Issue #19373: Patch to Tk 8.5.15 to correct refresh problem on OS x 10.9.
From upstream checkin https://core.tcl.tk/tk/info/5a5abf71f9

--- tk8.5.15/macosx/tkMacOSXDraw.c	2013-09-16 09:41:21.000000000 -0700
+++ Tk_Source_Code-5a5abf71f9fdb0da/macosx/tkMacOSXDraw.c	2013-10-27 13:27:00.000000000 -0700
@@ -1688,6 +1688,7 @@
 {
     if (dcPtr->context) {
 	CGContextSynchronize(dcPtr->context);
+	[[dcPtr->view window] setViewsNeedDisplay:YES];
 	[[dcPtr->view window] enableFlushWindow];
 	if (dcPtr->focusLocked) {
 	    [dcPtr->view unlockFocus];