gh-91212: Fixed flickering when the tracer is turned off (#95129)

Fixed flickering when the tracer is turned off.

Author: relent95

Lib/turtle.py

@@ -596,7 +596,6 @@ def _write(self, pos, txt, align, font, pencolor):
         item = self.cv.create_text(x-1, -y, text = txt, anchor = anchor[align],
                                         fill = pencolor, font = font)
         x0, y0, x1, y1 = self.cv.bbox(item)
-        self.cv.update()
         return item, x1-1
 
 ##    def _dot(self, pos, size, color):
@@ -3419,6 +3418,7 @@ def _write(self, txt, align, font):
         """
         item, end = self.screen._write(self._position, txt, align, font,
                                                           self._pencolor)
+        self._update()
         self.items.append(item)
         if self.undobuffer:
             self.undobuffer.push(("wri", item))

Lib/turtledemo/clock.py

@@ -109,7 +109,6 @@ def tick():
         writer.write(datum(t),
                      align="center", font=("Courier", 14, "bold"))
         writer.forward(85)
-        tracer(True)
         second_hand.setheading(6*sekunde)  # or here
         minute_hand.setheading(6*minute)
         hour_hand.setheading(30*stunde)

Misc/NEWS.d/next/Library/2022-07-22-09-09-08.gh-issue-91212.53O8Ab.rst

@@ -0,0 +1 @@
+Fixed flickering of the turtle window when the tracer is turned off. Patch by Shin-myoung-serp.