From 14678af2ed71c844f60eb8aba179a32992aba50e Mon Sep 17 00:00:00 2001
From: Wuzzy <almikes@aol.com>
Date: Thu, 17 Aug 2017 18:14:49 +0200
Subject: [PATCH] Portals: Fix rapid back-and-forth teleportation

---
 mods/ITEMS/mcl_portals/portal_end.lua    | 22 ++++++++++++++++++++--
 mods/ITEMS/mcl_portals/portal_nether.lua | 20 +++++++++++++++++++-
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/mods/ITEMS/mcl_portals/portal_end.lua b/mods/ITEMS/mcl_portals/portal_end.lua
index 44f0e1436d..d21c3ac9be 100644
--- a/mods/ITEMS/mcl_portals/portal_end.lua
+++ b/mods/ITEMS/mcl_portals/portal_end.lua
@@ -12,10 +12,14 @@ local np_cave = {
 	octaves = 5,
 	persist = 0.7
 }
-
 -- Portal frame material
 local portal_frame = "mcl_nether:quartz_block"
 
+-- Table of objects (including players) which recently teleported by a
+-- End portal. Those objects have a brief cooloff period before they
+-- can teleport again. This prevents annoying back-and-forth teleportation.
+local portal_cooloff = {}
+
 -- Destroy portal if pos (portal frame or portal node) got destroyed
 local destroy_portal = function(pos)
 	-- Deactivate Nether portal
@@ -326,6 +330,10 @@ minetest.register_abm({
 		for _,obj in ipairs(minetest.get_objects_inside_radius(pos,1)) do --maikerumine added for objects to travel
 		local lua_entity = obj:get_luaentity() --maikerumine added for objects to travel
 			if obj:is_player() or lua_entity then
+				-- No rapid back-and-forth teleportatio
+				if portal_cooloff[obj] then
+					return
+				end
 				local meta = minetest.get_meta(pos)
 				local target3 = minetest.string_to_pos(meta:get_string("portal_target"))
 				if target3 then
@@ -336,8 +344,12 @@ minetest.register_abm({
 							vector.subtract(target3, 4), vector.add(target3, 4))
 					end
 
-					-- teleport the player
+					-- teleport the object
 					minetest.after(3, function(obj, pos, target3)
+						-- No rapid back-and-forth teleportatio
+						if portal_cooloff[obj] then
+							return
+						end
 						local objpos = obj:getpos()
 						if objpos == nil then
 							return
@@ -366,6 +378,12 @@ minetest.register_abm({
 						obj:setpos(target3)
 						minetest.sound_play("mcl_portals_teleport", {pos=target3, gain=0.5, max_hear_distance = 16})
 
+						-- Enable teleportation cooloff to prevent frequent back-and-forth teleportation
+						portal_cooloff[obj] = true
+						minetest.after(3, function(o)
+							portal_cooloff[o] = false
+						end, obj)
+
 					end, obj, pos, target3)
 				end
 			end
diff --git a/mods/ITEMS/mcl_portals/portal_nether.lua b/mods/ITEMS/mcl_portals/portal_nether.lua
index 221af24aca..02430b2312 100644
--- a/mods/ITEMS/mcl_portals/portal_nether.lua
+++ b/mods/ITEMS/mcl_portals/portal_nether.lua
@@ -19,6 +19,11 @@ local np_cave = {
 	persist = 0.7
 }
 
+-- Table of objects (including players) which recently teleported by a
+-- Nether portal. Those objects have a brief cooloff period before they
+-- can teleport again. This prevents annoying back-and-forth teleportation.
+local portal_cooloff = {}
+
 -- Destroy portal if pos (portal frame or portal node) got destroyed
 local destroy_portal = function(pos)
 	-- Deactivate Nether portal
@@ -357,6 +362,10 @@ minetest.register_abm({
 		for _,obj in ipairs(minetest.get_objects_inside_radius(pos,1)) do		--maikerumine added for objects to travel
 			local lua_entity = obj:get_luaentity() --maikerumine added for objects to travel
 			if obj:is_player() or lua_entity then
+				-- Prevent quick back-and-forth teleportation
+				if portal_cooloff[obj] then
+					return
+				end
 				local meta = minetest.get_meta(pos)
 				local target = minetest.string_to_pos(meta:get_string("portal_target"))
 				if target then
@@ -366,8 +375,12 @@ minetest.register_abm({
 						minetest.emerge_area(
 							vector.subtract(target, 4), vector.add(target, 4))
 					end
-					-- teleport the player
+					-- teleport the object
 					minetest.after(3, function(obj, pos, target)
+						-- Prevent quick back-and-forth teleportation
+						if portal_cooloff[obj] then
+							return
+						end
 						local objpos = obj:getpos()
 						if objpos == nil then
 							return
@@ -397,6 +410,11 @@ minetest.register_abm({
 						obj:setpos(target)
 						minetest.sound_play("mcl_portals_teleport", {pos=target, gain=0.5, max_hear_distance = 16})
 
+						-- Enable teleportation cooloff for 4 seconds, to prevent back-and-forth teleportation
+						portal_cooloff[obj] = true
+						minetest.after(4, function(o)
+							portal_cooloff[o] = false
+						end, obj)
 
 					end, obj, pos, target)
 				end