A follow up for issue #15906: change the test for calling the type conversion
on the action's default, reverting it back to previous behavior. Conversion
is only done on string defaults.
Add a test for this and another test that ensures such type conversions are
only called once.
diff --git a/Lib/argparse.py b/Lib/argparse.py
index 440d8fa..30bae57 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -1948,7 +1948,7 @@
# twice (which may fail) if the argument was given, but
# only if it was defined already in the namespace
if (action.default is not None and
- isinstance(action, _StoreAction) and
+ isinstance(action.default, basestring) and
hasattr(namespace, action.dest) and
action.default is getattr(namespace, action.dest)):
setattr(namespace, action.dest,