Reproducer:
* Have some unreads in the Combined feed view.
* Scroll up and select a message that was not part of initial fetch.
* Reload.
* Go a another narrow.
* Come back to combined feed to find your at a random message. This
message is actually last message of the current fetch of
combined feed view which was returned via `first_unread_message_id`.
Important changes in this commit:
* We only cache message list for "Combined feed" if it is the
default view.
* We modify existing handling of home message list code so that
it can be used to for any message list that we want to cache
using a new `preserve_rendered_state` variable.
* narrow_state.filter() returns the filter of combined feed view list
instead of `undefined`.
* We start fetching messages from the latest message on app load.
* Messages in all messages data and Recent view are always synced.
* If combined feed view list is not cached, we don't track it's
last pointer, effectively sending user to the latest unread
message always .
For spectators, the chunk of page_params that originates from
do_events_register isn’t assigned until ui_init.js. That means the
TypeScript type of page_params is mostly a lie during module load
time: reading a parameter too early silently results in undefined
rather than the declared type, with unpredictable results later on.
We want to make such an early read into an immediate runtime error,
for both users and spectators consistently, and pave the way for
runtime validation of the page_params type. As a first step, split
out the subset of fields that pertain to the current user.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Aman Agrawal
Anders Kaseorg
evykassirer