[Sqlalchemy-tickets] Issue #4240: Cannot copy new ForeignKeyConstraint (zzzeek/sqlalchemy)

[fantix N. <iss...@bi...>]

New issue 4240: Cannot copy new ForeignKeyConstraint
https://bitbucket.org/zzzeek/sqlalchemy/issues/4240/cannot-copy-new-foreignkeyconstraint

fantix NA:

* SQLAlchemy version: 1.2.6
 * Database: N/A

Scenario: Using a list of common columns/constraints to define different tables.

Code to reproduce:

    import sqlalchemy
    sqlalchemy.ForeignKeyConstraint(['user_id'], ['users.id']).copy()

Traceback:

    Traceback (most recent call last):
      File "test.py", line 2, in <module>
        sqlalchemy.ForeignKeyConstraint(['user_id'], ['users.id']).copy()
      File "sqlalchemy/sql/schema.py", line 3063, in copy
        [x.parent.key for x in self.elements],
      File "sqlalchemy/sql/schema.py", line 3063, in <listcomp>
        [x.parent.key for x in self.elements],
    AttributeError: 'NoneType' object has no attribute 'key'