[repo] fix extid2entity to ensure connection's has a cnxset
else we'll call source.doexec, which attempt to access to cnxset.cu, and crash
in some case (eg unittest_cwxmlparser in sobjects/test).
Also, manually switch to 'write' mode to ensure cnxset is not released until
commit/rollback when some entity is inserted.
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()