Instead of silently defaulting to SITEID when courseid (coming
from message_send()/\core\message\manager::send_message()) is missing,
now a debugging message is shown to allow developers to fix their
messages to, always, include courseid.
Raw creation of events via message_sent::create() missing other[courseid]
leads to coding exception since now (there shouldn't be any legacy use, as far as
they are always created via create_from_ids() when sending a message.
Updated upgrade.txt notes a little bit, added references the 3.6 final
deprecation issue (MDL-55449) and covered with unit tests.
This patch includes following fixes:
- messages may be now sent when database transactions active
- consistent return status on failure from message_send(), false is
returned only when message not created in message(_read)? table,
processor failure results in debugging message only and messages
are not marked as read
- message_sent is triggered always with id from message table
- logic for marking messages as viewed was standardised
- message_viewed event is triggered consistently
- improved performance when fetching user preferences
- full unit tests coverage for send_message() function
- fixed multiple other smaller issues discovered by unit tests
