hotfixes checks for player object on sudden disconnections

* is very know bug never resolved at https://github.com/minetest/minetest#8452
* In fact there's already some check for players around connected players but only for names
* this fixed and close https://notabug.org/TenPlus1/stamina/issues/8
* this fixed and close https://codeberg.org/minenux/minetest-mod-stamina/issues/8
* already fix backguard compat for eye_height close https://codeberg.org/minenux/minetest-mod-stamina/issues/9
* already fix backguard compat for eye_height closes https://notabug.org/TenPlus1/stamina/issues/9

init.lua

@@ -143,6 +143,7 @@ local function set_sprinting(name, sprinting)
 
 	local player = minetest.get_player_by_name(name)
 
+	if player then
 		-- get player physics
 		local def = player:get_physics_override()
 
@@ -203,12 +204,15 @@ local function set_sprinting(name, sprinting)
 			end
 		end
 	end
+end
 
 
 local function head_particle(player, texture)
 
+	if player then
 		local prop = player:get_properties()
-	local pos = player:get_pos() ; pos.y = pos.y + prop.eye_height -- mouth level
+		local eye_height = prop.eye_height or 1.23
+		local pos = player:get_pos() ; pos.y = pos.y + eye_height -- mouth level
 		local dir = player:get_look_dir()
 
 
@@ -228,11 +232,14 @@ local function head_particle(player, texture)
 			texture = texture
 		})
 	end
+end
 
 local function drunk_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
+		if player then
+
 			local name = player:get_player_name()
 
 			if name
@@ -272,6 +279,9 @@ local function drunk_tick()
 					player:set_look_horizontal(yaw)
 				end
 			end
+
+		end
+
 	end
 end
 
@@ -280,6 +290,8 @@ local function health_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
+		if player then
+
 			local air = player:get_breath() or 0
 			local hp = player:get_hp()
 			local h = get_int_attribute(player)
@@ -307,12 +319,15 @@ local function health_tick()
 			end
 		end
 	end
+end
 
 
 local function action_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
+		if player then
+
 			local controls = player and player:get_player_control()
 
 			-- Determine if the player is walking or jumping
@@ -391,13 +406,16 @@ local function action_tick()
 			-- END sprint
 		end
 	end
+end
 
 
 local function poison_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
-		local name = player and player:get_player_name()
+		if player then
+
+			local name = player:get_player_name()
 
 			if name
 			and stamina.players[name]
@@ -429,17 +447,23 @@ local function poison_tick()
 			end
 		end
 	end
+end
 
 
 local function stamina_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
+		if player then
+
 			local h = get_int_attribute(player)
 
 			if h and h > STAMINA_TICK_MIN then
 				stamina_update_level(player, h - 1)
 			end
+
+		end
+
 	end
 end
 
@@ -614,6 +638,7 @@ and minetest.settings:get_bool("enable_stamina") ~= false then
 
 		local level = STAMINA_VISUAL_MAX -- TODO
 
+		if player then
 			if get_int_attribute(player) then
 
 				level = math.min(get_int_attribute(player), STAMINA_VISUAL_MAX)
@@ -644,10 +669,12 @@ and minetest.settings:get_bool("enable_stamina") ~= false then
 				drunk = nil,
 				sprint = nil
 			}
+		end
 	end)
 
 	minetest.register_on_respawnplayer(function(player)
 
+		if player then
 			local name = player:get_player_name()
 
 			if stamina.players[name].poisoned
@@ -661,6 +688,7 @@ and minetest.settings:get_bool("enable_stamina") ~= false then
 			stamina.players[name].sprint = nil
 
 			stamina_update_level(player, STAMINA_VISUAL_MAX)
+		end
 	end)
 
 	minetest.register_globalstep(stamina_globaltimer)
@@ -686,14 +714,18 @@ else
 
 	-- create player table on join
 	minetest.register_on_joinplayer(function(player)
+		if player then
 			stamina.players[player:get_player_name()] = {
 				poisoned = nil, sprint = nil, drunk = nil, exhaustion = 0}
+		end
 	end)
 end
 
 -- clear when player leaves
 minetest.register_on_leaveplayer(function(player)
+	if player then
 		stamina.players[player:get_player_name()] = nil
+	end
 end)
 
 
@@ -705,6 +737,7 @@ and minetest.settings:get_bool("enable_stamina") ~= false then
 	local effect_me = function(pos, player, def)
 
 		local green = minetest.get_color_escape_sequence("#bada55")
+		if player then
 			local name = player:get_player_name()
 
 			if def.poison or def.drunk then
@@ -729,6 +762,8 @@ and minetest.settings:get_bool("enable_stamina") ~= false then
 			end
 		end
 
+	end
+
 	lucky_block:add_blocks({
 		{"cus", effect_me, {poison = 5} },
 		{"cus", effect_me, {poison = 10} },