[3.15] gh-70758: Fix creating a turtle screen after closing one (GH-30355) (GH-155449)

Creating a new turtle screen after the previous one was closed no longer
raises turtle.Terminator on the first turtle command.
(cherry picked from commit 1286d43)

Co-authored-by: williamnavaraj <williamnavaraj@gmail.com>
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Author: 3 people

Lib/turtle.py

@@ -953,6 +953,9 @@ def __init__(self, cv, mode=_CFG["mode"],
             rootwindow.wm_attributes(topmost=True)
             rootwindow.wm_attributes(topmost=False)
 
+        # A new screen means that turtle graphics is running again.
+        TurtleScreen._RUNNING = True
+
     def clear(self):
         """Delete all drawings and all turtles from the TurtleScreen.
 

Misc/NEWS.d/next/Library/2022-01-03-12-50-42.gh-issue-70758.2NjFW_.rst

@@ -0,0 +1,2 @@
+Creating a new :mod:`turtle` screen after the previous one was closed no
+longer raises ``turtle.Terminator`` on the first turtle command.