SF 1676321: empty() returned wrong result

Lib/sched.py

@@ -72,7 +72,7 @@ class scheduler:
 
     def empty(self):
         """Check whether the queue is empty."""
-        return not not self.queue
+        return not self.queue
 
     def run(self):
         """Execute events until the queue is empty.

Misc/NEWS

@@ -197,6 +197,8 @@ Extension Modules
 Library
 -------
 
+- Bugs #1676321:  the empty() function in sched.py returned the wrong result
+
 - unittest now verifies more of its assumptions. In particular, TestCase
   and TestSuite subclasses (not instances) are no longer accepted in
   TestSuite.addTest(). This should cause no incompatibility since it