Just some sanity checks for bow charging

mods/ITEMS/mcl_throwing/arrow.lua

@@ -4,7 +4,7 @@ local mod_awards = minetest.get_modpath("awards") and minetest.get_modpath("mcl_
 minetest.register_craftitem("mcl_throwing:arrow", {
 	description = "Arrow",
 	_doc_items_longdesc = "Arrows are ammunition for bows and dispensers.",
-	_doc_items_usagehelp = "To use arrows as ammunition for a bow, just put them anywhere in your inventory, they will be used up automatically. To use arrows as ammunition for a dispenser, place them in the dispenser's inventory.",
+	_doc_items_usagehelp = "To use arrows as ammunition for a bow, just put them anywhere in your inventory, they will be used up automatically. To use arrows as ammunition for a dispenser, place them in the dispenser's inventory. Arrows fired from a dispenser always deal 3 damage.",
 	inventory_image = "mcl_throwing_arrow_inv.png",
 	groups = { ammo=1, ammo_bow=1 },
 	_on_dispense = function(itemstack, dispenserpos, droppos, dropnode, dropdir)

mods/ITEMS/mcl_throwing/bow.lua

@@ -6,13 +6,22 @@ local arrows = {
 
 local GRAVITY = 9.81
 local BOW_DURABILITY = 385
-local BOW_CHARGE_TIME_HALF = 500000
-local BOW_CHARGE_TIME_FULL = 1000000
+
+-- Charging time in microseconds
+local BOW_CHARGE_TIME_HALF = 500000 -- bow level 1
+local BOW_CHARGE_TIME_FULL = 1000000 -- bow level 2 (full charge)
 
 -- TODO: Use Minecraft speed (ca. 53 m/s)
 -- Currently nerfed because at full speed the arrow would easily get out of the range of the loaded map.
 local BOW_MAX_SPEED = 26
 
+--[[ Store the charging state of each player.
+keys: player name
+value:
+false or nil = not charging or player not existing
+number: currently charging, the number is the time from minetest.get_us_time
+             in which the charging has started
+]]
 local bow_load = {}
 
 mcl_throwing.shoot_arrow = function(arrow_item, pos, dir, yaw, shooter, power, damage)
@@ -129,8 +138,19 @@ controls.register_on_release(function(player, key, time)
 		local has_shot = false
 
 		local speed, damage
-		local charge = minetest.get_us_time() - bow_load[player:get_player_name()]
+		local p_load = bow_load[player:get_player_name()]
+		local charge
+		-- Type sanity check
+		if type(p_load) == "number" then
+			charge = minetest.get_us_time() - p_load
+		else
+			-- In case something goes wrong ...
+			-- Just assume minimum charge.
+			charge = 0
+			minetest.log("warning", "[mcl_throwing] Player "..player:get_player_name().." fires arrow with non-numeric bow_load!")
+		end
 		charge = math.max(math.min(charge, BOW_CHARGE_TIME_FULL), 0)
+
 		local charge_ratio = charge / BOW_CHARGE_TIME_FULL
 		charge_ratio = math.max(math.min(charge_ratio, 1), 0)
 
@@ -139,7 +159,6 @@ controls.register_on_release(function(player, key, time)
 		if charge >= BOW_CHARGE_TIME_FULL then
 			speed = BOW_MAX_SPEED
 			local r = math.random(1,5)
-			-- Damage and range have been nerfed because the arrow charges very quickly
 			if r == 1 then
 				-- 20% chance for critical hit
 				damage = 10
@@ -208,6 +227,10 @@ minetest.register_globalstep(function(dtime)
 	end
 end)
 
+minetest.register_on_leaveplayer(function(player)
+	bow_load[player:get_player_name()] = nil
+end)
+
 if minetest.get_modpath("mcl_core") and minetest.get_modpath("mcl_mobitems") then
 	minetest.register_craft({
 		output = 'mcl_throwing:bow',