In Minetest 5.4.1, calling get_player_control() on a mob returned the
empty string. Minetest commit 5eb45e1ea03c6104f007efec6dd9c351f310193d
changed this, so now calling get_player_control() on a mob returns nil.
As mcl_boats defines boats that can have a player or a mob as a driver,
code like the following crashes with a changed get_player_control() API:
local ctrl = driver:get_player_control()
if ctrl.sneak then
detach_object(driver, true)
end
Furthermore, once a world has crashed, joining it near a mob that is the
driver of a boat with such control code immediately crashes again.
When I reported this bug to Minetest, several Minetest core developers
stated that they disliked the old API and proposed other return values
for calling a mob's get_player_control() function – all different from
the empty string. Since I have some doubts that this bug will be fixed
in Minetest 5.5.0, boat code must take into account a nil return value.
Minetest issue: https://github.com/minetest/minetest/issues/11989
Before this patch, the light level that makes mobs that burn in sunlight
catch fire had been mistakenly specified as minetest.LIGHT_MAX or more.
The correct light level for sunlight is LIGHT_SUN, which is one higher
than minetest.LIGHT_MAX. Since minetest.LIGHT_MAX is the maximum light
value that a node can have and torches emit light at that light level,
mobs that burn in sunlight caught fire inside torch nodes.
The “getwrittenbook” command gives a player that has the “debug” privilege a book
with a configurable amount of characters. This was added as a debug aid, to help
reproducing situations in which items with lots of metadata trigger issues like
heavy lag or server crashes.
Some items, like shulkers or books, can have so much metadata that the
corresponding item entity can not be serialized by the Minetest engine.
Without this patch, dropping such an item and then moving away crashes
Minetest, as it can not serialize the entity with serializeString16()
when unloading a map block.
The patch resets the overlong metadata of non-serializable item entities.
This avoids a crash and makes it possible to retrieve a “sanitized” item
without metadata when the mapblock containing the item entity is reloaded.
Originally sfan5 guessed the maximum possible item entity serialization size
that would not lead to a crash as 65530 bytes, but anon5 calculated it to be
actually 65487 bytes. This has been experimentally verified by erlehmann.
Group levels are now specified as a list of names when registering a
digging group. Digging groups which do not have specified levels will
support tools having two levels, 0 and 1 where 0 means the tool can dig
but not harvest the node and 1 means it can also harvest the node. If
more levels are required one has to specifiy them when registering the
digging group.
These changes are primarly made to make mcl_autogroup more efficient.
Previously enchanted tools required storing around 21 kB of metadata due
to the way the previous version of the mod was implemented. This caused
a lot of lag and a huge amount of network traffic. With the changes
enchanted tools won't require more than 1 kB of metadata.
The mod is also rewritten to use an API to register digging groups and
compute the groupcaps for tools. This will make it easier for modders
to register custom digging groups.
The mod is now split up into two parts. One part called "mcl_autogroup"
to implement the API for registering custom digging groups, and the
other part called "_mcl_autogroup" which contains most of the code which
has to be loaded after most mods.
