Fix hitech weapons

[robertxgray]

Hitech weapons use the obsolete get_metadata and set_metadata functions to get and update the technic charge. They have been replaced by get_meta:get_int and get_meta:set_int.

[wsor4035]

key changes from charge to technic:charge is this something both technics have changed?

[robertxgray]

I found a bug after further testing. Here is another version.

[S-S-X]

Didn't forget this one but it might have something to do with linked Technic Plus 1.2.x PR. That would be backporting technic.use_RE_charge(itemstack, charge) from Technic Plus Beta and in turn allow using single path for all latest Technic Plus releases.

Give it a few days and we'll see if we'd get somewhere with that.
After all didn't really do it just for this PR but moreover it would be good to do the same for many high-compatibility features, especially those that have been added to original Technic and Technic Plus Beta but not for Technic Plus stable CDB release.

[S-S-X]

I think this would be enough for both migration and usage with original Technic, Technic Plus stable and Technic Plus Beta if we get mt-mods/technic#391 through:

Suggested change

	-- Technic Plus
	local meta = itemstack:get_meta()
	local old_metadata = minetest.deserialize(meta:get_string(""))
	local charge = nil
	if old_metadata then
	charge = old_metadata.charge
	end
	-- Technic
	if not charge then
	charge = meta:get_int("technic:charge")
	end
	if charge < technic_charge_per_use then
	reload = true
	else
	if not technic.creative_mode then
	charge = charge - technic_charge_per_use
	technic.set_RE_wear(itemstack, charge, technic_charge)
	if old_metadata and old_metadata.charge then
	old_metadata.charge = charge
	meta:set_string("", minetest.serialize(old_metadata))
	else
	meta:set_int("technic:charge", charge)
	end
	end
	end
	-- Technic, old metadata migration
	local meta = itemstack:get_meta()
	local old_metadata = core.deserialize(meta:get_string(""))
	if old_metadata and old_metadata.charge then
	technic.set_charge(itemstack, old_metadata.charge)
	meta:set_string("", "")
	end
	-- Technic, check and use charge
	local charge = technic.get_charge(itemstack)
	if charge < technic_charge_per_use then
	reload = true
	elseif not technic.creative_mode then
	technic.set_charge(itemstack, charge - technic_charge_per_use)
	end

That's already +15 -26 LoC

Considering simplicity of changes and compatibility gains on Technic Plus side for me this seems significant improvement.

[S-S-X]

Also any Technic fork that implement technic.get_charge and technic.set_charge no matter how charge is actually stored.

Though if any of the forks with these are still using old meta then migration would do unnecessary metadata reset each time.

Also I'm not sure if full old metadata reset is safe with these items, if something else round here uses old metadata then that something else would be lost too. However I'd argue full cleanup of old metadata would be very good in case it isn't needed.