MultiDict does not handle None values

[Sympatron]

The following code will result in a TypeError:

invalid_values = MultiDict([('a', 'x'), ('b', ''), ('d', None)])
print(invalid_values.get('a', type=int))  # None
print(invalid_values.get('b', type=int))  # None
print(invalid_values.get('c', type=int))  # None
print(invalid_values.get('d', type=int))  # TypeError

I think the expected behavior would be to return None as all other error cases do.

This happens because the following code only checks for ValueError and not other errors like TypeError:

werkzeug/src/werkzeug/datastructures/structures.py

Lines 81 to 84 in d3dd65a

	try:
	rv = type(rv)
	except ValueError:
	rv = default

[davidism]

Handling TypeError along with ValueError there makes sense.