bpo-33203: Ensure random.choice always raises IndexError on empty sequence (GH-6338) (GH-6387)

(cherry picked from commit 091e95e900)

Co-authored-by: Wolfgang Maier <wolfgang.maier@biologie.uni-freiburg.de>

Lib/random.py

@@ -242,6 +242,8 @@ class Random(_random.Random):
                 "enough bits to choose from a population range this large.\n"
                 "To remove the range limitation, add a getrandbits() method.")
             return int(random() * n)
+        if n == 0:
+            raise ValueError("Boundary cannot be zero")
         rem = maxsize % n
         limit = (maxsize - rem) / maxsize   # int(limit * maxsize) % n == 0
         r = random()