Allow image formats other than PNG for game backgrounds in the main menu (#16395)

.luacheckrc

@@ -23,7 +23,7 @@ read_globals = {
 	"tracy",
 
 	string = {fields = {"split", "trim"}},
-	table  = {fields = {"copy", "copy_with_metatables", "getn", "indexof", "keyof", "insert_all"}},
+	table  = {fields = {"copy", "copy_with_metatables", "getn", "indexof", "keyof", "insert_all", "shuffle"}},
 	math   = {fields = {"hypot", "round"}},
 }
 

builtin/common/misc_helpers.lua

@@ -119,6 +119,9 @@ end
 -- }]]
 function dump(value, indent)
 	indent = indent or "\t"
+
+	assert(type(indent) == "string", "dump()'s second argument should be a string or nil.")
+
 	local newline = indent == "" and "" or "\n"
 
 	local rope = {}
@@ -873,3 +876,4 @@ function core.parse_coordinates(x, y, z, relative_to)
 	local rz = core.parse_relative_number(z, relative_to.z)
 	return rx and ry and rz and vector.new(rx, ry, rz)
 end
+

builtin/game/chat.lua

@@ -43,7 +43,7 @@ end
 -- Chat command handler
 --
 
-core.chatcommands = core.registered_chatcommands -- BACKWARDS COMPATIBILITY
+core.chatcommands = core.registered_chatcommands -- backwards compatibility
 
 local msg_time_threshold =
 	tonumber(core.settings:get("chatcommand_msg_time_threshold")) or 0.1

builtin/mainmenu/game_theme.lua

@@ -2,7 +2,6 @@
 -- Copyright (C) 2013 sapier
 -- SPDX-License-Identifier: LGPL-2.1-or-later
 
-
 mm_game_theme = {}
 
 --------------------------------------------------------------------------------
@@ -86,16 +85,24 @@ function mm_game_theme.clear_single(identifier)
 	core.set_background(identifier, "")
 end
 
+--------------------------------------------------------------------------------
+local valid_image_extensions = {
+	".png",
+	".jpg",
+	".jpeg",
+}
+
 --------------------------------------------------------------------------------
 function mm_game_theme.set_engine_single(identifier)
 	--try texture pack first
 	if mm_game_theme.texturepack ~= nil then
-		local path = mm_game_theme.texturepack .. DIR_DELIM .."menu_" ..
-										identifier .. ".png"
+		for _, extension in pairs(valid_image_extensions) do
+			local path = mm_game_theme.texturepack .. DIR_DELIM .. "menu_" .. identifier .. extension
 			if core.set_background(identifier, path) then
 				return true
 			end
 		end
+	end
 
 	local path = defaulttexturedir .. DIR_DELIM .. "menu_" .. identifier .. ".png"
 	if core.set_background(identifier, path) then
@@ -106,12 +113,16 @@ function mm_game_theme.set_engine_single(identifier)
 end
 
 --------------------------------------------------------------------------------
+
+
 function mm_game_theme.set_game_single(identifier, gamedetails)
+	local extensions_randomised = table.copy(valid_image_extensions)
+	table.shuffle(extensions_randomised)
+	for _, extension in pairs(extensions_randomised) do
 		assert(gamedetails ~= nil)
 
 		if mm_game_theme.texturepack ~= nil then
-		local path = mm_game_theme.texturepack .. DIR_DELIM ..
-			gamedetails.id .. "_menu_" .. identifier .. ".png"
+			local path = mm_game_theme.texturepack .. DIR_DELIM .. gamedetails.id .. "_menu_" .. identifier .. extension
 			if core.set_background(identifier, path) then
 				return true
 			end
@@ -122,7 +133,7 @@ function mm_game_theme.set_game_single(identifier, gamedetails)
 		local filename
 		local menu_files = core.get_dir_list(gamedetails.path .. DIR_DELIM .. "menu", false)
 		for i = 1, #menu_files do
-		filename = identifier .. "." .. i .. ".png"
+			filename = identifier .. "." .. i .. extension
 			if table.indexof(menu_files, filename) == -1 then
 				n = i - 1
 				break
@@ -131,17 +142,17 @@ function mm_game_theme.set_game_single(identifier, gamedetails)
 		-- Select random texture, 0 means standard texture
 		n = math.random(0, n)
 		if n == 0 then
-		filename = identifier .. ".png"
+			filename = identifier .. extension
 		else
-		filename = identifier .. "." .. n .. ".png"
+			filename = identifier .. "." .. n .. extension
 		end
 
-	local path = gamedetails.path .. DIR_DELIM .. "menu" ..
-		DIR_DELIM .. filename
+		local path = gamedetails.path .. DIR_DELIM .. "menu" .. DIR_DELIM .. filename
 		if core.set_background(identifier, path) then
 			return true
 		end
 
+	end
 	return false
 end