Steps to reproduce

1. In persistentconversationbot.py, change persistent=True to persistent=False

2. Start the bot, give the bot some information to store

3. Stop bot

4. Start bot again, send command /show_data. It will be empty

Expected behaviour

user_data changed within a conversation should be persisted even if the conversation is not
(i.e., I would expect this)

Actual behaviour

user_data changed within a conversation that is not persisted, will not be persisted

Configuration

Raspbian GNU/Linux 9 (stretch)

Version of Python, python-telegram-bot & dependencies:

python-telegram-bot 11.1.0
certifi 2018.01.18
future 0.17.1
Python 3.5.3 (default, Sep 27 2018, 17:25:39)  [GCC 6.3.0 20170516]

Research so far:

1. When the conversation is persisted, the user_data will only be persisted, if single_file = True. This is because this will trigger dump_singlefile() in picklepersistence.py on update in Conversation. When setting single_file = False, user_data will not be persisted

2. Things go south in update_user_data(). Printing the result of

   self.user_data.get(user_id) == data:
   

   always gives True even though self.user_data.[user_id] has changed after user input (as one can test by printing it).

I therefore conclude, that self.user_data[user_id] must be changed somewhere along the way before update_user_data() is called. Still, I can't pinpoint, where that happens. Will try and find it.

If you have a clue, please let me know :)