[FIX] mail: no crash when searching messages

Revision on https://github.com/odoo/odoo/commit/299ebb2cdf63de2e3967da0d2f3e7effd239812b

The commit above added the notion of moderation, which
requires re-rendering the thread when a message has its
moderation changed (i.e. the message is deleted on reject
or is no longer marked as 'pending moderation').

However, this condition was triggered even when the
moderation status on the message has not changed.

This introduced a crash when using the search in discuss:

- Access a channel with more than 30 messages, so that
  not all messages have been fetched.
- Search messages in this thread so that it displays more
  than 30 messages, and the last message of those has already
  been fetched.
> It crashes with "Cannot read property 'getID' of undefined".

The bug comes from re-fetching messages: it behaves as a
"load more" fetch, although no message has been stored yet.
A "load more" fetch requires at least one message in order to
determine the minimum message ID to fetch, thus the crash due
to having no message to get such an ID.

Here's the explanation why it fetches with load more:
when performing the search and fetching the same last message,
it will detect that it has already been fetched. Its moderation
status is 'accepted', and it will assume a change of moderation
status. This will trigger a fetch and render of the thread.
At this moment, if the search exceeds the fetch limit, not all
messages will be fetched, so that this fetch is considered as a
"load more" fetch.

This commit fixes the issue by only re-rendering the thread
when there is a change of the moderation status on an already
fetched message. Since changes of the moderation status are
handled by means of the longpolling, it should be rare to run
into the case of having a change of moderation status on a
message while using the search on a thread.

Task-ID 1910180

0 files changed, 0 insertions, 0 deletions