HUD: Reject and warn on invalid stat types (minetest#11548)

This comes into play on older servers which do not know the "stat" type.
Warnings are only logged once to avoid spam within globalstep callbacks

src/network/clientpackethandler.cpp

@@ -1119,17 +1119,29 @@ void Client::handleCommand_HudChange(NetworkPacket* pkt)
 
 	*pkt >> server_id >> stat;
 
-	if (stat == HUD_STAT_POS || stat == HUD_STAT_SCALE ||
-		stat == HUD_STAT_ALIGN || stat == HUD_STAT_OFFSET)
-		*pkt >> v2fdata;
-	else if (stat == HUD_STAT_NAME || stat == HUD_STAT_TEXT || stat == HUD_STAT_TEXT2)
-		*pkt >> sdata;
-	else if (stat == HUD_STAT_WORLD_POS)
-		*pkt >> v3fdata;
-	else if (stat == HUD_STAT_SIZE)
-		*pkt >> v2s32data;
-	else
-		*pkt >> intdata;
+	// Keep in sync with:server.cpp -> SendHUDChange
+	switch ((HudElementStat)stat) {
+		case HUD_STAT_POS:
+		case HUD_STAT_SCALE:
+		case HUD_STAT_ALIGN:
+		case HUD_STAT_OFFSET:
+			*pkt >> v2fdata;
+			break;
+		case HUD_STAT_NAME:
+		case HUD_STAT_TEXT:
+		case HUD_STAT_TEXT2:
+			*pkt >> sdata;
+			break;
+		case HUD_STAT_WORLD_POS:
+			*pkt >> v3fdata;
+			break;
+		case HUD_STAT_SIZE:
+			*pkt >> v2s32data;
+			break;
+		default:
+			*pkt >> intdata;
+			break;
+	}
 
 	ClientEvent *event = new ClientEvent();
 	event->type                 = CE_HUDCHANGE;

src/script/common/c_content.cpp

@@ -1989,15 +1989,17 @@ void push_hud_element(lua_State *L, HudElement *elem)
 	lua_setfield(L, -2, "style");
 }
 
-HudElementStat read_hud_change(lua_State *L, HudElement *elem, void **value)
+bool read_hud_change(lua_State *L, HudElementStat &stat, HudElement *elem, void **value)
 {
-	HudElementStat stat = HUD_STAT_NUMBER;
-	std::string statstr;
-	if (lua_isstring(L, 3)) {
+	std::string statstr = lua_tostring(L, 3);
+	{
 		int statint;
-		statstr = lua_tostring(L, 3);
-		stat = string_to_enum(es_HudElementStat, statint, statstr) ?
-				(HudElementStat)statint : stat;
+		if (!string_to_enum(es_HudElementStat, statint, statstr)) {
+			script_log_unique(L, "Unknown HUD stat type: " + statstr, warningstream);
+			return false;
+		}
+
+		stat = (HudElementStat)statint;
 	}
 
 	switch (stat) {
@@ -2060,7 +2062,8 @@ HudElementStat read_hud_change(lua_State *L, HudElement *elem, void **value)
 			*value = &elem->style;
 			break;
 	}
-	return stat;
+
+	return true;
 }
 
 /******************************************************************************/

src/script/common/c_content.h

@@ -193,12 +193,12 @@ void               read_json_value           (lua_State *L, Json::Value &root,
 void push_pointed_thing(lua_State *L, const PointedThing &pointed, bool csm =
 	false, bool hitpoint = false);
 
-void               push_objectRef            (lua_State *L, const u16 id);
+void push_objectRef            (lua_State *L, const u16 id);
 
-void               read_hud_element          (lua_State *L, HudElement *elem);
+void read_hud_element          (lua_State *L, HudElement *elem);
 
-void               push_hud_element          (lua_State *L, HudElement *elem);
+void push_hud_element          (lua_State *L, HudElement *elem);
 
-HudElementStat     read_hud_change           (lua_State *L, HudElement *elem, void **value);
+bool read_hud_change           (lua_State *L, HudElementStat &stat, HudElement *elem, void **value);
 
-void               push_collision_move_result(lua_State *L, const collisionMoveResult &res);
+void push_collision_move_result(lua_State *L, const collisionMoveResult &res);

src/script/common/c_internal.cpp

@@ -18,10 +18,12 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 */
 
 #include "common/c_internal.h"
+#include "util/numeric.h"
 #include "debug.h"
 #include "log.h"
 #include "porting.h"
 #include "settings.h"
+#include <algorithm> // std::find
 
 std::string script_get_backtrace(lua_State *L)
 {
@@ -135,24 +137,35 @@ void script_run_callbacks_f(lua_State *L, int nargs,
 	lua_remove(L, error_handler);
 }
 
-static void script_log(lua_State *L, const std::string &message,
-	std::ostream &log_to, bool do_error, int stack_depth)
+static void script_log_add_source(lua_State *L, std::string &message, int stack_depth)
 {
 	lua_Debug ar;
 
-	log_to << message << " ";
 	if (lua_getstack(L, stack_depth, &ar)) {
 		FATAL_ERROR_IF(!lua_getinfo(L, "Sl", &ar), "lua_getinfo() failed");
-		log_to << "(at " << ar.short_src << ":" << ar.currentline << ")";
+		message.append(" (at " + std::string(ar.short_src) + ":"
+			+ std::to_string(ar.currentline) + ")");
 	} else {
-		log_to << "(at ?:?)";
+		message.append(" (at ?:?)");
 	}
-	log_to << std::endl;
+}
 
-	if (do_error)
-		script_error(L, LUA_ERRRUN, NULL, NULL);
-	else
-		infostream << script_get_backtrace(L) << std::endl;
+bool script_log_unique(lua_State *L, std::string message, std::ostream &log_to,
+	int stack_depth)
+{
+	thread_local std::vector<u64> logged_messages;
+
+	script_log_add_source(L, message, stack_depth);
+	u64 hash = murmur_hash_64_ua(message.data(), message.length(), 0xBADBABE);
+
+	if (std::find(logged_messages.begin(), logged_messages.end(), hash)
+			== logged_messages.end()) {
+
+		logged_messages.emplace_back(hash);
+		log_to << message << std::endl;
+		return true;
+	}
+	return false;
 }
 
 DeprecatedHandlingMode get_deprecated_handling_mode()
@@ -174,9 +187,18 @@ DeprecatedHandlingMode get_deprecated_handling_mode()
 	return ret;
 }
 
-void log_deprecated(lua_State *L, const std::string &message, int stack_depth)
+void log_deprecated(lua_State *L, std::string message, int stack_depth)
 {
 	DeprecatedHandlingMode mode = get_deprecated_handling_mode();
-	if (mode != DeprecatedHandlingMode::Ignore)
-		script_log(L, message, warningstream, mode == DeprecatedHandlingMode::Error, stack_depth);
+	if (mode == DeprecatedHandlingMode::Ignore)
+		return;
+
+	script_log_add_source(L, message, stack_depth);
+	warningstream << message << std::endl;
+
+	if (mode == DeprecatedHandlingMode::Error)
+		script_error(L, LUA_ERRRUN, NULL, NULL);
+	else
+		infostream << script_get_backtrace(L) << std::endl;
 }
+

src/script/common/c_internal.h

@@ -114,6 +114,9 @@ void script_error(lua_State *L, int pcall_result, const char *mod, const char *f
 void script_run_callbacks_f(lua_State *L, int nargs,
 	RunCallbacksMode mode, const char *fxn);
 
+bool script_log_unique(lua_State *L, std::string message, std::ostream &log_to,
+	int stack_depth = 1);
+
 enum class DeprecatedHandlingMode {
 	Ignore,
 	Log,
@@ -134,5 +137,4 @@ DeprecatedHandlingMode get_deprecated_handling_mode();
  * @param message The deprecation method
  * @param stack_depth How far on the stack to the first user function (ie: not builtin or core)
  */
-void log_deprecated(lua_State *L, const std::string &message,
-	int stack_depth=1);
+void log_deprecated(lua_State *L, std::string message, int stack_depth = 1);

src/script/lua_api/l_localplayer.cpp

@@ -369,10 +369,11 @@ int LuaLocalPlayer::l_hud_change(lua_State *L)
 	if (!element)
 		return 0;
 
+	HudElementStat stat;
 	void *unused;
-	read_hud_change(L, element, &unused);
+	bool ok = read_hud_change(L, stat, element, &unused);
 
-	lua_pushboolean(L, true);
+	lua_pushboolean(L, ok);
 	return 1;
 }
 

src/script/lua_api/l_object.cpp

@@ -1555,12 +1555,14 @@ int ObjectRef::l_hud_change(lua_State *L)
 	if (elem == nullptr)
 		return 0;
 
+	HudElementStat stat;
 	void *value = nullptr;
-	HudElementStat stat = read_hud_change(L, elem, &value);
+	bool ok = read_hud_change(L, stat, elem, &value);
 
-	getServer(L)->hudChange(player, id, stat, value);
+	if (ok)
+		getServer(L)->hudChange(player, id, stat, value);
 
-	lua_pushboolean(L, true);
+	lua_pushboolean(L, ok);
 	return 1;
 }