Regression: UnboundLocalError: cannot access local variable 'middle'

[justanotheranonymoususer]

Version: c87a78c

import markdown2

# This input raises an exception:
# UnboundLocalError: cannot access local variable 'middle' where it is not associated with a value
#
# Expected:
# Anything but an exception
#
# Actual:
# Exception raised
markdown_text = R"""
*[*test**](https://example.com/)
"""
print(markdown2.markdown(markdown_text))