Allow dynamic_add_media at mod load time

.gitignore

@@ -92,11 +92,8 @@ cmake_install.cmake
 CMakeCache.txt
 CPackConfig.cmake
 CPackSourceConfig.cmake
-src/test_config.h
 src/cmake_config.h
 src/cmake_config_githash.h
-src/unittest/test_world/world.mt
-games/devtest/mods/testnodes/textures/testnodes_generated_*.png
 /locale/
 .directory
 *.cbp

builtin/game/features.lua

@@ -35,6 +35,7 @@ core.features = {
 	wallmounted_rotate = true,
 	item_specific_pointabilities = true,
 	blocking_pointability_type = true,
+	dynamic_add_media_startup = true,
 }
 
 function core.has_feature(arg)

doc/lua_api.md

@@ -5304,6 +5304,8 @@ Utilities
       item_specific_pointabilities = true,
       -- Nodes `pointable` property can be `"blocking"` (5.9.0)
       blocking_pointability_type = true,
+      -- dynamic_add_media can be called at startup when leaving callback as `nil` (5.9.0)
+      dynamic_add_media_startup = true,
   }
   ```
 
@@ -6621,6 +6623,9 @@ Server
         name twice is not possible/guaranteed to work. An exception to this is the
         use of `to_player` to send the same, already existent file to multiple
         chosen players.
+      * You can also call this at startup time. In that case `callback` MUST
+        be `nil` and you cannot use `ephemeral` or `to_player`, as these logically
+        do not make sense.
     * Clients will attempt to fetch files added this way via remote media,
       this can make transfer of bigger files painless (if set up). Nevertheless
       it is advised not to use dynamic media for big media files.

games/devtest/mods/testnodes/textures.lua

@@ -149,15 +149,25 @@ fractal = nil
 frac_emb = nil
 checker = nil
 
-local textures_path = minetest.get_modpath( minetest.get_current_modname() ) .. "/textures/"
+do
-minetest.safe_file_write(
+	-- we used to write the textures to our mod folder. in order to avoid
+	-- duplicate errors delete them if they still exist.
+	local path = core.get_modpath(core.get_current_modname()) .. "/textures/"
+	os.remove(path .. "testnodes_generated_mb.png")
+	os.remove(path .. "testnodes_generated_ck.png")
+end
+
+local textures_path = core.get_worldpath() .. "/"
+core.safe_file_write(
 	textures_path .. "testnodes_generated_mb.png",
 	encode_and_check(512, 512, "rgb", data_mb)
 )
-minetest.safe_file_write(
+core.safe_file_write(
 	textures_path .. "testnodes_generated_ck.png",
 	encode_and_check(512, 512, "gray", data_ck)
 )
+core.dynamic_add_media(textures_path .. "testnodes_generated_mb.png")
+core.dynamic_add_media(textures_path .. "testnodes_generated_ck.png")
 
 minetest.register_node("testnodes:generated_png_mb", {
 	description = S("Generated Mandelbrot PNG Test Node"),

src/script/lua_api/l_server.cpp

@@ -545,9 +545,8 @@ int ModApiServer::l_dynamic_add_media(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;
 
-	if (!getEnv(L))
-		throw LuaError("Dynamic media cannot be added before server has started up");
 	Server *server = getServer(L);
+	const bool at_startup = !getEnv(L);
 
 	std::string filepath;
 	std::string to_player;
@@ -562,7 +561,16 @@ int ModApiServer::l_dynamic_add_media(lua_State *L)
 	}
 	if (filepath.empty())
 		luaL_typerror(L, 1, "non-empty string");
-	luaL_checktype(L, 2, LUA_TFUNCTION);
+	if (at_startup) {
+		if (!lua_isnoneornil(L, 2))
+			throw LuaError("must be called without callback at load-time");
+		// In order to keep edge cases to a minimum actually use an empty function.
+		int err = luaL_loadstring(L, "");
+		SANITY_CHECK(err == 0);
+		lua_replace(L, 2);
+	} else {
+		luaL_checktype(L, 2, LUA_TFUNCTION);
+	}
 
 	CHECK_SECURE_PATH(L, filepath.c_str(), false);
 

src/server.cpp

@@ -3582,6 +3582,13 @@ bool Server::dynamicAddMedia(std::string filepath,
 		}
 	}
 
+	if (!m_env && (!to_player.empty() || ephemeral)) {
+		errorstream << "Server::dynamicAddMedia(): "
+			"adding ephemeral or player-specific media at startup is nonsense"
+			<< std::endl;
+		return false;
+	}
+
 	// Load the file and add it to our media cache
 	std::string filedata, raw_hash;
 	bool ok = addMediaFile(filename, filepath, &filedata, &raw_hash);
@@ -3618,19 +3625,20 @@ bool Server::dynamicAddMedia(std::string filepath,
 		m_media[filename].no_announce = true;
 	}
 
-	// Push file to existing clients
-	NetworkPacket pkt(TOCLIENT_MEDIA_PUSH, 0);
-	pkt << raw_hash << filename << (bool)ephemeral;
-
-	NetworkPacket legacy_pkt = pkt;
-
-	// Newer clients get asked to fetch the file (asynchronous)
-	pkt << token;
-	// Older clients have an awful hack that just throws the data at them
-	legacy_pkt.putLongString(filedata);
-
 	std::unordered_set<session_t> delivered, waiting;
-	{
+
+	// Push file to existing clients
+	if (m_env) {
+		NetworkPacket pkt(TOCLIENT_MEDIA_PUSH, 0);
+		pkt << raw_hash << filename << static_cast<bool>(ephemeral);
+
+		NetworkPacket legacy_pkt = pkt;
+
+		// Newer clients get asked to fetch the file (asynchronous)
+		pkt << token;
+		// Older clients have an awful hack that just throws the data at them
+		legacy_pkt.putLongString(filedata);
+
 		ClientInterface::AutoLock clientlock(m_clients);
 		for (auto &pair : m_clients.getClientList()) {
 			if (pair.second->getState() == CS_DefinitionsSent && !ephemeral) {