[migration] Improve update of in-memory schema during 3.18 CWAttribute.defaultval change
We weren't updating the schema properly so a bunch of structures still
had the old rdef with 'String' as object. That caused failures to add
new attributes later in the migration as their default value would be a
Binary object but the schema would expect a String.
Closes #3683640
from logilab.common.shellutils import generate_password
from cubicweb.server.utils import crypt_password
for user in rql('CWUser U WHERE U cw_source S, S name "system", U upassword P, U login L').entities():
salt = user.upassword.getvalue()
if crypt_password('', salt) == salt:
passwd = generate_password()
print 'setting random password for user %s' % user.login
user.set_attributes(upassword=passwd)
commit()