creative: Update for compatibility with minetest.creative_is_enabled (#2691)

game_api.txt

@@ -93,11 +93,9 @@ For example,
 is used to show all tools. Name is used in the sfinv page name, title is the
 human readable title.
 
-`is_enabled_for` is used to check whether a player is in creative mode:
-
-    creative.is_enabled_for(name)
-
-Override this to allow per-player game modes.
+Creative provides `creative.is_enabled_for(name)`, which is identical in
+functionality to the engine's `minetest.creative_is_enabled(name)`.
+Its use is deprecated and it should also not be overriden.
 
 The contents of `creative.formspec_add` is appended to every creative inventory
 page. Mods can use it to add additional formspec elements onto the default

mods/creative/init.lua

@@ -27,16 +27,25 @@ minetest.register_privilege("creative", {
 	on_revoke = update_sfinv,
 })
 
-local creative_mode_cache = minetest.settings:get_bool("creative_mode")
+-- Override the engine's creative mode function
+local old_is_creative_enabled = minetest.is_creative_enabled
 
+function minetest.is_creative_enabled(name)
+	if name == "" then
+		return old_is_creative_enabled(name)
+	end
+	return minetest.check_player_privs(name, {creative = true}) or
+		old_is_creative_enabled(name)
+end
+
+-- For backwards compatibility:
 function creative.is_enabled_for(name)
-	return creative_mode_cache or
-		minetest.check_player_privs(name, {creative = true})
+	return minetest.is_creative_enabled(name)
 end
 
 dofile(minetest.get_modpath("creative") .. "/inventory.lua")
 
-if creative_mode_cache then
+if minetest.is_creative_enabled("") then
 	-- Dig time is modified according to difference (leveldiff) between tool
 	-- 'maxlevel' and node 'level'. Digtime is divided by the larger of
 	-- leveldiff and 1.