Index: macosx/tkMacOSXDraw.c
==================================================================
--- macosx/tkMacOSXDraw.c
+++ macosx/tkMacOSXDraw.c
@@ -1612,40 +1612,47 @@
     if (dc.context) {
 	dc.portBounds = clipBounds = CGContextGetClipBoundingBox(dc.context);
     } else if (win) {
 	NSView *view = TkMacOSXDrawableView(macDraw);
 
+	/*
+	 * We can only draw into the view when the current CGContext is
+	 * valid.  Starting with OSX 10.14, validity can only be guaranteed
+	 * inside of a view's drawRect or setFrame methods.  The isDrawing
+	 * attribute tells us whether we are being called from one of those
+	 * methods.
+	 *
+	 * If the CGContext is not valid then we mark our view as needing
+	 * display in the bounding rectangle of the clipping region and
+	 * return failure.  That rectangle should get drawn in a later call
+	 * to drawRect.
+	 */
+
 	if (!view) {
 	    Tcl_Panic("TkMacOSXSetupDrawingContext(): "
 		    "no NSView to draw into !");
 	}
-
-	/*
-	 * We can only draw into the view when the current CGContext is valid
-	 * and belongs to the view.  Validity can only be guaranteed inside of
-	 * a view's drawRect or setFrame methods.  The isDrawing attribute
-	 * tells us whether we are being called from one of those methods.
-	 *
-	 * If the CGContext is not valid, or belongs to a different View, then
-	 * we mark our view as needing display and return failure. It should
-	 * get drawn in a later call to drawRect.
-	 */
-
-	if (view != [NSView focusView]) {
-	    [view setNeedsDisplay:YES];
+	if (![NSApp isDrawing]) {
+	    NSRect bounds = [view bounds];
+	    NSRect dirtyNS = bounds;
+	    CGAffineTransform t = { .a = 1, .b = 0, .c = 0, .d = -1, .tx = 0,
+				    .ty = dirtyNS.size.height};
+	    if (dc.clipRgn) {
+		CGRect dirtyCG = NSRectToCGRect(dirtyNS);
+		HIShapeGetBounds(dc.clipRgn, &dirtyCG);
+		dirtyNS = NSRectToCGRect(CGRectApplyAffineTransform(dirtyCG, t));
+	    }
+	    [view setNeedsDisplayInRect:dirtyNS];
 	    canDraw = false;
 	    goto end;
 	}
 	dc.view = view;
 	dc.context = GET_CGCONTEXT;
 	dc.portBounds = NSRectToCGRect([view bounds]);
 	if (dc.clipRgn) {
 	    clipBounds = CGContextGetClipBoundingBox(dc.context);
 	}
-    } else {
-	Tcl_Panic("TkMacOSXSetupDrawingContext(): "
-		"no context to draw into !");
     }
 
     /*
      * Configure the drawing context.
      */

Index: macosx/tkMacOSXWindowEvent.c
==================================================================
--- macosx/tkMacOSXWindowEvent.c
+++ macosx/tkMacOSXWindowEvent.c
@@ -427,10 +427,17 @@
 	CFRelease(boundsRgn);
 	return 0;
     }
     HIShapeGetBounds(damageRgn, &damageBounds);
 
+    /*
+     * Expand the damage rectangle a bit to avoid artifacts when
+     * moving canvas items very quickly.
+     */
+
+    damageBounds = CGRectInset(damageBounds, -10, -10);
+
     CFRelease(damageRgn);
     CFRelease(boundsRgn);
 
     event.xany.serial = LastKnownRequestProcessed(Tk_Display(winPtr));
     event.xany.send_event = false;
@@ -452,26 +459,26 @@
     /*
      * Generate updates for the children of this window
      */
 
     for (childPtr = winPtr->childList; childPtr != NULL;
-	    childPtr = childPtr->nextPtr) {
-	if (!Tk_IsMapped(childPtr) || Tk_IsTopLevel(childPtr)) {
-	    continue;
-	}
-	GenerateUpdates(updateRgn, updateBounds, childPtr);
+    	    childPtr = childPtr->nextPtr) {
+    	if (!Tk_IsMapped(childPtr) || Tk_IsTopLevel(childPtr)) {
+    	    continue;
+    	}
+    	GenerateUpdates(updateRgn, updateBounds, childPtr);
     }
 
     /*
      * Generate updates for any contained windows
      */
 
     if (Tk_IsContainer(winPtr)) {
-	childPtr = TkpGetOtherWindow(winPtr);
-	if (childPtr != NULL && Tk_IsMapped(childPtr)) {
-	    GenerateUpdates(updateRgn, updateBounds, childPtr);
-	}
+        childPtr = TkpGetOtherWindow(winPtr);
+        if (childPtr != NULL && Tk_IsMapped(childPtr)) {
+            GenerateUpdates(updateRgn, updateBounds, childPtr);
+        }
 
 	/*
 	 * TODO: Here we should handle out of process embedding.
 	 */
     }