gmg user commands don't fail gracefully for non existant users

[ayleph]

Attempt to delete a non-existent user using bin/gmg deleteuser and you'll get a Traceback similar to below.

$ bin/gmg deleteuser idontexist
Traceback (most recent call last):
  File "bin/gmg", line 9, in <module>
    load_entry_point('mediagoblin==0.7.1.dev', 'console_scripts', 'gmg')()
  File "/path/to/mediagoblin/mediagoblin/gmg_commands/__init__.py", line 124, in main_cli
    args.func(args)
  File "/path/to/mediagoblin/mediagoblin/gmg_commands/users.py", line 132, in deleteuser
    username=unicode(args.username.lower())).one()
  File "build/bdist.linux-x86_64/egg/sqlalchemy/orm/query.py", line 2329, in one
sqlalchemy.orm.exc.NoResultFound: No row was found for one()

Same problem exists for other commands in users.py.

[ayleph]

Elrond suggested the following change, which tested out fine for existing and non-existing users on my system.

mediagoblin/gmg_commands/users.py:

@@ -129,7 +129,7 @@ def deleteuser(args):
     db = mg_globals.database
 
     user = db.User.query.filter_by(
-        username=unicode(args.username.lower())).one()
+        username=unicode(args.username.lower())).first()
     if user:
         user.delete()
         print 'The user %s has been deleted' % args.username

[ayleph]

Fix pushed to ​https://gitorious.org/mediagoblin/aylephs-mediagoblin/commit/f0e795df82596e476d9f116d58012e563bb064a4

[ayleph]

Pushed to master.

​https://gitorious.org/mediagoblin/mediagoblin/commit/f0e795df82596e476d9f116d58012e563bb064a4

[Elrond]

We just realized, that users.py is affected globally.

Notes:

1. Wait until py3 merge is over!
2. Instead of doing unicode(...) (or six.text_type) in the db query, try doing a type=six.text_type in the .add_argument of the parser setup, so that the parser already does the typing for us.