Make TimeoutQueue.iter() actually expire items

It is functionally fine not to, but causes objects to never be freed
if iter() is the only method called on the queue (ie. no
enqueue/dequeue, len(), ...)

src/utils/structures.py

@@ -1,6 +1,6 @@
 ###
 # Copyright (c) 2002-2009, Jeremiah Fincher
-# Copyright (c) 2010-2021, Valentin Lorentz
+# Copyright (c) 2010-2022, Valentin Lorentz
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -349,7 +349,10 @@ class TimeoutQueue(object):
         return self.queue.dequeue()[1]
 
     def __iter__(self):
-        # We could _clearOldElements here, but what happens if someone stores
+        self._clearOldElements()
+
+        # You may think re-checking _getTimeout() after we just called
+        # _clearOldElements is redundant, but what happens if someone stores
         # the resulting generator and elements that should've timed out are
         # yielded?  Hmm?  What happens then, smarty-pants?
         for (t, elt) in self.queue:

test/test_utils.py

@@ -1,7 +1,7 @@
 ###
 # Copyright (c) 2002-2005, Jeremiah Fincher
 # Copyright (c) 2009,2011, James McCoy
-# Copyright (c) 2010-2021, Valentin Lorentz
+# Copyright (c) 2010-2022, Valentin Lorentz
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -1182,6 +1182,31 @@ class TestTimeoutQueue(SupyTestCase):
         q.reset()
         self.assertFalse(1 in q)
 
+    def testClean(self):
+        def iter_and_next(q):
+            next(iter(q))
+
+        def contains(q):
+            42 in q
+
+        for f in (len, repr, list, iter_and_next, contains):
+            print(f)
+            with self.subTest(f=f.__name__):
+                q = TimeoutQueue(1)
+                q.enqueue(1)
+                timeFastForward(0.5)
+                q.enqueue(2)
+
+                self.assertEqual([x for (_, x) in q.queue], [1, 2])
+                f(q)
+                self.assertEqual([x for (_, x) in q.queue], [1, 2])
+
+                timeFastForward(0.6)
+
+                self.assertEqual([x for (_, x) in q.queue], [1, 2])  # not cleaned yet
+                f(q)
+                self.assertEqual([x for (_, x) in q.queue], [2])  # now it is
+
 class TestCacheDict(SupyTestCase):
     def testMaxNeverExceeded(self):
         max = 10