Tested with nodebreaker, fire.

If called from lua, minetest.remove_node() calls on_destruct() callbacks
before the map is actually updated. This means that we can't look at the
map data to determine if we're done cleaning up adjacent nodes, and we
have to stop recursing some other way.

There's no data we can pass around through functions that would survive
scope to a secondary on_destruct() callback, so we have to maintain
local state somewhere in the mod namespace.

In this case, we keep a bitflag. The bitflag is set to "true" by
default. On the first half removal, the flag is flipped and afterwards
we remove the other half node. When the on_destruct for the other half
is running, it's value is false and we flip it back to true without
removing the other half node.

This thus prevents recursing.

To facilitate easier finding of the bed partner, we tell our on_destruct
whether we're a top or bottom half node through a passed flag.

Now that the top is diggable, we just need to assure that it drops a
bottom bed part.

I've found a favorable steel door sound from a parking garage
door that isn't abrupt or scary, just sounds like a nice solid
metal door. The sample had both opening and closing sounds, and
so they match nicely. Amplified and mixed several samples together
to reduce ambient noise, and get the right level compared to
wood doors. Attribution was added as well. CC-BY-3.0 sounds.

Hue and saturation match desert stone and desert stone brick
Preserve original mortar colour

We raise the height of the fencegate node by 0.0001 to make the
fencegate post stop fighting with node blocks. This makes the
gate pole appear to be cut through the node, and doesn't leave
a gap when stacking fencegates, which would look odd.

No need to find_node_near twice with the same params.

Fixes #909. Door tops are never flammable.

This doesn't guard yet against a voxelmanip removing the top node,
but that is less of an issue since if a voxelmanip removes the top,
then the bottom part remains functional and visibly intact. If the
voxelmanip removes the bottom part, but not the top, then this patch
makes it clean up the top just fine.

This fixes a bug what crashes game when rotating an unknown node.

Correct 2 inconsistent mixes
Clean up code style and vertically align mix table
Remove dyelocal and simplify table names

The access privilege allows players that have it to bypass protection
on locked doors/trapdoors, chests and bones.

The priv also allows bypassing any minetest.is_protected() check,
including digging nodes and placing them. It is meant for world
moderators to clean up and fix map issues.

Original patch by red-001. Split up and rebased/rewritten by sofar.

This patch requires https://github.com/minetest/minetest/pull/3800

These basic connected wall nodes automatically connect
to neigboring stone blocks, other wall blocks and anything
that's "cracky". The do not connect to wood (fences will do
that).

The walls are generated using a new walls.register() API.
Documentation on the API is included in game_api.txt.

This change requires minetest/minetest#3503.

Walls are added for all cobble stone materials. They generally
look best and are the natural use cases for these materials.

This fence gate builds on NDT_CONNECTED by assuming fence nodes will
automatically connect to it's sides properly. The fence gate will
open and close just like doors, with sounds, but it only opens one
way. The gate sticks out quite a bit and can be bumped into, so the
fence may be used as some sort of path switch.

The fence gate offers no form of protection and can be opened and
closed by anyone. This is done on purpose - the fencegate isn't
meant to provide protection from players, as fences can be
trivially jumped over. Instead, these fences should be used for
protecting crops from hungry sheep, or keeping rabbits in their
pen, or just decoration. Mods can also modify the mod to add
protection, of course.

A recipe is added to make these. It's 4 sticks and 2 wood (any)
as follows:

  stick  wood  stick
  stick  wood  stick

The collision box of the open gate is such that if two gates are
connected but mirrored (making an M shape) then you can walk a large
entity that's larger than 1.0 wide through the opening. The gate of
an opened fence can also be stood upon or bumped into.

I've mixed together some sounds to provide a somewhat light sound
experience, one that one would expect from a small gate latching open
and close.

This change requires #873, otherwise it doesn't connect to fences.

This changes the drawtype of fences to NDT_CONNECTED nodebox drawtype.

These nodes are drawn by the client with the needed connections on
the fly as the scene is drawn. There is no logic needed by mods to
modify the nodes.

These fences connect to (1) other fences, (2) planks and (3) tree
trunks, but nothing else. They do not connect to stone, dirt, wool,
etc. This is done by the "connects_to" parameter, which takes groups
and node names.

Due to the way textures are wrapped, we can make these nodes look a
lot better by giving them a special tile.

This change requires minetest/minetest#3503.

Books still don't wrap long lines of text properly so until this has been sorted out I suggest reverting back to a previous working formspec which lets players read books properly until a fix is found (and maybe scrollbars added to texarea's).  Also adding a recipe to blank written books.

https://forum.minetest.net/viewtopic.php?f=42&t=1523&start=500#p208773

Currently, doors can be placed inside others' protected areas. We
need to check protection for both bottom and top halves.

Add function to detect nearby snow to enable snow on sapling-grown pine trees
Correct 'place schematic' rotation parameters to "0" or "random"

In mgv5/v7/flat/fractal/valleys
Add missing noise parameters to pine logs for
density to vary in relation to pine tree density

As requested by @paramat.
Leaves are preserved by default and only decay when using place + sneak.

Digging a cactus leaves the branches hanging. With this change it will no longer happen.

This is an adapted version of #861 - by oleastre

Most mods had been calling `doors.register_door() with a door
name that included the "modname:" prefix, and we should continue
to allow mods to do so, without registering the nodenames created
in the "doors:" namespace.

The default case is to use the "modname:" prefix verbatim. If
mods or code calls this function without a prefix, then "doors:"
is automatically used.

Now that the namespace is corrected, the copy replacement ABM is
no longer needed.

This function maps doors.register_door to the new API as far as
reasonable. We can't map the texture, so we fall back to a default
texture. An error message is printed if mod writers did not provide the
needed new tiles field for the door. The created doors are functional
and a full replacement. Old doors are replaced with the new ones
through an ABM.

A previous fix overwrote the `def` variable during registration,
causing protected doors no longer to be placed with protection.

These sounds were perceived to be too loud in the
game. I've lowered them significantly but they remain
plenty audible. The dig sounds were very loud as well
so I toned them down as well.