Handle mailboxes with spaces

The IMAP4 protocol optionally uses double quoting when mailboxes contain
spaces. This is always allowed. So to fix this, first we use shlex to
perform double-quote-aware splitting (a bit like bash would split
command line arguments) and then we send folder names with quotes to the
IMAP server.

I tested this manually with a couple real IMAP servers.

mail_check_mailbox_size/models/fetchmail.py

@@ -1,4 +1,5 @@
 import logging
+import shlex
 from odoo import models, fields, api, _
 
 _logger = logging.getLogger(__name__)
@@ -53,12 +54,11 @@ class Fetchmail(models.Model):
                 number_of_messages_all = 0
                 size_all = 0
                 for item in list:
-                    x = item.decode().split()
+                    x = shlex.split(item.decode())
                     mailbox = x[-1]
-
                     # Select the desired folder
                     result, number_of_messages = imap_server.select(
-                        mailbox, readonly=1)
+                        '"{}"'.format(mailbox), readonly=1)
                     if result != 'OK':
                         _logger.info(
                             "Server %s responded %s for folder %s"