc) {
+    if (instancePtr->gc != None) {
 	Tk_FreeGC(Tk_Display(instancePtr->tkwin), instancePtr->gc);
     }
-    instancePtr->gc = NULL;
+    instancePtr->gc = None;
     Tcl_AppendObjToErrorInfo(masterPtr->interp, Tcl_ObjPrintf(
 	    "\n    (while configuring image \"%s\")", Tk_NameOfImage(
 	    masterPtr->tkMaster)));
@@ -848,7 +848,7 @@ ImgBmapGet(
     instancePtr->bg = NULL;
     instancePtr->bitmap = None;
     instancePtr->mask = None;
-    instancePtr->gc = NULL;
+    instancePtr->gc = None;
     instancePtr->nextPtr = masterPtr->instancePtr;
     masterPtr->instancePtr = instancePtr;
     ImgBmapConfigureInstance(instancePtr);
diff --git a/generic/tkImgPhInstance.c b/generic/tkImgPhInstance.c
index 27d2766..3314f5e 100644
--- a/generic/tkImgPhInstance.c
+++ b/generic/tkImgPhInstance.c
@@ -167,7 +167,7 @@ TkImgPhotoConfigureInstance(
      * has the side effect of allocating a pixmap for us.
      */
 
-    if (!instancePtr->pixels || (instancePtr->error == NULL)
+    if ((instancePtr->pixels == None) || (instancePtr->error == NULL)
 	    || (instancePtr->width != masterPtr->width)
 	    || (instancePtr->height != masterPtr->height)) {
 	TkImgPhotoInstanceSetSize(instancePtr);
@@ -285,7 +285,7 @@ TkImgPhotoGet(
     Tk_PreserveColormap(instancePtr->display, instancePtr->colormap);
     instancePtr->refCount = 1;
     instancePtr->colorTablePtr = NULL;
-    instancePtr->pixels = 0;
+    instancePtr->pixels = None;
     instancePtr->error = NULL;
     instancePtr->width = 0;
     instancePtr->height = 0;
@@ -621,7 +621,7 @@ TkImgPhotoDisplay(
      * the image instance so it can't be displayed.
      */
 
-    if (!instancePtr->pixels) {
+    if (instancePtr->pixels == None) {
 	return;
     }
 
@@ -697,7 +697,7 @@ TkImgPhotoDisplay(
 	XCopyArea(display, instancePtr->pixels, drawable, instancePtr->gc,
 		imageX, imageY, (unsigned) width, (unsigned) height,
 		drawableX, drawableY);
-	XSetClipMask(display, instancePtr->gc, 0);
+	XSetClipMask(display, instancePtr->gc, None);
 	XSetClipOrigin(display, instancePtr->gc, 0, 0);
     }
     XFlush(display);
@@ -784,7 +784,7 @@ TkImgPhotoInstanceSetSize(
 
     if ((instancePtr->width != masterPtr->width)
 	    || (instancePtr->height != masterPtr->height)
-	    || !instancePtr->pixels) {
+	    || (instancePtr->pixels == None)) {
 	newPixmap = Tk_GetPixmap(instancePtr->display,
 		RootWindow(instancePtr->display,
 			instancePtr->visualInfo.screen),
@@ -806,7 +806,7 @@ TkImgPhotoInstanceSetSize(
 
 	TkSetPixmapColormap(newPixmap, instancePtr->colormap);
 
-	if (instancePtr->pixels) {
+	if (instancePtr->pixels != None) {
 	    /*
 	     * Copy any common pixels from the old pixmap and free it.
 	     */
@@ -1587,10 +1587,10 @@ TkImgDisposeInstance(
     PhotoInstance *instancePtr = clientData;
     PhotoInstance *prevPtr;
 
-    if (instancePtr->pixels) {
+    if (instancePtr->pixels != None) {
 	Tk_FreePixmap(instancePtr->display, instancePtr->pixels);
     }
-    if (instancePtr->gc) {
+    if (instancePtr->gc != None) {
 	Tk_FreeGC(instancePtr->display, instancePtr->gc);
     }
     if (instancePtr->imagePtr != NULL) {
diff --git a/generic/tkListbox.c b/generic/tkListbox.c
index b2584da..5f650fe 100644
--- a/generic/tkListbox.c
+++ b/generic/tkListbox.c
@@ -542,13 +542,13 @@ Tk_ListboxObjCmd(
     listPtr->itemAttrTable	 = ckalloc(sizeof(Tcl_HashTable));
     Tcl_InitHashTable(listPtr->itemAttrTable, TCL_ONE_WORD_KEYS);
     listPtr->relief		 = TK_RELIEF_RAISED;
-    listPtr->textGC		 = NULL;
-    listPtr->selFgColorPtr	 = NULL;
-    listPtr->selTextGC		 = NULL;
+    listPtr->textGC		 = None;
+    listPtr->selFgColorPtr	 = None;
+    listPtr->selTextGC		 = None;
     listPtr->fullLines		 = 1;
     listPtr->xScrollUnit	 = 1;
     listPtr->exportSelection	 = 1;
-    listPtr->cursor		 = NULL;
+    listPtr->cursor		 = None;
     listPtr->state		 = STATE_NORMAL;
     listPtr->gray		 = None;
     listPtr->justify             = TK_JUSTIFY_LEFT;
diff --git a/generic/tkMenu.c b/generic/tkMenu.c
index a31666d..26ffc88 100644
--- a/generic/tkMenu.c
+++ b/generic/tkMenu.c
@@ -455,7 +455,7 @@ Tk_MenuObjCmd(
 	    Tk_PathName(menuPtr->tkwin), MenuWidgetObjCmd, menuPtr,
 	    MenuCmdDeletedProc);
     menuPtr->active = -1;
-    menuPtr->cursorPtr = NULL;
+    menuPtr->cursorPtr = None;
     menuPtr->masterMenuPtr = menuPtr;
     menuPtr->menuType = UNKNOWN_TYPE;
     TkMenuInitializeDrawingFields(menuPtr);
diff --git a/generic/tkMenuDraw.c b/generic/tkMenuDraw.c
index e9b1c98..3f492db 100644
--- a/generic/tkMenuDraw.c
+++ b/generic/tkMenuDraw.c
@@ -43,12 +43,12 @@ void
 TkMenuInitializeDrawingFields(
     TkMenu *menuPtr)		/* The menu we are initializing. */
 {
-    menuPtr->textGC = NULL;
+    menuPtr->textGC = None;
     menuPtr->gray = None;
-    menuPtr->disabledGC = NULL;
-    menuPtr->activeGC = NULL;
-    menuPtr->indicatorGC = NULL;
-    menuPtr->disabledImageGC = NULL;
+    menuPtr->disabledGC = None;
+    menuPtr->activeGC = None;
+    menuPtr->indicatorGC = None;
+    menuPtr->disabledImageGC = None;
     menuPtr->totalWidth = menuPtr->totalHeight = 0;
 }
 
@@ -79,10 +79,10 @@ TkMenuInitializeEntryDrawingFields(
     mePtr->y = 0;
     mePtr->indicatorSpace = 0;
     mePtr->labelWidth = 0;
-    mePtr->textGC = NULL;
-    mePtr->activeGC = NULL;
-    mePtr->disabledGC = NULL;
-    mePtr->indicatorGC = NULL;
+    mePtr->textGC = None;
+    mePtr->activeGC = None;
+    mePtr->disabledGC = None;
+    mePtr->indicatorGC = None;
 }
 
 /*
@@ -385,10 +385,10 @@ TkMenuConfigureEntryDrawOptions(
 		GCForeground|GCBackground|GCFont|GCGraphicsExposures,
 		&gcValues);
     } else {
-	newGC = NULL;
-	newActiveGC = NULL;
-	newDisabledGC = NULL;
-	newIndicatorGC = NULL;
+	newGC = None;
+	newActiveGC = None;
+	newDisabledGC = None;
+	newIndicatorGC = None;
     }
     if (mePtr->textGC != None) {
 	Tk_FreeGC(menuPtr->display, mePtr->textGC);
diff --git a/generic/tkMenubutton.c b/generic/tkMenubutton.c
index f0927c9..2c1676c 100644
--- a/generic/tkMenubutton.c
+++ b/generic/tkMenubutton.c
@@ -279,11 +279,11 @@ Tk_MenubuttonObjCmd(
     mbPtr->normalFg = NULL;
     mbPtr->activeFg = NULL;
     mbPtr->disabledFg = NULL;
-    mbPtr->normalTextGC = NULL;
-    mbPtr->activeTextGC = NULL;
+    mbPtr->normalTextGC = None;
+    mbPtr->activeTextGC = None;
     mbPtr->gray = None;
-    mbPtr->disabledGC = NULL;
-    mbPtr->stippleGC = NULL;
+    mbPtr->disabledGC = None;
+    mbPtr->stippleGC = None;
     mbPtr->leftBearing = 0;
     mbPtr->rightBearing = 0;
     mbPtr->widthString = NULL;
@@ -300,7 +300,7 @@ Tk_MenubuttonObjCmd(
     mbPtr->indicatorWidth = 0;
     mbPtr->indicatorHeight = 0;
     mbPtr->direction = DIRECTION_FLUSH;
-    mbPtr->cursor = NULL;
+    mbPtr->cursor = None;
     mbPtr->takeFocus = NULL;
     mbPtr->flags = 0;
 
diff --git a/generic/tkMessage.c b/generic/tkMessage.c
index e44da06..f65b046 100644
--- a/generic/tkMessage.c
+++ b/generic/tkMessage.c
@@ -256,11 +256,11 @@ Tk_MessageObjCmd(
 	    MessageCmdDeletedProc);
     msgPtr->optionTable = optionTable;
     msgPtr->relief = TK_RELIEF_FLAT;
-    msgPtr->textGC = NULL;
+    msgPtr->textGC = None;
     msgPtr->anchor = TK_ANCHOR_CENTER;
     msgPtr->aspect = 150;
     msgPtr->justify = TK_JUSTIFY_LEFT;
-    msgPtr->cursor = NULL;
+    msgPtr->cursor = None;
 
     Tk_SetClass(msgPtr->tkwin, "Message");
     Tk_SetClassProcs(msgPtr->tkwin, &messageClass, msgPtr);
@@ -525,7 +525,7 @@ MessageWorldChanged(
     ClientData instanceData)	/* Information about widget. */
 {
     XGCValues gcValues;
-    GC gc = NULL;
+    GC gc = None;
     Tk_FontMetrics fm;
     Message *msgPtr = instanceData;
 
diff --git a/generic/tkOldConfig.c b/generic/tkOldConfig.c
index 698e8a9..920d93e 100644
--- a/generic/tkOldConfig.c
+++ b/generic/tkOldConfig.c
@@ -477,7 +477,7 @@ DoConfig(
 	    Tk_Cursor newCursor, oldCursor;
 
 	    if (nullValue) {
-		newCursor = 0;
+		newCursor = None;
 	    } else {
 		uid = valueIsUid ? (Tk_Uid) value : Tk_GetUid(value);
 		newCursor = Tk_GetCursor(interp, tkwin, uid);
@@ -1024,7 +1024,7 @@ Tk_FreeOptions(
 	case TK_CONFIG_ACTIVE_CURSOR:
 	    if (*((Tk_Cursor *) ptr) != None) {
 		Tk_FreeCursor(display, *((Tk_Cursor *) ptr));
-		*((Tk_Cursor *) ptr) = NULL;
+		*((Tk_Cursor *) ptr) = None;
 	    }
 	}
     }
diff --git a/generic/tkPanedWindow.c b/generic/tkPanedWindow.c
index 8233d35..45d784a 100644
--- a/generic/tkPanedWindow.c
+++ b/generic/tkPanedWindow.c
@@ -448,9 +448,9 @@ Tk_PanedWindowObjCmd(
     pwPtr->optionTable = pwOpts->pwOptions;
     pwPtr->slaveOpts = pwOpts->slaveOpts;
     pwPtr->relief = TK_RELIEF_RAISED;
-    pwPtr->gc = NULL;
-    pwPtr->cursor = NULL;
-    pwPtr->sashCursor = NULL;
+    pwPtr->gc = None;
+    pwPtr->cursor = None;
+    pwPtr->sashCursor = None;
 
     /*
      * Keep a hold of the associated tkwin until we destroy the widget,
@@ -2044,10 +2044,10 @@ Unlink(
 
     for (i = 0; i < masterPtr->numSlaves; i++) {
 	if (masterPtr->slaves[i]->before == slavePtr->tkwin) {
-	    masterPtr->slaves[i]->before = NULL;
+	    masterPtr->slaves[i]->before = None;
 	}
 	if (masterPtr->slaves[i]->after == slavePtr->tkwin) {
-	    masterPtr->slaves[i]->after = NULL;
+	    masterPtr->slaves[i]->after = None;
 	}
     }
 
diff --git a/generic/tkPlace.c b/generic/tkPlace.c
index c1b16b3..9fa406a 100644
--- a/generic/tkPlace.c
+++ b/generic/tkPlace.c
@@ -395,7 +395,7 @@ CreateSlave(
     slavePtr = ckalloc(sizeof(Slave));
     memset(slavePtr, 0, sizeof(Slave));
     slavePtr->tkwin = tkwin;
-    slavePtr->inTkwin = 0;
+    slavePtr->inTkwin = None;
     slavePtr->anchor = TK_ANCHOR_NW;
     slavePtr->borderMode = BM_INSIDE;
     slavePtr->optionTable = table;
diff --git a/generic/tkRectOval.c b/generic/tkRectOval.c
index 30e1d50..4d48fe7 100644
--- a/generic/tkRectOval.c
+++ b/generic/tkRectOval.c
@@ -258,7 +258,7 @@ CreateRectOval(
     rectOvalPtr->fillStipple = None;
     rectOvalPtr->activeFillStipple = None;
     rectOvalPtr->disabledFillStipple = None;
-    rectOvalPtr->fillGC = NULL;
+    rectOvalPtr->fillGC = None;
 
     /*
      * Process the arguments to fill in the item record.
@@ -466,9 +466,9 @@ ConfigureRectOval(
 	mask |= GCCapStyle;
 	newGC = Tk_GetGC(tkwin, mask, &gcValues);
     } else {
-	newGC = NULL;
+	newGC = None;
     }
-    if (rectOvalPtr->outline.gc) {
+    if (rectOvalPtr->outline.gc != None) {
 	Tk_FreeGC(Tk_Display(tkwin), rectOvalPtr->outline.gc);
     }
     rectOvalPtr->outline.gc = newGC;
@@ -499,8 +499,8 @@ ConfigureRectOval(
 	}
     }
 
-    if (!color) {
-	newGC = NULL;
+    if (color == NULL) {
+	newGC = None;
     } else {
 	gcValues.foreground = color->pixel;
 	if (stipple != None) {
@@ -516,13 +516,13 @@ ConfigureRectOval(
 	 * fills (as linewidth controls antialiasing).
 	 */
 
-	gcValues.line_width = rectOvalPtr->outline.gc ?
+	gcValues.line_width = rectOvalPtr->outline.gc != None ?
 		rectOvalPtr->outline.gc->line_width : 0;
 	mask |= GCLineWidth;
 #endif
 	newGC = Tk_GetGC(tkwin, mask, &gcValues);
     }
-    if (rectOvalPtr->fillGC) {
+    if (rectOvalPtr->fillGC != None) {
 	Tk_FreeGC(Tk_Display(tkwin), rectOvalPtr->fillGC);
     }
     rectOvalPtr->fillGC = newGC;
@@ -1470,7 +1470,7 @@ RectOvalToPostscript(
 	}
 	Tcl_AppendObjToObj(psObj, Tcl_GetObjResult(interp));
 
-	if (fillStipple) {
+	if (fillStipple != None) {
 	    Tcl_AppendToObj(psObj, "clip ", -1);
 
 	    Tcl_ResetResult(interp);
diff --git a/generic/tkScale.c b/generic/tkScale.c
index 71de55f..af45afa 100644
--- a/generic/tkScale.c
+++ b/generic/tkScale.c
@@ -270,11 +270,11 @@ Tk_ScaleObjCmd(
     scalePtr->activeBorder	= NULL;
     scalePtr->sliderRelief	= TK_RELIEF_RAISED;
     scalePtr->troughColorPtr	= NULL;
-    scalePtr->troughGC		= NULL;
-    scalePtr->copyGC		= NULL;
+    scalePtr->troughGC		= None;
+    scalePtr->copyGC		= None;
     scalePtr->tkfont		= NULL;
     scalePtr->textColorPtr	= NULL;
-    scalePtr->textGC		= NULL;
+    scalePtr->textGC		= None;
     scalePtr->relief		= TK_RELIEF_FLAT;
     scalePtr->highlightWidth	= 0;
     scalePtr->highlightBorder	= NULL;
@@ -291,7 +291,7 @@ Tk_ScaleObjCmd(
     scalePtr->vertTroughX	= 0;
     scalePtr->vertLabelX	= 0;
     scalePtr->fontHeight	= 0;
-    scalePtr->cursor		= NULL;
+    scalePtr->cursor		= None;
     scalePtr->takeFocusPtr	= NULL;
     scalePtr->flags		= NEVER_SET;
 
diff --git a/generic/tkScale.h b/generic/tkScale.h
index 73678ed..aa0feff 100644
--- a/generic/tkScale.h
+++ b/generic/tkScale.h
@@ -73,7 +73,7 @@ typedef struct TkScale {
 				 * values. 0 means we get to choose the number
 				 * based on resolution and/or the range of the
 				 * scale. */
-    char format[14];		/* Sprintf conversion specifier computed from
+    char format[16];		/* Sprintf conversion specifier computed from
 				 * digits and other information. */
     double bigIncrement;	/* Amount to use for large increments to scale
 				 * value. (0 means we pick a value). */
diff --git a/generic/tkScrollbar.c b/generic/tkScrollbar.c
index 9a85532..5017d30 100644
--- a/generic/tkScrollbar.c
+++ b/generic/tkScrollbar.c
@@ -185,7 +185,7 @@ Tk_ScrollbarObjCmd(
     scrollPtr->lastUnit = 0;
     scrollPtr->firstFraction = 0.0;
     scrollPtr->lastFraction = 0.0;
-    scrollPtr->cursor = NULL;
+    scrollPtr->cursor = None;
     scrollPtr->takeFocus = NULL;
     scrollPtr->flags = 0;
 
diff --git a/generic/tkSquare.c b/generic/tkSquare.c
index 39083d4..36d2d6e 100644
--- a/generic/tkSquare.c
+++ b/generic/tkSquare.c
@@ -169,7 +169,7 @@ SquareObjCmd(
     squarePtr->widgetCmd = Tcl_CreateObjCommand(interp,
 	    Tk_PathName(squarePtr->tkwin), SquareWidgetObjCmd, squarePtr,
 	    SquareDeletedProc);
-    squarePtr->gc = NULL;
+    squarePtr->gc = None;
     squarePtr->optionTable = optionTable;
 
     if (Tk_InitOptions(interp, (char *) squarePtr, optionTable, tkwin)
diff --git a/generic/tkText.c b/generic/tkText.c
index 6c1512d..3d9977f 100644
--- a/generic/tkText.c
+++ b/generic/tkText.c
@@ -586,7 +586,7 @@ CreateWidget(
 
     textPtr->state = TK_TEXT_STATE_NORMAL;
     textPtr->relief = TK_RELIEF_FLAT;
-    textPtr->cursor = NULL;
+    textPtr->cursor = None;
     textPtr->charWidth = 1;
     textPtr->charHeight = 10;
     textPtr->wrapMode = TEXT_WRAPMODE_CHAR;
@@ -2294,10 +2294,10 @@ ConfigureText(
     if ((textPtr->selTagPtr->border != NULL)
 	    || (textPtr->selTagPtr->selBorder != NULL)
 	    || (textPtr->selTagPtr->reliefString != NULL)
-	    || textPtr->selTagPtr->bgStipple
+	    || (textPtr->selTagPtr->bgStipple != None)
 	    || (textPtr->selTagPtr->fgColor != NULL)
 	    || (textPtr->selTagPtr->selFgColor != NULL)
-	    || textPtr->selTagPtr->fgStipple
+	    || (textPtr->selTagPtr->fgStipple != None)
 	    || (textPtr->selTagPtr->overstrikeString != NULL)
 	    || (textPtr->selTagPtr->overstrikeColor != NULL)
 	    || (textPtr->selTagPtr->underlineString != NULL)
diff --git a/generic/tkTextDisp.c b/generic/tkTextDisp.c
index 4fb30e0..356e8b7 100644
--- a/generic/tkTextDisp.c
+++ b/generic/tkTextDisp.c
@@ -666,7 +666,7 @@ TkTextCreateDInfo(
     dInfoPtr = ckalloc(sizeof(TextDInfo));
     Tcl_InitHashTable(&dInfoPtr->styleTable, sizeof(StyleValues)/sizeof(int));
     dInfoPtr->dLinePtr = NULL;
-    dInfoPtr->copyGC = NULL;
+    dInfoPtr->copyGC = None;
     gcValues.graphics_exposures = True;
     dInfoPtr->scrollGC = Tk_GetGC(textPtr->tkwin, GCGraphicsExposures,
 	    &gcValues);
@@ -862,7 +862,7 @@ GetStyle(
             border = tagPtr->selBorder;
         }
 
-        if ((tagPtr->selFgColor) && (isSelected)) {
+        if ((tagPtr->selFgColor != None) && (isSelected)) {
             fgColor = tagPtr->selFgColor;
         }
 
@@ -889,7 +889,7 @@ GetStyle(
 	    styleValues.bgStipple = tagPtr->bgStipple;
 	    bgStipplePrio = tagPtr->priority;
 	}
-	if (fgColor && (tagPtr->priority > fgPrio)) {
+	if ((fgColor != None) && (tagPtr->priority > fgPrio)) {
 	    styleValues.fgColor = fgColor;
 	    fgPrio = tagPtr->priority;
 	}
@@ -931,9 +931,9 @@ GetStyle(
 		&& (tagPtr->priority > overstrikePrio)) {
 	    styleValues.overstrike = tagPtr->overstrike;
 	    overstrikePrio = tagPtr->priority;
-            if (tagPtr->overstrikeColor) {
+            if (tagPtr->overstrikeColor != None) {
                  styleValues.overstrikeColor = tagPtr->overstrikeColor;
-            } else if (fgColor) {
+            } else if (fgColor != None) {
                  styleValues.overstrikeColor = fgColor;
             }
 	}
@@ -976,9 +976,9 @@ GetStyle(
 		&& (tagPtr->priority > underlinePrio)) {
 	    styleValues.underline = tagPtr->underline;
 	    underlinePrio = tagPtr->priority;
-            if (tagPtr->underlineColor) {
+            if (tagPtr->underlineColor != None) {
                  styleValues.underlineColor = tagPtr->underlineColor;
-            } else if (fgColor) {
+            } else if (fgColor != None) {
                  styleValues.underlineColor = fgColor;
             }
 	}
@@ -1025,7 +1025,7 @@ GetStyle(
 	}
 	stylePtr->bgGC = Tk_GetGC(textPtr->tkwin, mask, &gcValues);
     } else {
-	stylePtr->bgGC = NULL;
+	stylePtr->bgGC = None;
     }
     mask = GCFont;
     gcValues.font = Tk_FontId(styleValues.tkfont);
@@ -1082,10 +1082,10 @@ FreeStyle(
 	if (stylePtr->fgGC != None) {
 	    Tk_FreeGC(textPtr->display, stylePtr->fgGC);
 	}
-	if (stylePtr->ulGC) {
+	if (stylePtr->ulGC != None) {
 	    Tk_FreeGC(textPtr->display, stylePtr->ulGC);
 	}
-	if (stylePtr->ovGC) {
+	if (stylePtr->ovGC != None) {
 	    Tk_FreeGC(textPtr->display, stylePtr->ovGC);
 	}
 	Tcl_DeleteHashEntry(stylePtr->hPtr);
diff --git a/generic/tkTextTag.c b/generic/tkTextTag.c
index 3a7052a..9ade3ad 100644
--- a/generic/tkTextTag.c
+++ b/generic/tkTextTag.c
@@ -534,10 +534,10 @@ TkTextTagCmd(
 	    if ((tagPtr->border != NULL)
 		    || (tagPtr->selBorder != NULL)
 		    || (tagPtr->reliefString != NULL)
-		    || tagPtr->bgStipple
+		    || (tagPtr->bgStipple != None)
 		    || (tagPtr->fgColor != NULL)
 		    || (tagPtr->selFgColor != NULL)
-		    || tagPtr->fgStipple
+		    || (tagPtr->fgStipple != None)
 		    || (tagPtr->overstrikeString != NULL)
                     || (tagPtr->overstrikeColor != NULL)
 		    || (tagPtr->underlineString != NULL)
diff --git a/generic/tkWindow.c b/generic/tkWindow.c
index 839e860..d175ef9 100644
--- a/generic/tkWindow.c
+++ b/generic/tkWindow.c
@@ -474,9 +474,9 @@ GetScreen(
 
 	    dispPtr->lastEventTime = CurrentTime;
 	    dispPtr->bindInfoStale = 1;
-	    dispPtr->cursorFont = 0;
+	    dispPtr->cursorFont = None;
 	    dispPtr->warpWindow = NULL;
-	    dispPtr->multipleAtom = 0;
+	    dispPtr->multipleAtom = None;
 
 	    /*
 	     * By default we do want to collapse motion events in
@@ -2088,7 +2088,7 @@ void
 Tk_UndefineCursor(
     Tk_Window tkwin)		/* Window to manipulate. */
 {
-    Tk_DefineCursor(tkwin, NULL);
+    Tk_DefineCursor(tkwin, None);
 }
 
 void
@@ -2357,7 +2357,7 @@ Tk_IdToWindow(
 	    break;
 	}
     }
-    if (!window) {
+    if (window == None) {
 	return NULL;
     }
 
diff --git a/generic/ttk/ttkEntry.c b/generic/ttk/ttkEntry.c
index a8bb717..f6a9c27 100644
--- a/generic/ttk/ttkEntry.c
+++ b/generic/ttk/ttkEntry.c
@@ -1265,7 +1265,7 @@ static void EntryDisplay(void *clientData, Drawable d)
 	    cursorX = field.x + field.width - cursorWidth;
 	}
 
-	gc = EntryGetGC(entryPtr, es.insertColorObj, 0);
+	gc = EntryGetGC(entryPtr, es.insertColorObj, None);
 	XFillRectangle(Tk_Display(tkwin), d, gc,
 	    cursorX, cursorY, cursorWidth, cursorHeight);
 	Tk_FreeGC(Tk_Display(tkwin), gc);
diff --git a/macosx/tkMacOSXDefault.h b/macosx/tkMacOSXDefault.h
index a0b6a79..b749673 100644
--- a/macosx/tkMacOSXDefault.h
+++ b/macosx/tkMacOSXDefault.h
@@ -37,7 +37,7 @@
 #define ACTIVE_BG		"systemButtonFacePressed"
 #define ACTIVE_FG		"systemPushButtonPressedText"
 #define SELECT_BG		"systemHighlight"
-#define SELECT_FG		NULL
+#define SELECT_FG		None
 #define INACTIVE_SELECT_BG	"systemHighlightSecondary"
 #define TROUGH			"#c3c3c3"
 #define INDICATOR		"#b03060"
@@ -282,7 +282,7 @@
 #define DEF_MENU_ENTRY_ACTIVE_FG	NULL
 #define DEF_MENU_ENTRY_ACCELERATOR	NULL
 #define DEF_MENU_ENTRY_BG		NULL
-#define DEF_MENU_ENTRY_BITMAP		NULL
+#define DEF_MENU_ENTRY_BITMAP		None
 #define DEF_MENU_ENTRY_COLUMN_BREAK	"0"
 #define DEF_MENU_ENTRY_COMMAND		NULL
 #define DEF_MENU_ENTRY_COMPOUND		"none"
diff --git a/macosx/tkMacOSXDialog.c b/macosx/tkMacOSXDialog.c
index fd1ec22..e828b39 100644
--- a/macosx/tkMacOSXDialog.c
+++ b/macosx/tkMacOSXDialog.c
@@ -1950,7 +1950,7 @@ FontchooserParentEventHandler(
     if (eventPtr->type == DestroyNotify) {
 	Tk_DeleteEventHandler(fcdPtr->parent, StructureNotifyMask,
 		FontchooserParentEventHandler, fcdPtr);
-	fcdPtr->parent = NULL;
+	fcdPtr->parent = None;
 	FontchooserHideCmd(NULL, NULL, 0, NULL);
     }
 }
diff --git a/macosx/tkMacOSXEmbed.c b/macosx/tkMacOSXEmbed.c
index 589475c..f6c32b3 100644
--- a/macosx/tkMacOSXEmbed.c
+++ b/macosx/tkMacOSXEmbed.c
@@ -494,7 +494,7 @@ TkMacOSXContainerId(
 	}
     }
     Tcl_Panic("TkMacOSXContainerId couldn't find window");
-    return NULL;
+    return None;
 }
 
 /*
@@ -530,8 +530,8 @@ TkMacOSXGetHostToplevel(
      * TODO: Here we should handle out of process embedding.
      */
 
-    if (!contWinPtr) {
-	return NULL;
+    if (contWinPtr == NULL) {
+	return None;
     }
     return TkMacOSXGetHostToplevel(contWinPtr);
 }
diff --git a/macosx/tkMacOSXMenu.c b/macosx/tkMacOSXMenu.c
index 8f3be9f..ec32a78 100644
--- a/macosx/tkMacOSXMenu.c
+++ b/macosx/tkMacOSXMenu.c
@@ -1481,10 +1481,10 @@ TkpMenuInit(void)
 #undef observe
 
     [NSMenuItem setUsesUserKeyEquivalents:NO];
-    tkColPtr = TkpGetColor(NULL, DEF_MENU_BG_COLOR);
+    tkColPtr = TkpGetColor(None, DEF_MENU_BG_COLOR);
     defaultBg = tkColPtr->color.pixel;
     ckfree(tkColPtr);
-    tkColPtr = TkpGetColor(NULL, DEF_MENU_FG);
+    tkColPtr = TkpGetColor(None, DEF_MENU_FG);
     defaultFg = tkColPtr->color.pixel;
     ckfree(tkColPtr);
 
diff --git a/macosx/tkMacOSXScrlbr.c b/macosx/tkMacOSXScrlbr.c
index 688829d..d1287bb 100644
--- a/macosx/tkMacOSXScrlbr.c
+++ b/macosx/tkMacOSXScrlbr.c
@@ -119,8 +119,8 @@ TkpCreateScrollbar(
 
     MacScrollbar *scrollPtr = (MacScrollbar *)ckalloc(sizeof(MacScrollbar));
 
-    scrollPtr->troughGC = NULL;
-    scrollPtr->copyGC = NULL;
+    scrollPtr->troughGC = None;
+    scrollPtr->copyGC = None;
     scrollPtr->info = defaultInfo;
     scrollPtr->buttonDown = false;
     
diff --git a/unix/tkUnix3d.c b/unix/tkUnix3d.c
index 58004d9..038d4e1 100644
--- a/unix/tkUnix3d.c
+++ b/unix/tkUnix3d.c
@@ -48,7 +48,7 @@ TkpGetBorder(void)
 {
     UnixBorder *borderPtr = ckalloc(sizeof(UnixBorder));
 
-    borderPtr->solidGC = NULL;
+    borderPtr->solidGC = None;
     return (TkBorder *) borderPtr;
 }
 
@@ -216,7 +216,7 @@ Tk_3DHorizontalBevel(
     Display *display = Tk_Display(tkwin);
     int bottom, halfway, x1, x2, x1Delta, x2Delta;
     UnixBorder *unixBorderPtr = (UnixBorder *) borderPtr;
-    GC topGC = NULL, bottomGC = NULL;
+    GC topGC = None, bottomGC = None;
 				/* Initializations needed only to prevent
 				 * compiler warnings. */
 
diff --git a/unix/tkUnixDefault.h b/unix/tkUnixDefault.h
index 21f6276..2c3854d 100644
--- a/unix/tkUnixDefault.h
+++ b/unix/tkUnixDefault.h
@@ -244,7 +244,7 @@
 #define DEF_MENU_ENTRY_ACTIVE_FG	((char *) NULL)
 #define DEF_MENU_ENTRY_ACCELERATOR	((char *) NULL)
 #define DEF_MENU_ENTRY_BG		((char *) NULL)
-#define DEF_MENU_ENTRY_BITMAP		NULL
+#define DEF_MENU_ENTRY_BITMAP		None
 #define DEF_MENU_ENTRY_COLUMN_BREAK	"0"
 #define DEF_MENU_ENTRY_COMMAND		((char *) NULL)
 #define DEF_MENU_ENTRY_COMPOUND 	"none"
diff --git a/unix/tkUnixMenubu.c b/unix/tkUnixMenubu.c
index 6cb80f4..ad71b7b 100644
--- a/unix/tkUnixMenubu.c
+++ b/unix/tkUnixMenubu.c
@@ -92,10 +92,10 @@ TkpDisplayMenuButton(
 	border = mbPtr->normalBorder;
     }
 
-    if (mbPtr->image) {
+    if (mbPtr->image != None) {
 	Tk_SizeOfImage(mbPtr->image, &width, &height);
 	haveImage = 1;
-    } else if (mbPtr->bitmap) {
+    } else if (mbPtr->bitmap != None) {
 	Tk_SizeOfBitmap(mbPtr->display, mbPtr->bitmap, &width, &height);
 	haveImage = 1;
     }
@@ -183,7 +183,7 @@ TkpDisplayMenuButton(
 	if (mbPtr->image != NULL) {
 	    Tk_RedrawImage(mbPtr->image, 0, 0, width, height, pixmap,
 		    imageXOffset, imageYOffset);
-	} else if (mbPtr->bitmap) {
+	} else if (mbPtr->bitmap != None) {
 	    XSetClipOrigin(mbPtr->display, gc, imageXOffset, imageYOffset);
 	    XCopyPlane(mbPtr->display, mbPtr->bitmap, pixmap,
 		    gc, 0, 0, (unsigned) width, (unsigned) height,
@@ -203,7 +203,7 @@ TkpDisplayMenuButton(
 	if (mbPtr->image != NULL) {
 	    Tk_RedrawImage(mbPtr->image, 0, 0, width, height, pixmap,
 		    imageXOffset, imageYOffset);
-	} else if (mbPtr->bitmap) {
+	} else if (mbPtr->bitmap != None) {
 	    XSetClipOrigin(mbPtr->display, gc, x, y);
 	    XCopyPlane(mbPtr->display, mbPtr->bitmap, pixmap,
 		    gc, 0, 0, (unsigned) width, (unsigned) height,
@@ -358,10 +358,10 @@ TkpComputeMenuButtonGeometry(
     txtHeight = 0;
     avgWidth = 0;
 
-    if (mbPtr->image) {
+    if (mbPtr->image != None) {
 	Tk_SizeOfImage(mbPtr->image, &width, &height);
 	haveImage = 1;
-    } else if (mbPtr->bitmap) {
+    } else if (mbPtr->bitmap != None) {
 	Tk_SizeOfBitmap(mbPtr->display, mbPtr->bitmap, &width, &height);
 	haveImage = 1;
     }
diff --git a/win/stubs.c b/win/stubs.c
index 24df27c..1cf23ef 100644
--- a/win/stubs.c
+++ b/win/stubs.c
@@ -397,7 +397,7 @@ XGetWindowProperty(
     unsigned long *bytes_after_return,
     unsigned char **prop_return)
 {
-    *actual_type_return = 0;
+    *actual_type_return = None;
     *actual_format_return = 0;
     *nitems_return = 0;
     *bytes_after_return = 0;
diff --git a/win/tkWin3d.c b/win/tkWin3d.c
index bf7a539..d3c443d 100644
--- a/win/tkWin3d.c
+++ b/win/tkWin3d.c
@@ -127,7 +127,7 @@ Tk_3DVerticalBevel(
     HDC dc = TkWinGetDrawableDC(display, drawable, &state);
     int half;
 
-    if (!borderPtr->lightGC && (relief != TK_RELIEF_FLAT)) {
+    if ((borderPtr->lightGC == None) && (relief != TK_RELIEF_FLAT)) {
 	TkpGetShadows(borderPtr, tkwin);
     }
 
@@ -222,7 +222,7 @@ Tk_3DHorizontalBevel(
     HDC dc = TkWinGetDrawableDC(display, drawable, &state);
     int topColor, bottomColor;
 
-    if (!borderPtr->lightGC && (relief != TK_RELIEF_FLAT)) {
+    if ((borderPtr->lightGC == None) && (relief != TK_RELIEF_FLAT)) {
 	TkpGetShadows(borderPtr, tkwin);
     }
 
@@ -339,7 +339,7 @@ TkpGetShadows(
     int r, g, b;
     XGCValues gcValues;
 
-    if (borderPtr->lightGC) {
+    if (borderPtr->lightGC != None) {
 	return;
     }
 
@@ -465,10 +465,10 @@ TkpGetShadows(
 	return;
     }
 
-    if (!borderPtr->shadow) {
+    if (borderPtr->shadow == None) {
 	borderPtr->shadow = Tk_GetBitmap((Tcl_Interp *) NULL, tkwin,
 		Tk_GetUid("gray50"));
-	if (!borderPtr->shadow) {
+	if (borderPtr->shadow == None) {
 	    Tcl_Panic("TkpGetShadows couldn't allocate bitmap for border");
 	}
     }
@@ -540,7 +540,7 @@ TkWinGetBorderPixels(
 {
     WinBorder *borderPtr = (WinBorder *) border;
 
-    if (!borderPtr->info.lightGC) {
+    if (borderPtr->info.lightGC == None) {
 	TkpGetShadows(&borderPtr->info, tkwin);
     }
     switch (which) {
diff --git a/win/tkWinButton.c b/win/tkWinButton.c
index 32c2499..e46bcb3 100644
--- a/win/tkWinButton.c
+++ b/win/tkWinButton.c
@@ -433,10 +433,10 @@ TkpDisplayButton(
      * Display image or bitmap or text for button.
      */
 
-    if (butPtr->image) {
+    if (butPtr->image != None) {
 	Tk_SizeOfImage(butPtr->image, &width, &height);
 	haveImage = 1;
-    } else if (butPtr->bitmap) {
+    } else if (butPtr->bitmap != None) {
 	Tk_SizeOfBitmap(butPtr->display, butPtr->bitmap, &width, &height);
 	haveImage = 1;
     }
@@ -839,7 +839,7 @@ TkpComputeButtonGeometry(
     if (butPtr->image != NULL) {
 	Tk_SizeOfImage(butPtr->image, &imgWidth, &imgHeight);
 	haveImage = 1;
-    } else if (butPtr->bitmap) {
+    } else if (butPtr->bitmap != None) {
 	Tk_SizeOfBitmap(butPtr->display, butPtr->bitmap,
 		&imgWidth, &imgHeight);
 	haveImage = 1;
diff --git a/win/tkWinDefault.h b/win/tkWinDefault.h
index 028c204..f389075 100644
--- a/win/tkWinDefault.h
+++ b/win/tkWinDefault.h
@@ -247,7 +247,7 @@
 #define DEF_MENU_ENTRY_ACTIVE_FG	((char *) NULL)
 #define DEF_MENU_ENTRY_ACCELERATOR	((char *) NULL)
 #define DEF_MENU_ENTRY_BG		((char *) NULL)
-#define DEF_MENU_ENTRY_BITMAP		NULL
+#define DEF_MENU_ENTRY_BITMAP		None
 #define DEF_MENU_ENTRY_COLUMN_BREAK	"0"
 #define DEF_MENU_ENTRY_COMMAND		((char *) NULL)
 #define DEF_MENU_ENTRY_COMPOUND 	"none"
diff --git a/win/tkWinDialog.c b/win/tkWinDialog.c
index 6795ef3..d6d2c7d 100644
--- a/win/tkWinDialog.c
+++ b/win/tkWinDialog.c
@@ -3351,7 +3351,7 @@ FontchooserConfigureCmd(
 	    Tk_Window parent = Tk_NameToWindow(interp,
 		    Tcl_GetString(objv[i+1]), tkwin);
 
-	    if (!parent) {
+	    if (parent == None) {
 		return TCL_ERROR;
 	    }
 	    if (hdPtr->parentObj) {
@@ -3446,7 +3446,7 @@ FontchooserShowCmd(
     if (hdPtr->parentObj) {
 	parent = Tk_NameToWindow(interp, Tcl_GetString(hdPtr->parentObj),
 		tkwin);
-	if (!parent) {
+	if (parent == None) {
 	    return TCL_ERROR;
 	}
     }
diff --git a/win/tkWinDraw.c b/win/tkWinDraw.c
index 2c35d3b..e13a5e5 100644
--- a/win/tkWinDraw.c
+++ b/win/tkWinDraw.c
@@ -644,7 +644,7 @@ XFillRectangles(
     TkWinDCState state;
     HBRUSH brush, oldBrush;
 
-    if (!d) {
+    if (d == None) {
 	return BadDrawable;
     }
 
@@ -654,7 +654,7 @@ XFillRectangles(
 
     if ((gc->fill_style == FillStippled
 	    || gc->fill_style == FillOpaqueStippled)
-	    && gc->stipple) {
+	    && gc->stipple != None) {
 	TkWinDrawable *twdPtr = (TkWinDrawable *)gc->stipple;
 	HBRUSH stipple;
 	HBITMAP oldBitmap, bitmap;
@@ -818,7 +818,7 @@ RenderObject(
 
     if ((gc->fill_style == FillStippled
 	    || gc->fill_style == FillOpaqueStippled)
-	    && gc->stipple) {
+	    && gc->stipple != None) {
 
 	TkWinDrawable *twdPtr = (TkWinDrawable *)gc->stipple;
 	HDC dcMem;
@@ -942,7 +942,7 @@ XDrawLines(
     TkWinDCState state;
     HDC dc;
 
-    if (!d) {
+    if (d == None) {
 	return BadDrawable;
     }
 
@@ -987,7 +987,7 @@ XFillPolygon(
     TkWinDCState state;
     HDC dc;
 
-    if (!d) {
+    if (d == None) {
 	return BadDrawable;
     }
 
@@ -1029,7 +1029,7 @@ XDrawRectangle(
     HBRUSH oldBrush;
     HDC dc;
 
-    if (!d) {
+    if (d == None) {
 	return BadDrawable;
     }
 
@@ -1214,7 +1214,7 @@ DrawOrFillArc(
     int xstart, ystart, xend, yend;
     double radian_start, radian_end, xr, yr;
 
-    if (!d) {
+    if (d == None) {
 	return BadDrawable;
     }
 
diff --git a/win/tkWinEmbed.c b/win/tkWinEmbed.c
index 25bb6f8..43c5e25 100644
--- a/win/tkWinEmbed.c
+++ b/win/tkWinEmbed.c
@@ -242,7 +242,7 @@ TkpUseWindow(
 */
 
 /*
-    if (winPtr->window) {
+    if (winPtr->window != None) {
 	Tcl_SetObjResult(interp, Tcl_NewStringObj(
 		"can't modify container after widget is created", -1));
 	Tcl_SetErrorCode(interp, "TK", "EMBED", "POST_CREATE", NULL);
diff --git a/win/tkWinFont.c b/win/tkWinFont.c
index 977086b..d67ea66 100644
--- a/win/tkWinFont.c
+++ b/win/tkWinFont.c
@@ -519,7 +519,7 @@ TkpGetFontFromAttributes(
 
     tkwin = (Tk_Window) ((TkWindow *) tkwin)->mainPtr->winPtr;
     window = Tk_WindowId(tkwin);
-    hwnd = window ? TkWinGetHWND(window) : NULL;
+    hwnd = (window == None) ? NULL : TkWinGetHWND(window);
     hdc = GetDC(hwnd);
 
     /*
@@ -632,7 +632,7 @@ TkpGetFontFamilies(
     Tcl_Obj *resultObj;
 
     window = Tk_WindowId(tkwin);
-    hwnd = window ? TkWinGetHWND(window) : NULL;
+    hwnd = (window == None) ? NULL : TkWinGetHWND(window);
     hdc = GetDC(hwnd);
     resultObj = Tcl_NewObj();
 
@@ -1089,7 +1089,7 @@ Tk_DrawChars(
     fontPtr = (WinFont *) gc->font;
     display->request++;
 
-    if (!drawable) {
+    if (drawable == None) {
 	return;
     }
 
@@ -1097,14 +1097,14 @@ Tk_DrawChars(
 
     SetROP2(dc, tkpWinRopModes[gc->function]);
 
-    if (gc->clip_mask &&
+    if ((gc->clip_mask != None) &&
 	    ((TkpClipMask *) gc->clip_mask)->type == TKP_CLIP_REGION) {
 	SelectClipRgn(dc, (HRGN)((TkpClipMask *)gc->clip_mask)->value.region);
     }
 
     if ((gc->fill_style == FillStippled
 	    || gc->fill_style == FillOpaqueStippled)
-	    && gc->stipple) {
+	    && gc->stipple != None) {
 	TkWinDrawable *twdPtr = (TkWinDrawable *) gc->stipple;
 	HBRUSH oldBrush, stipple;
 	HBITMAP oldBitmap, bitmap;
@@ -1237,7 +1237,7 @@ TkDrawAngledChars(
     fontPtr = (WinFont *) gc->font;
     display->request++;
 
-    if (!drawable) {
+    if (drawable == None) {
 	return;
     }
 
@@ -1245,14 +1245,14 @@ TkDrawAngledChars(
 
     SetROP2(dc, tkpWinRopModes[gc->function]);
 
-    if (gc->clip_mask &&
+    if ((gc->clip_mask != None) &&
 	    ((TkpClipMask *) gc->clip_mask)->type == TKP_CLIP_REGION) {
 	SelectClipRgn(dc, (HRGN)((TkpClipMask *)gc->clip_mask)->value.region);
     }
 
     if ((gc->fill_style == FillStippled
 	    || gc->fill_style == FillOpaqueStippled)
-	    && gc->stipple) {
+	    && gc->stipple != None) {
 	TkWinDrawable *twdPtr = (TkWinDrawable *)gc->stipple;
 	HBRUSH oldBrush, stipple;
 	HBITMAP oldBitmap, bitmap;
@@ -1568,7 +1568,7 @@ InitFont(
     TCHAR buf[LF_FACESIZE];
 
     window = Tk_WindowId(tkwin);
-    hwnd = window ? TkWinGetHWND(window) : NULL;
+    hwnd = (window == None) ? NULL : TkWinGetHWND(window);
     hdc = GetDC(hwnd);
     oldFont = SelectObject(hdc, hFont);
 
diff --git a/win/tkWinMenu.c b/win/tkWinMenu.c
index b03cf6d..a409764 100644
--- a/win/tkWinMenu.c
+++ b/win/tkWinMenu.c
@@ -2364,7 +2364,7 @@ DrawMenuEntryLabel(
 	    XFillRectangle(menuPtr->display, d, menuPtr->disabledGC, x, y,
 		    (unsigned) width, (unsigned) height);
 	} else if ((mePtr->image != NULL)
-		&& menuPtr->disabledImageGC) {
+		&& (menuPtr->disabledImageGC != None)) {
 	    XFillRectangle(menuPtr->display, d, menuPtr->disabledImageGC,
 		    leftEdge + imageXOffset,
 		    (int) (y + (mePtr->height - imageHeight)/2 + imageYOffset),
@@ -3005,7 +3005,7 @@ MenuSelectEvent(
     Tk_MakeWindowExist(menuPtr->tkwin);
     event.event = Tk_WindowId(menuPtr->tkwin);
     event.root = XRootWindow(menuPtr->display, 0);
-    event.subwindow = 0;
+    event.subwindow = None;
     event.time = TkpGetMS();
 
     root.msgpos = GetMessagePos();
diff --git a/win/tkWinPixmap.c b/win/tkWinPixmap.c
index a45a322..aa1ebde 100644
--- a/win/tkWinPixmap.c
+++ b/win/tkWinPixmap.c
@@ -115,7 +115,7 @@ Tk_GetPixmap(
 
     if (newTwdPtr->bitmap.handle == NULL) {
 	ckfree(newTwdPtr);
-	return 0;
+	return None;
     }
 
     return (Pixmap) newTwdPtr;
diff --git a/win/tkWinPointer.c b/win/tkWinPointer.c
index 869c059..6f1f840 100644
--- a/win/tkWinPointer.c
+++ b/win/tkWinPointer.c
@@ -401,7 +401,7 @@ XGetInputFocus(
 {
     Tk_Window tkwin = Tk_HWNDToWindow(GetFocus());
 
-    *focus_return = tkwin ? Tk_WindowId(tkwin) : 0;
+    *focus_return = tkwin ? Tk_WindowId(tkwin) : None;
     *revert_to_return = RevertToParent;
     display->request++;
     return Success;
@@ -432,7 +432,7 @@ XSetInputFocus(
     Time time)
 {
     display->request++;
-    if (focus) {
+    if (focus != None) {
 	SetFocus(Tk_GetHWND(focus));
     }
     return Success;
@@ -479,7 +479,7 @@ TkpChangeFocus(
 	}
     }
 
-    if (!winPtr->window) {
+    if (winPtr->window == None) {
 	Tcl_Panic("ChangeXFocus got null X window");
     }
 
diff --git a/win/tkWinPort.h b/win/tkWinPort.h
index d9e7812..965dbc5 100644
--- a/win/tkWinPort.h
+++ b/win/tkWinPort.h
@@ -117,7 +117,7 @@
  */
 
 #define TkpDefineNativeBitmaps()
-#define TkpCreateNativeBitmap(display, source) 0
-#define TkpGetNativeAppBitmap(display, name, w, h) 0
+#define TkpCreateNativeBitmap(display, source) None
+#define TkpGetNativeAppBitmap(display, name, w, h) None
 
 #endif /* _WINPORT */
diff --git a/win/tkWinScrlbr.c b/win/tkWinScrlbr.c
index 5393054..1b3717e 100644
--- a/win/tkWinScrlbr.c
+++ b/win/tkWinScrlbr.c
@@ -237,7 +237,7 @@ CreateProc(
 
     for (winPtr = ((TkWindow*)tkwin)->nextPtr; winPtr != NULL;
 	    winPtr = winPtr->nextPtr) {
-	if ((winPtr->window) && !(winPtr->flags & TK_TOP_HIERARCHY)) {
+	if ((winPtr->window != None) && !(winPtr->flags & TK_TOP_HIERARCHY)) {
 	    TkWinSetWindowPos(scrollPtr->hwnd, Tk_GetHWND(winPtr->window),
 		    Below);
 	    break;
diff --git a/win/tkWinWindow.c b/win/tkWinWindow.c
index d037f07..385e72b 100644
--- a/win/tkWinWindow.c
+++ b/win/tkWinWindow.c
@@ -233,7 +233,7 @@ TkpScanWindowId(
     if (tkwin) {
 	*idPtr = Tk_WindowId(tkwin);
     } else {
-	*idPtr = 0;
+	*idPtr = None;
     }
     return TCL_OK;
 }
@@ -264,7 +264,7 @@ TkpMakeWindow(
     int style;
     HWND hwnd;
 
-    if (parent) {
+    if (parent != None) {
 	parentWin = Tk_GetHWND(parent);
 	style = WS_CHILD | WS_CLIPCHILDREN | WS_CLIPSIBLINGS;
     } else {
@@ -674,7 +674,7 @@ XConfigureWindow(
     if (valueMask & CWStackMode) {
 	HWND sibling;
 
-	if ((valueMask & CWSibling) && values->sibling) {
+	if ((valueMask & CWSibling) && (values->sibling != None)) {
 	    sibling = Tk_GetHWND(values->sibling);
 	} else {
 	    sibling = NULL;
diff --git a/win/tkWinWm.c b/win/tkWinWm.c
index 7c73094..4e7618d 100644
--- a/win/tkWinWm.c
+++ b/win/tkWinWm.c
@@ -978,7 +978,7 @@ WinSetIcon(
 		NULL);
 	return TCL_ERROR;
     }
-    if (!Tk_WindowId(tkw)) {
+    if (Tk_WindowId(tkw) == None) {
 	Tk_MakeWindowExist(tkw);
     }
 
@@ -1144,7 +1144,7 @@ TkWinGetIcon(
 	}
     }
 
-    if (!Tk_WindowId(tkwin)) {
+    if (Tk_WindowId(tkwin) == None) {
 	Tk_MakeWindowExist(tkwin);
     }
 
@@ -1922,11 +1922,11 @@ TkWmNewWindow(
     wmPtr->hints.flags = InputHint | StateHint;
     wmPtr->hints.input = True;
     wmPtr->hints.initial_state = NormalState;
-    wmPtr->hints.icon_pixmap = 0;
-    wmPtr->hints.icon_window = 0;
+    wmPtr->hints.icon_pixmap = None;
+    wmPtr->hints.icon_window = None;
     wmPtr->hints.icon_x = wmPtr->hints.icon_y = 0;
-    wmPtr->hints.icon_mask = 0;
-    wmPtr->hints.window_group = 0;
+    wmPtr->hints.icon_mask = None;
+    wmPtr->hints.window_group = None;
 
     /*
      * Default the maximum dimensions to the size of the display.
@@ -2007,7 +2007,7 @@ UpdateWrapper(
     ThreadSpecificData *tsdPtr =
 	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
 
-    if (!winPtr->window) {
+    if (winPtr->window == None) {
 	/*
 	 * Ensure existence of the window to update the wrapper for.
 	 */
@@ -2625,7 +2625,7 @@ TkWmDeadWindow(
 		    VisibilityChangeMask|StructureNotifyMask,
 		    WmWaitVisibilityOrMapProc, wmPtr2->winPtr);
 	    wmPtr2->masterPtr = NULL;
-	    if (wmPtr2->wrapper
+	    if ((wmPtr2->wrapper != None)
 		    && !(wmPtr2->flags & (WM_NEVER_MAPPED))) {
 		UpdateWrapper(wmPtr2->winPtr);
 	    }
@@ -3433,7 +3433,7 @@ WmColormapwindowsCmd(
 	if (winPtr2 == winPtr) {
 	    gotToplevel = 1;
 	}
-	if (!winPtr2->window) {
+	if (winPtr2->window == None) {
 	    Tk_MakeWindowExist((Tk_Window) winPtr2);
 	}
 	cmapList[i] = winPtr2;
@@ -3721,7 +3721,7 @@ WmFrameCmd(
 	Tcl_WrongNumArgs(interp, 2, objv, "window");
 	return TCL_ERROR;
     }
-    if (!Tk_WindowId((Tk_Window) winPtr)) {
+    if (Tk_WindowId((Tk_Window) winPtr) == None) {
 	Tk_MakeWindowExist((Tk_Window) winPtr);
     }
     hwnd = wmPtr->wrapper;
@@ -4023,9 +4023,9 @@ WmIconbitmapCmd(
 
     string = Tcl_GetString(objv[objc-1]);
     if (*string == '\0') {
-	if (wmPtr->hints.icon_pixmap) {
+	if (wmPtr->hints.icon_pixmap != None) {
 	    Tk_FreeBitmap(winPtr->display, wmPtr->hints.icon_pixmap);
-	    wmPtr->hints.icon_pixmap = 0;
+	    wmPtr->hints.icon_pixmap = None;
 	}
 	wmPtr->hints.flags &= ~IconPixmapHint;
 	if (WinSetIcon(interp, NULL, (Tk_Window) useWinPtr) != TCL_OK) {
@@ -4078,7 +4078,7 @@ WmIconbitmapCmd(
 
 	    Tcl_ResetResult(interp);
 	    pixmap = Tk_GetBitmap(interp, (Tk_Window) winPtr, string);
-	    if (!pixmap) {
+	    if (pixmap == None) {
 		return TCL_ERROR;
 	    }
 	    wmPtr->hints.icon_pixmap = pixmap;
@@ -4206,13 +4206,13 @@ WmIconmaskCmd(
     }
     argv3 = Tcl_GetString(objv[3]);
     if (*argv3 == '\0') {
-	if (wmPtr->hints.icon_mask) {
+	if (wmPtr->hints.icon_mask != None) {
 	    Tk_FreeBitmap(winPtr->display, wmPtr->hints.icon_mask);
 	}
 	wmPtr->hints.flags &= ~IconMaskHint;
     } else {
 	pixmap = Tk_GetBitmap(interp, tkwin, argv3);
-	if (!pixmap) {
+	if (pixmap == None) {
 	    return TCL_ERROR;
 	}
 	wmPtr->hints.icon_mask = pixmap;
@@ -6427,7 +6427,7 @@ Tk_GetRootCoords(
      * If the window is mapped, let Windows figure out the translation.
      */
 
-    if (winPtr->window) {
+    if (winPtr->window != None) {
 	HWND hwnd = Tk_GetHWND(winPtr->window);
 	POINT point;
 
@@ -6854,7 +6854,7 @@ TkWmRestackToplevel(
      * (mapping it may give it a reparent window).
      */
 
-    if (!winPtr->window) {
+    if (winPtr->window == None) {
 	Tk_MakeWindowExist((Tk_Window) winPtr);
     }
     if (winPtr->wmInfoPtr->flags & WM_NEVER_MAPPED) {
@@ -6864,7 +6864,7 @@ TkWmRestackToplevel(
 	? winPtr->wmInfoPtr->wrapper : Tk_GetHWND(winPtr->window);
 
     if (otherPtr != NULL) {
-	if (!otherPtr->window) {
+	if (otherPtr->window == None) {
 	    Tk_MakeWindowExist((Tk_Window) otherPtr);
 	}
 	if (otherPtr->wmInfoPtr->flags & WM_NEVER_MAPPED) {
@@ -6915,7 +6915,7 @@ TkWmAddToColormapWindows(
     TkWindow **oldPtr, **newPtr;
     int count, i;
 
-    if (!winPtr->window) {
+    if (winPtr->window == None) {
 	return;
     }
 
@@ -7350,7 +7350,7 @@ GenerateConfigureNotify(
     event.xconfigure.y = winPtr->changes.y;
     event.xconfigure.width = winPtr->changes.width;
     event.xconfigure.height = winPtr->changes.height;
-    event.xconfigure.above = 0;
+    event.xconfigure.above = None;
     Tk_QueueWindowEvent(&event, TCL_QUEUE_TAIL);
 }
 
@@ -8623,7 +8623,7 @@ TkpWinToplevelDetachWindow(
 	SendMessage(wmPtr->wrapper, TK_DETACHWINDOW, 0, 0);
 	winPtr->flags &= ~TK_EMBEDDED;
 	winPtr->privatePtr = NULL;
-	wmPtr->wrapper = 0;
+	wmPtr->wrapper = None;
 	if (state >= 0 && state <= 3) {
 	    wmPtr->hints.initial_state = state;
 	}
diff --git a/win/tkWinX.c b/win/tkWinX.c
index 661be57..a217108 100644
--- a/win/tkWinX.c
+++ b/win/tkWinX.c
@@ -522,10 +522,10 @@ TkWinDisplayChanged(
     screen->root_visual->bits_per_rgb = screen->root_depth;
     ReleaseDC(NULL, dc);
 
-    if (screen->cmap) {
+    if (screen->cmap != None) {
 	XFreeColormap(display, screen->cmap);
     }
-    screen->cmap = XCreateColormap(display, 0, screen->root_visual,
+    screen->cmap = XCreateColormap(display, None, screen->root_visual,
 	    AllocNone);
 }
 
@@ -585,7 +585,7 @@ TkpOpenDisplay(
 
     twdPtr = ckalloc(sizeof(TkWinDrawable));
     if (twdPtr == NULL) {
-	return 0;
+	return None;
     }
     twdPtr->type = TWD_WINDOW;
     twdPtr->window.winPtr = NULL;
@@ -598,7 +598,7 @@ TkpOpenDisplay(
 
     screen->white_pixel = RGB(255, 255, 255);
     screen->black_pixel = RGB(0, 0, 0);
-    screen->cmap = 0;
+    screen->cmap = None;
 
     display->screens		= screen;
     display->nscreens		= 1;
@@ -655,10 +655,10 @@ TkpCloseDisplay(
 	if (display->screens->root_visual != NULL) {
 	    ckfree(display->screens->root_visual);
 	}
-	if (display->screens->root) {
+	if (display->screens->root != None) {
 	    ckfree(display->screens->root);
 	}
-	if (display->screens->cmap) {
+	if (display->screens->cmap != None) {
 	    XFreeColormap(display, display->screens->cmap);
 	}
 	ckfree(display->screens);
@@ -998,7 +998,7 @@ GenerateXEvent(
     }
 
     winPtr = (TkWindow *) Tk_HWNDToWindow(hwnd);
-    if (!winPtr || !winPtr->window) {
+    if (!winPtr || winPtr->window == None) {
 	return;
     }
 
@@ -1121,7 +1121,7 @@ GenerateXEvent(
 	 */
 
 	event.xbutton.root = RootWindow(winPtr->display, winPtr->screenNum);
-	event.xbutton.subwindow = 0;
+	event.xbutton.subwindow = None;
 	event.xbutton.x = clientPoint.x;
 	event.xbutton.y = clientPoint.y;
 	event.xbutton.x_root = root.point.x;
@@ -1623,7 +1623,7 @@ HandleIMEComposition(
 	event.xkey.display = winPtr->display;
 	event.xkey.window = winPtr->window;
 	event.xkey.root = RootWindow(winPtr->display, winPtr->screenNum);
-	event.xkey.subwindow = 0;
+	event.xkey.subwindow = None;
 	event.xkey.state = TkWinGetModifierState();
 	event.xkey.time = TkpGetMS();
 	event.xkey.same_screen = True;
diff --git a/win/ttkWinXPTheme.c b/win/ttkWinXPTheme.c
index de207ad..3de1504 100644
--- a/win/ttkWinXPTheme.c
+++ b/win/ttkWinXPTheme.c
@@ -455,7 +455,7 @@ InitElementData(ElementData *elementData, Tk_Window tkwin, Drawable d)
 {
     Window win = Tk_WindowId(tkwin);
 
-    if (win) {
+    if (win != None) {
 	elementData->hwnd = Tk_GetHWND(win);
     } else  {
 	elementData->hwnd = elementData->procs->stubWindow;
diff --git a/xlib/X11/X.h b/xlib/X11/X.h
index 316683b..daf2283 100644
--- a/xlib/X11/X.h
+++ b/xlib/X11/X.h
@@ -73,7 +73,7 @@ typedef unsigned long KeyCode;	/* In order to use IME, the Macintosh needs
  * RESERVED RESOURCE AND CONSTANT DEFINITIONS
  *****************************************************************/
 
-/* define None              0L      See bug [9e31fd9449] and below */
+#define None                 0L	/* universal null resource or null atom */
 
 #define ParentRelative       1L	/* background pixmap in CreateWindow
 				    and ChangeWindowAttributes */
@@ -179,16 +179,13 @@ are reserved in the protocol for errors and replies. */
 
 #define ShiftMask		(1<<0)
 #define LockMask		(1<<1)
-/* define ControlMask		(1<<2) See bug [9e31fd9449] and below */
+#define ControlMask		(1<<2)
 #define Mod1Mask		(1<<3)
 #define Mod2Mask		(1<<4)
 #define Mod3Mask		(1<<5)
 #define Mod4Mask		(1<<6)
 #define Mod5Mask		(1<<7)
 
-/* See bug [9e31fd9449], this way prevents conflicts with Win32 headers */
-enum _Bug9e31fd9449 { None = 0, ControlMask = (1<<2) };
-
 /* modifier names.  Used to build a SetModifierMapping request or
    to read a GetModifierMapping request.  These correspond to the
    masks defined above. */
@@ -297,7 +294,7 @@ enum _Bug9e31fd9449 { None = 0, ControlMask = (1<<2) };
 
 /* Used in SetInputFocus, GetInputFocus */
 
-#define RevertToNone		0
+#define RevertToNone		(int)None
 #define RevertToPointerRoot	(int)PointerRoot
 #define RevertToParent		2
 
diff --git a/xlib/xgc.c b/xlib/xgc.c
index be66b21..984c949 100644
--- a/xlib/xgc.c
+++ b/xlib/xgc.c
@@ -50,7 +50,7 @@
 static TkpClipMask *AllocClipMask(GC gc) {
     TkpClipMask *clip_mask = (TkpClipMask*) gc->clip_mask;
 
-    if (!clip_mask) {
+    if (clip_mask == None) {
 	clip_mask = ckalloc(sizeof(TkpClipMask));
 	gc->clip_mask = (Pixmap) clip_mask;
 #ifdef MAC_OSX_TK
@@ -78,14 +78,14 @@ static TkpClipMask *AllocClipMask(GC gc) {
  */
 
 static void FreeClipMask(GC gc) {
-    if (gc->clip_mask) {
+    if (gc->clip_mask != None) {
 #ifdef MAC_OSX_TK
 	if (((TkpClipMask*) gc->clip_mask)->type == TKP_CLIP_REGION) {
 	    TkpReleaseRegion(((TkpClipMask*) gc->clip_mask)->value.region);
 	}
 #endif
 	ckfree(gc->clip_mask);
-	gc->clip_mask = 0;
+	gc->clip_mask = None;
     }
 }
 
@@ -125,7 +125,7 @@ XCreateGC(
 
     gp = ckalloc(sizeof(XGCValues) + MAX_DASH_LIST_SIZE + gcCacheSize);
     if (!gp) {
-	return 0;
+	return None;
     }
 
 #define InitField(name,maskbit,default) \
@@ -144,11 +144,11 @@ XCreateGC(
     InitField(fill_style,	  GCFillStyle,		FillSolid);
     InitField(fill_rule,	  GCFillRule,		WindingRule);
     InitField(arc_mode,		  GCArcMode,		ArcPieSlice);
-    InitField(tile,		  GCTile,		0);
-    InitField(stipple,		  GCStipple,		0);
+    InitField(tile,		  GCTile,		None);
+    InitField(stipple,		  GCStipple,		None);
     InitField(ts_x_origin,	  GCTileStipXOrigin,	0);
     InitField(ts_y_origin,	  GCTileStipYOrigin,	0);
-    InitField(font,		  GCFont,		0);
+    InitField(font,		  GCFont,		None);
     InitField(subwindow_mode,	  GCSubwindowMode,	ClipByChildren);
     InitField(graphics_exposures, GCGraphicsExposures,	True);
     InitField(clip_x_origin,	  GCClipXOrigin,	0);
@@ -157,7 +157,7 @@ XCreateGC(
     InitField(dashes,		  GCDashList,		4);
     (&(gp->dashes))[1] = 0;
 
-    gp->clip_mask = 0;
+    gp->clip_mask = None;
     if (mask & GCClipMask) {
 	TkpClipMask *clip_mask = AllocClipMask(gp);
 
@@ -268,7 +268,7 @@ int XFreeGC(
     Display *d,
     GC gc)
 {
-    if (gc) {
+    if (gc != None) {
 	FreeClipMask(gc);
 	TkpFreeGCCache(gc);
 	ckfree(gc);
@@ -464,7 +464,7 @@ TkSetRegion(
     GC gc,
     TkRegion r)
 {
-    if (!r) {
+    if (r == None) {
 	Tcl_Panic("must not pass None to TkSetRegion for compatibility with X11; use XSetClipMask instead");
     } else {
 	TkpClipMask *clip_mask = AllocClipMask(gc);
@@ -483,7 +483,7 @@ XSetClipMask(
     GC gc,
     Pixmap pixmap)
 {
-    if (!pixmap) {
+    if (pixmap == None) {
 	FreeClipMask(gc);
     } else {
 	TkpClipMask *clip_mask = AllocClipMask(gc);
diff --git a/xlib/ximage.c b/xlib/ximage.c
index f7bf1cc..aaab946 100644
--- a/xlib/ximage.c
+++ b/xlib/ximage.c
@@ -47,7 +47,7 @@ XCreateBitmapFromData(
     pix = Tk_GetPixmap(display, d, (int) width, (int) height, 1);
     gc = XCreateGC(display, pix, 0, NULL);
     if (gc == NULL) {
-	return 0;
+	return None;
     }
     ximage = XCreateImage(display, NULL, 1, XYBitmap, 0, (char*) data, width,
 	    height, 8, (width + 7) / 8);