Close issue #8931: Make alternate formatting for 'c' raise an exception. Patch by Torsten Landschoff.
diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py
index ec10752..11d9546 100644
--- a/Lib/test/test_types.py
+++ b/Lib/test/test_types.py
@@ -343,6 +343,8 @@
self.assertRaises(ValueError, 3 .__format__, ",n")
# can't have ',' with 'c'
self.assertRaises(ValueError, 3 .__format__, ",c")
+ # can't have '#' with 'c'
+ self.assertRaises(ValueError, 3 .__format__, "#c")
# ensure that only int and float type specifiers work
for format_spec in ([chr(x) for x in range(ord('a'), ord('z')+1)] +