Server: announce MIN/MAX protocol version supported to serverlist. Client: check serverlist

Client now informs about incompatible servers from the list, this permits to prevent the protocol movements.
Server announces its supported protocol versions to master server

builtin/common/misc_helpers.lua

@@ -564,7 +564,7 @@ if INIT == "mainmenu" then
 		return nil
 	end
 
-	function fgettext(text, ...)
+	function fgettext_ne(text, ...)
 		text = core.gettext(text)
 		local arg = {n=select('#', ...), ...}
 		if arg.n >= 1 then
@@ -586,7 +586,11 @@ if INIT == "mainmenu" then
 			end
 			text = result
 		end
-		return core.formspec_escape(text)
+		return text
+	end
+
+	function fgettext(text, ...)
+		return core.formspec_escape(fgettext_ne(text, ...))
 	end
 end
 

builtin/mainmenu/common.lua

@@ -16,9 +16,15 @@
 --51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 --------------------------------------------------------------------------------
 -- Global menu data
----------------------------------------------------------------------------------
+--------------------------------------------------------------------------------
 menudata = {}
 
+--------------------------------------------------------------------------------
+-- Local cached values
+--------------------------------------------------------------------------------
+local min_supp_proto = core.get_min_supp_proto()
+local max_supp_proto = core.get_max_supp_proto()
+
 --------------------------------------------------------------------------------
 -- Menu helper functions
 --------------------------------------------------------------------------------
@@ -42,6 +48,25 @@ function image_column(tooltip, flagname)
 		"1=" .. core.formspec_escape(defaulttexturedir .. "server_flags_" .. flagname .. ".png")
 end
 
+--------------------------------------------------------------------------------
+function order_favorite_list(list)
+	local res = {}
+	--orders the favorite list after support
+	for i=1,#list,1 do
+		local fav = list[i]
+		if is_server_protocol_compat(fav.proto_min, fav.proto_max) then
+			table.insert(res, fav)
+		end
+	end
+	for i=1,#list,1 do
+		local fav = list[i]
+		if not is_server_protocol_compat(fav.proto_min, fav.proto_max) then
+			table.insert(res, fav)
+		end
+	end
+	return res
+end
+
 --------------------------------------------------------------------------------
 function render_favorite(spec,render_details)
 	local text = ""
@@ -68,6 +93,7 @@ function render_favorite(spec,render_details)
 	end
 
 	local details = ""
+	local grey_out = not is_server_protocol_compat(spec.proto_max, spec.proto_min)
 
 	if spec.clients ~= nil and spec.clients_max ~= nil then
 		local clients_color = ''
@@ -87,11 +113,17 @@ function render_favorite(spec,render_details)
 			clients_color = '#ffba97' -- 90-100%: orange
 		end
 
+		if grey_out then
+			clients_color = '#aaaaaa'
+		end
+
 		details = details ..
 				clients_color .. ',' ..
 				render_client_count(spec.clients) .. ',' ..
 				'/,' ..
 				render_client_count(spec.clients_max) .. ','
+	elseif grey_out then
+		details = details .. '#aaaaaa,?,/,?,'
 	else
 		details = details .. ',?,/,?,'
 	end
@@ -114,7 +146,7 @@ function render_favorite(spec,render_details)
 		details = details .. "0,"
 	end
 
-	return details .. text
+	return details .. (grey_out and '#aaaaaa,' or ',') .. text
 end
 
 --------------------------------------------------------------------------------
@@ -195,7 +227,7 @@ function asyncOnlineFavourites()
 		nil,
 		function(result)
 			if core.setting_getbool("public_serverlist") then
-				menudata.favorites = result
+				menudata.favorites = order_favorite_list(result)
 				core.event_handler("Refresh")
 			end
 		end
@@ -225,3 +257,21 @@ function text2textlist(xpos,ypos,width,height,tl_name,textlen,text,transparency)
 
 	return retval
 end
+
+--------------------------------------------------------------------------------
+function is_server_protocol_compat(proto_min, proto_max)
+	return not ((min_supp_proto > (proto_max or 24)) or (max_supp_proto < (proto_min or 13)))
+end
+--------------------------------------------------------------------------------
+function is_server_protocol_compat_or_error(proto_min, proto_max)
+	if not is_server_protocol_compat(proto_min, proto_max) then
+		gamedata.errormessage = fgettext_ne("Protocol version mismatch, server " ..
+			((proto_min ~= proto_max) and "supports protocols between $1 and $2" or "enforces protocol version $1") ..
+			", we " ..
+			((min_supp_proto ~= max_supp_proto) and "support protocols between version $3 and $4." or "only support protocol version $3"),
+			proto_min or 13, proto_max or 24, min_supp_proto, max_supp_proto)
+		return false
+	end
+
+	return true
+end

builtin/mainmenu/tab_multiplayer.lua

@@ -62,6 +62,7 @@ local function get_formspec(tabview, name, tabdata)
 			image_column(fgettext("Creative mode"), "creative") .. ",padding=1;" ..
 			image_column(fgettext("Damage enabled"), "damage") .. ",padding=0.25;" ..
 			image_column(fgettext("PvP enabled"), "pvp") .. ",padding=0.25;" ..
+			"color,span=1;" ..
 			"text,padding=1]"                               -- name
 	else
 		retval = retval .. "tablecolumns[text]"
@@ -88,7 +89,6 @@ end
 
 --------------------------------------------------------------------------------
 local function main_button_handler(tabview, fields, name, tabdata)
-
 	if fields["te_name"] ~= nil then
 		gamedata.playername = fields["te_name"]
 		core.setting_set("name", fields["te_name"])
@@ -98,6 +98,10 @@ local function main_button_handler(tabview, fields, name, tabdata)
 		local event = core.explode_table_event(fields["favourites"])
 		if event.type == "DCL" then
 			if event.row <= #menudata.favorites then
+				if not is_server_protocol_compat_or_error(menudata.favorites[event.row].proto_min,
+						menudata.favorites[event.row].proto_max) then
+					return true
+				end
 				gamedata.address    = menudata.favorites[event.row].address
 				gamedata.port       = menudata.favorites[event.row].port
 				gamedata.playername = fields["te_name"]
@@ -189,7 +193,7 @@ local function main_button_handler(tabview, fields, name, tabdata)
 		local current_favourite = core.get_table_index("favourites")
 		if current_favourite == nil then return end
 		core.delete_favorite(current_favourite)
-		menudata.favorites   = core.get_favorites()
+		menudata.favorites = order_favorite_list(core.get_favorites())
 		tabdata.fav_selected = nil
 
 		core.setting_set("address","")
@@ -215,6 +219,11 @@ local function main_button_handler(tabview, fields, name, tabdata)
 
 			gamedata.servername        = menudata.favorites[fav_idx].name
 			gamedata.serverdescription = menudata.favorites[fav_idx].description
+
+			if not is_server_protocol_compat_or_error(menudata.favorites[fav_idx].proto_min,
+					menudata.favorites[fav_idx].proto_max)then
+				return true
+			end
 		else
 			gamedata.servername        = ""
 			gamedata.serverdescription = ""

builtin/mainmenu/tab_simple_main.lua

@@ -45,6 +45,7 @@ local function get_formspec(tabview, name, tabdata)
 			image_column(fgettext("Creative mode"), "creative") .. ",padding=1;" ..
 			image_column(fgettext("Damage enabled"), "damage") .. ",padding=0.25;" ..
 			image_column(fgettext("PvP enabled"), "pvp") .. ",padding=0.25;" ..
+			"color,span=1;" ..
 			"text,padding=1]"                               -- name
 	else
 		retval = retval .. "tablecolumns[text]"
@@ -87,7 +88,6 @@ local function get_formspec(tabview, name, tabdata)
 end
 
 --------------------------------------------------------------------------------
-
 local function main_button_handler(tabview, fields, name, tabdata)
 
 	if fields["btn_start_singleplayer"] then
@@ -159,6 +159,11 @@ local function main_button_handler(tabview, fields, name, tabdata)
 
 			gamedata.servername			= menudata.favorites[fav_idx].name
 			gamedata.serverdescription	= menudata.favorites[fav_idx].description
+
+			if not is_server_protocol_compat_or_error(menudata.favorites[fav_idx].proto_min,
+					menudata.favorites[fav_idx].proto_max) then
+				return true
+			end
 		else
 			gamedata.servername			= ""
 			gamedata.serverdescription	= ""