[Mailman-Developers] REST API delete user function does not delete every 2nd linked address

[Barry Warsaw]

On Feb 09, 2015, at 07:06 AM, Andrew Stuart wrote:

>This appears to fix the problme in rest/users.py
>
>    def on_delete(self, request, response):
>        """Delete the named user, all her memberships, and addresses."""
>        if self._user is None:
>            not_found(response)
>            return
>        for member in self._user.memberships.members:
>            member.unsubscribe()
>        user_manager = getUtility(IUserManager)
>        addresses_for_deletion = []
>        for address in self._user.addresses:
>            # to avoid mutating the self._user.addresses iterator, create a separate list of addresses
>            addresses_for_deletion.append(address)
>        for address in addresses_for_deletion:
>            user_manager.delete_address(address)
>        user_manager.delete_user(self._user)
>        no_content(response)

Thanks for tracking this down.  I don't know whether this may have changed
between Storm and SQLAlchemy, but it's very likely at least now caused by the
old mutate-dictionary-while-iterating problem.  With the switch to Python 3,
if it were a dictionary an exception would have been thrown:

Python 3.4.2 (default, Feb  3 2015, 14:26:38) 
[GCC 4.9.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> d = dict(a=1, b=2, c=3, d=4)
>>> for k in d:
...   del d[k]
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
RuntimeError: dictionary changed size during iteration
>>>

Thanks for opening the bug; I'll work up a test case and a fix, but I think
you're in the right direction.

Cheers,
-Barry