Message list on "general chat" fails to get new messages

[gnprice]

The original reported symptom is: you open a notification that takes you to a conversation, then try sending messages there, and the messages don't appear. This only happens when the conversation is in the "general chat" topic (or more generally, the value of realmEmptyTopicDisplayName).

The same behavior can also happen without a notification, if you follow a link like #test here > general chat, as in #**test here>general chat**. (Things work fine if the link is instead #test here > general chat, as in #**test here>** — the form the Zulip clients prefer to generate.)

To fix, when opening a message list to a topic narrow, we should normalize the topic. We want the topic to be such that when a message is sent to it, it comes back on that same topic — so probably this means calling TopicName.processLikeServer.

(That also suggests that the same symptom would affect a link to "(no topic)" the same way as a link to "general chat". I haven't tested to confirm that.)

References

• User report, and debugging thread: #mobile > flutter app didn't show message after posting @ 💬