Expose client version information in non-debug builds

builtin/game/init.lua

@@ -8,6 +8,7 @@ local gamepath   = scriptpath .. "game".. DIR_DELIM
 local builtin_shared = {}
 
 dofile(gamepath .. "constants.lua")
+dofile(gamepath .. "protocol_versions.lua")
 assert(loadfile(commonpath .. "item_s.lua"))(builtin_shared)
 assert(loadfile(gamepath .. "item.lua"))(builtin_shared)
 assert(loadfile(commonpath .. "register.lua"))(builtin_shared)

builtin/game/protocol_versions.lua

@@ -0,0 +1,16 @@
+-- c.f. https://content.luanti.org/api/minetest_versions/
+-- see also src/network/networkprotocol.cpp
+core.protocol_versions = {
+	["5.0"] = 37,
+	["5.1"] = 38,
+	["5.2"] = 39,
+	["5.3"] = 39,
+	["5.4"] = 39,
+	["5.5"] = 40,
+	["5.6"] = 41,
+	["5.7"] = 42,
+	["5.8"] = 43,
+	["5.9"] = 44,
+	["5.10"] = 46,
+	["5.11"] = 47,
+}

doc/lua_api.md

@@ -5716,17 +5716,32 @@ Utilities
       min_jitter = 0.01,         -- minimum packet time jitter
       max_jitter = 0.5,          -- maximum packet time jitter
       avg_jitter = 0.03,         -- average packet time jitter
+
+      -- The version information is provided by the client and may be spoofed
+      -- or inconsistent in engine forks. You must not use this for checking
+      -- feature availability of clients. Instead, do use the fields
+      -- `protocol_version` and `formspec_version` where it matters.
+      -- You can use `core.protocol_versions` to map Luanti versions to protocol versions.
+      -- This version string may only be used for analysis purposes.
+      version_string = "0.4.9-git",   -- full version string
+
       -- the following information is available in a debug build only!!!
       -- DO NOT USE IN MODS
       --serialization_version = 26,     -- serialization version used by client
       --major = 0,                      -- major version number
       --minor = 4,                      -- minor version number
       --patch = 10,                     -- patch version number
-      --version_string = "0.4.9-git",   -- full version string
       --state = "Active"                -- current client state
   }
   ```
 
+* `core.protocol_versions`:
+  * Table mapping minor Luanti 5.x versions to
+    corresponding protocol versions for modder convenience.
+  * For example, to check whether a client has at least the feature set
+    of Luanti 5.8 or newer, you could do:
+    `core.get_player_information(player_name).protocol_version >= core.protocol_versions["5.8"]`
+  * Available since 5.11
 * `core.get_player_window_information(player_name)`:
 
   ```lua

src/network/networkprotocol.cpp

@@ -64,6 +64,7 @@
 		[scheduled bump for 5.11.0]
 */
 
+// Note: Also update builtin/game/protocol_versions.lua when bumping
 const u16 LATEST_PROTOCOL_VERSION = 47;
 
 // See also formspec [Version History] in doc/lua_api.md

src/script/lua_api/l_server.cpp

@@ -239,6 +239,10 @@ int ModApiServer::l_get_player_information(lua_State *L)
 	lua_pushstring(L, info.lang_code.c_str());
 	lua_settable(L, table);
 
+	lua_pushstring(L,"version_string");
+	lua_pushstring(L, info.vers_string.c_str());
+	lua_settable(L, table);
+
 #ifndef NDEBUG
 	lua_pushstring(L,"serialization_version");
 	lua_pushnumber(L, info.ser_vers);
@@ -256,10 +260,6 @@ int ModApiServer::l_get_player_information(lua_State *L)
 	lua_pushnumber(L, info.patch);
 	lua_settable(L, table);
 
-	lua_pushstring(L,"version_string");
-	lua_pushstring(L, info.vers_string.c_str());
-	lua_settable(L, table);
-
 	lua_pushstring(L,"state");
 	lua_pushstring(L, ClientInterface::state2Name(info.state).c_str());
 	lua_settable(L, table);