Maybe if a variable is initialized both in if and else blocks, the resulting type should be the union of the types of the initializers (only when using --allow-redefinitions):

if foo():
    x = 0
    # Type of x is 'int' here
else:
    x = ''  # No error here
    # Type of x is 'str' here
reveal_type(x)  # Union[int, str]

Currently the second assignment generates an error, and the type of x is int everywhere.

This is a generalization of #6232 and related to #1174 (but not a direct follow-up issue).