upstream merge sync: fix redundant checks for players, backguard compatibility

* sync commit "added 0.4.x support and fake player check function"

init.lua

@@ -24,7 +24,6 @@ STAMINA_STARVE_LVL = 3		-- level of staturation that causes starving
 
 STAMINA_VISUAL_MAX = 20		-- hud bar extends only to 20
 
-local is_50 = minetest.has_feature("object_use_texture_alpha")
 
 local function clamp(val, minval, maxval)
 	return math.max(math.min(val, maxval), minval)
@@ -37,37 +36,50 @@ SPRINT_JUMP  = clamp(tonumber(minetest.settings:get("stamina_sprint_jump")) or 0
 -- how fast to drain satation while sprinting (0-1)
 SPRINT_DRAIN  = clamp(tonumber(minetest.settings:get("stamina_sprint_drain")) or 0.35, 0.0, 1.0)
 
+-- minetest 5.x check
+local is_50 = minetest.has_feature("object_use_texture_alpha")
+
+-- are we a real player ?
+local function is_player(player)
 
-local function ck_player(player)
 	-- pipeworks fake player check its not necesary with real player check:
 	if player then if minetest.is_player(player) then return true end end
-	return false
+
 end
 
 local function get_int_attribute(player)
 
-	if not ck_player(player) then return nil end
+	if not is_player(player) then
+		return nil
+	end
 
 	local level
+
 	if is_50 then
+
 		local meta = player:get_meta()
 		level = meta and meta:get_string("stamina:level")
 	else
 		level = player and player:get_attribute("stamina:level")
 	end
 
-	if level then return tonumber(level) end -- true its converted to number, even false
+	if level then
+		return tonumber(level)
+	end
 
 	return nil
 end
 
+
 local stamina_enabled = minetest.settings:get_bool("enable_stamina") ~= false
 local damage_enabled = minetest.settings:get_bool("enable_damage")
 
 
 local function stamina_update_level(player, level)
 
-	if not ck_player(player) then return nil end
+	if not is_player(player) then
+		return nil
+	end
 
 	local old = get_int_attribute(player)
 
@@ -81,7 +93,9 @@ local function stamina_update_level(player, level)
 	end
 
 	if is_50 then
+
 		local meta = player and player:get_meta() ; if not meta then return end
+
 		meta:set_string("stamina:level", level)
 	else
 		player:set_attribute("stamina:level", level)
@@ -118,9 +132,7 @@ end
 
 local function exhaust_player(player, v)
 
-	if not player
-	or not ck_player(player) -- player.is_player can return nill in rare cases, and real check of player here
-	or not player.set_attribute then
+	if not is_player(player) then
 		return
 	end
 
@@ -222,7 +234,7 @@ end
 
 local function head_particle(player, texture)
 
-	if not ck_player(player) then return end
+	if not player then return end
 
 	local prop = player:get_properties()
 	local pos = player:get_pos() ; pos.y = pos.y + (prop.eye_height or 1.23) -- mouth level
@@ -250,7 +262,7 @@ local function drunk_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
-		if not ck_player(player) then return end -- need cos some rare cases during game running object is not player
+		if not is_player(player) then return end -- need cos some rare cases during game running object is not player
 
 		local name = player:get_player_name()
 
@@ -299,7 +311,7 @@ local function health_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
-		if not ck_player(player) then return end -- need cos some rare cases during game running object is not player
+		if not is_player(player) then return end -- need cos some rare cases during game running object is not player
 
 		local name = player:get_player_name()
 
@@ -335,7 +347,7 @@ local function action_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
-		if not ck_player(player) then return end -- need cos some rare cases during game running object is not player
+		if not is_player(player) then return end -- need cos some rare cases during game running object is not player
 
 		local controls = player:get_player_control()
 
@@ -356,7 +368,7 @@ local function action_tick()
 		--- START sprint
 		if enable_sprint then
 
-			local name = player and player:get_player_name()
+			local name = player:get_player_name()
 
 			-- check if player can sprint (stamina must be over 6 points)
 			if name
@@ -421,7 +433,7 @@ local function poison_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
-		if not ck_player(player) then return end -- need cos some rare cases during game running object is not player
+		if not is_player(player) then return end -- need cos some rare cases during game running object is not player
 
 		local name = player:get_player_name()
 
@@ -461,7 +473,7 @@ local function stamina_tick()
 
 	for _,player in ipairs(minetest.get_connected_players()) do
 
-		if not ck_player(player) then return end -- need cos some rare cases during game running object is not player
+		if not is_player(player) then return end -- need cos some rare cases during game running object is not player
 
 		local h = get_int_attribute(player)
 
@@ -516,7 +528,7 @@ if damage_enabled and minetest.settings:get_bool("enable_stamina") ~= false then
 	-- override core.do_item_eat() so we can redirect hp_change to stamina
 	core.do_item_eat = function(hp_change, replace_with_item, itemstack, user, pointed_thing)
 
-		if not ck_player(user) then return end -- abort if called by fake player (eg. pipeworks-wielder)
+		if not is_player(user) then return end -- abort if called by fake player (eg. pipeworks-wielder)
 
 		local old_itemstack = itemstack
 
@@ -641,13 +653,12 @@ if damage_enabled and minetest.settings:get_bool("enable_stamina") ~= false then
 
 		local level = STAMINA_VISUAL_MAX -- TODO
 
-		-- the code here was redundant cos get_int_attribute already call the level
-		-- but with backguard compat, tenplus1 just inherint the code but with removed backguard compatibility
-		-- also here we do not check if name its valid, object its already valid
 		if get_int_attribute(player) then
 			level = math.min(get_int_attribute(player), STAMINA_VISUAL_MAX)
 		end
+
 		if is_50 then
+
 			local meta = player:get_meta()
 			if meta then meta:set_string("stamina:level", level) end
 		else