Pass a errfunc to lua_pcall to get a traceback

src/script/common/c_content.cpp

@@ -871,6 +871,8 @@ void read_groups(lua_State *L, int index,
 /******************************************************************************/
 void push_items(lua_State *L, const std::vector<ItemStack> &items)
 {
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
 	// Get the table insert function
 	lua_getglobal(L, "table");
 	lua_getfield(L, -1, "insert");
@@ -883,11 +885,12 @@ void push_items(lua_State *L, const std::vector<ItemStack> &items)
 		lua_pushvalue(L, table_insert);
 		lua_pushvalue(L, table);
 		LuaItemStack::create(L, item);
-		if(lua_pcall(L, 2, 0, 0))
+		if(lua_pcall(L, 2, 0, errorhandler))
-			script_error(L, "error: %s", lua_tostring(L, -1));
+			script_error(L);
 	}
-	lua_remove(L, -2); // Remove table
 	lua_remove(L, -2); // Remove insert
+	lua_remove(L, -2); // Remove table
+	lua_remove(L, -2); // Remove error handler
 }
 
 /******************************************************************************/

src/script/common/c_internal.cpp

@@ -23,32 +23,41 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 std::string script_get_backtrace(lua_State *L)
 {
 	std::string s;
-	lua_getfield(L, LUA_GLOBALSINDEX, "debug");
+	lua_getglobal(L, "debug");
 	if(lua_istable(L, -1)){
 		lua_getfield(L, -1, "traceback");
 		if(lua_isfunction(L, -1)) {
 			lua_call(L, 0, 1);
 			if(lua_isstring(L, -1)){
-				s += lua_tostring(L, -1);
+				s = lua_tostring(L, -1);
+			}
 		}
 		lua_pop(L, 1);
 	}
-		else{
-			lua_pop(L, 1);
-		}
-	}
 	lua_pop(L, 1);
 	return s;
 }
 
-void script_error(lua_State *L, const char *fmt, ...)
+int script_error_handler(lua_State *L) {
+	lua_getglobal(L, "debug");
+	if (!lua_istable(L, -1)) {
+		lua_pop(L, 1);
+		return 1;
+	}
+	lua_getfield(L, -1, "traceback");
+	if (!lua_isfunction(L, -1)) {
+		lua_pop(L, 2);
+		return 1;
+	}
+	lua_pushvalue(L, 1);
+	lua_pushinteger(L, 2);
+	lua_call(L, 2, 1);
+	return 1;
+}
+
+void script_error(lua_State *L)
 {
-	va_list argp;
+	throw LuaError(NULL, lua_tostring(L, -1));
-	va_start(argp, fmt);
-	char buf[10000];
-	vsnprintf(buf, 10000, fmt, argp);
-	va_end(argp);
-	throw LuaError(L, buf);
 }
 
 // Push the list of callbacks (a lua table).
@@ -61,13 +70,20 @@ void script_run_callbacks(lua_State *L, int nargs, RunCallbacksMode mode)
 {
 	// Insert the return value into the lua stack, below the table
 	assert(lua_gettop(L) >= nargs + 1);
-	lua_pushnil(L);
-	lua_insert(L, -(nargs + 1) - 1);
-	// Stack now looks like this:
-	// ... <return value = nil> <table> <arg#1> <arg#2> ... <arg#n>
 
+	lua_pushnil(L);
 	int rv = lua_gettop(L) - nargs - 1;
-	int table = rv + 1;
+	lua_insert(L, rv);
+
+	// Insert error handler after return value
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = rv + 1;
+	lua_insert(L, errorhandler);
+
+	// Stack now looks like this:
+	// ... <return value = nil> <error handler> <table> <arg#1> <arg#2> ... <arg#n>
+
+	int table = errorhandler + 1;
 	int arg = table + 1;
 
 	luaL_checktype(L, table, LUA_TTABLE);
@@ -81,8 +97,8 @@ void script_run_callbacks(lua_State *L, int nargs, RunCallbacksMode mode)
 		// Call function
 		for(int i = 0; i < nargs; i++)
 			lua_pushvalue(L, arg+i);
-		if(lua_pcall(L, nargs, 1, 0))
+		if(lua_pcall(L, nargs, 1, errorhandler))
-			script_error(L, "error: %s", lua_tostring(L, -1));
+			script_error(L);
 
 		// Move return value to designated space in stack
 		// Or pop it

src/script/common/c_internal.h

@@ -65,7 +65,8 @@ enum RunCallbacksMode
 };
 
 std::string script_get_backtrace(lua_State *L);
-void        script_error           (lua_State *L, const char *fmt, ...);
+int script_error_handler(lua_State *L);
+void script_error(lua_State *L);
 void script_run_callbacks(lua_State *L, int nargs,
 		RunCallbacksMode mode);
 

src/script/common/c_types.cpp

@@ -25,9 +25,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 LuaError::LuaError(lua_State *L, const std::string &s)
 {
-	m_s = "LuaError: ";
+	m_s = "LuaError: " + s;
-	m_s += s + "\n";
+	if (L) m_s += '\n' + script_get_backtrace(L);
-	m_s += script_get_backtrace(L);
 }
 
 struct EnumString es_ItemType[] =

src/script/cpp_api/s_base.cpp

@@ -55,23 +55,6 @@ public:
 	}
 };
 
-static int loadScript_ErrorHandler(lua_State *L) {
-	lua_getfield(L, LUA_GLOBALSINDEX, "debug");
-	if (!lua_istable(L, -1)) {
-		lua_pop(L, 1);
-		return 1;
-	}
-	lua_getfield(L, -1, "traceback");
-	if (!lua_isfunction(L, -1)) {
-		lua_pop(L, 2);
-		return 1;
-	}
-	lua_pushvalue(L, 1);
-	lua_pushinteger(L, 2);
-	lua_call(L, 2, 1);
-	return 1;
-}
-
 
 /*
 	ScriptApiBase
@@ -133,7 +116,7 @@ bool ScriptApiBase::loadScript(const std::string &scriptpath)
 
 	lua_State *L = getStack();
 
-	lua_pushcfunction(L, loadScript_ErrorHandler);
+	lua_pushcfunction(L, script_error_handler);
 	int errorhandler = lua_gettop(L);
 
 	int ret = luaL_loadfile(L, scriptpath.c_str()) || lua_pcall(L, 0, 0, errorhandler);
@@ -159,19 +142,13 @@ void ScriptApiBase::realityCheck()
 	if(top >= 30){
 		dstream<<"Stack is over 30:"<<std::endl;
 		stackDump(dstream);
-		scriptError("Stack is over 30 (reality check)");
+		throw LuaError(m_luastack, "Stack is over 30 (reality check)");
 	}
 }
 
-void ScriptApiBase::scriptError(const char *fmt, ...)
+void ScriptApiBase::scriptError()
 {
-	va_list argp;
+	throw LuaError(NULL, lua_tostring(m_luastack, -1));
-	va_start(argp, fmt);
-	char buf[10000];
-	vsnprintf(buf, 10000, fmt, argp);
-	va_end(argp);
-	//errorstream<<"SCRIPT ERROR: "<<buf;
-	throw LuaError(m_luastack, buf);
 }
 
 void ScriptApiBase::stackDump(std::ostream &o)

src/script/cpp_api/s_base.h

@@ -31,6 +31,7 @@ extern "C" {
 #include "jthread/jmutex.h"
 #include "jthread/jmutexautolock.h"
 #include "common/c_types.h"
+#include "common/c_internal.h"
 
 #define SCRIPTAPI_LOCK_DEBUG
 
@@ -65,7 +66,7 @@ protected:
 		{ return m_luastack; }
 
 	void realityCheck();
-	void scriptError(const char *fmt, ...);
+	void scriptError();
 	void stackDump(std::ostream &o);
 
 	Server* getServer() { return m_server; }

src/script/cpp_api/s_entity.cpp

@@ -78,6 +78,9 @@ void ScriptApiEntity::luaentity_Activate(u16 id,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	verbosestream<<"scriptapi_luaentity_activate: id="<<id<<std::endl;
 
 	// Get minetest.luaentities[id]
@@ -85,7 +88,6 @@ void ScriptApiEntity::luaentity_Activate(u16 id,
 	int object = lua_gettop(L);
 
 	// Get on_activate function
-	lua_pushvalue(L, object);
 	lua_getfield(L, -1, "on_activate");
 	if(!lua_isnil(L, -1)) {
 		luaL_checktype(L, -1, LUA_TFUNCTION);
@@ -93,10 +95,12 @@ void ScriptApiEntity::luaentity_Activate(u16 id,
 		lua_pushlstring(L, staticdata.c_str(), staticdata.size());
 		lua_pushinteger(L, dtime_s);
 		// Call with 3 arguments, 0 results
-		if(lua_pcall(L, 3, 0, 0))
+		if(lua_pcall(L, 3, 0, errorhandler))
-			scriptError("error running function on_activate: %s\n",
+			scriptError();
-					lua_tostring(L, -1));
+	} else {
+		lua_pop(L, 1);
 	}
+	lua_pop(L, 2); // Pop object and error handler
 }
 
 void ScriptApiEntity::luaentity_Remove(u16 id)
@@ -123,6 +127,9 @@ std::string ScriptApiEntity::luaentity_GetStaticdata(u16 id)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	//infostream<<"scriptapi_luaentity_get_staticdata: id="<<id<<std::endl;
 
 	// Get minetest.luaentities[id]
@@ -130,7 +137,6 @@ std::string ScriptApiEntity::luaentity_GetStaticdata(u16 id)
 	int object = lua_gettop(L);
 
 	// Get get_staticdata function
-	lua_pushvalue(L, object);
 	lua_getfield(L, -1, "get_staticdata");
 	if(lua_isnil(L, -1))
 		return "";
@@ -138,9 +144,10 @@ std::string ScriptApiEntity::luaentity_GetStaticdata(u16 id)
 	luaL_checktype(L, -1, LUA_TFUNCTION);
 	lua_pushvalue(L, object); // self
 	// Call with 1 arguments, 1 results
-	if(lua_pcall(L, 1, 1, 0))
+	if(lua_pcall(L, 1, 1, errorhandler))
-		scriptError("error running function get_staticdata: %s\n",
+		scriptError();
-				lua_tostring(L, -1));
+	lua_remove(L, object); // Remove object
+	lua_remove(L, errorhandler); // Remove error handler
 
 	size_t len = 0;
 	const char *s = lua_tolstring(L, -1, &len);
@@ -192,6 +199,9 @@ void ScriptApiEntity::luaentity_Step(u16 id, float dtime)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	//infostream<<"scriptapi_luaentity_step: id="<<id<<std::endl;
 
 	// Get minetest.luaentities[id]
@@ -206,8 +216,10 @@ void ScriptApiEntity::luaentity_Step(u16 id, float dtime)
 	lua_pushvalue(L, object); // self
 	lua_pushnumber(L, dtime); // dtime
 	// Call with 2 arguments, 0 results
-	if(lua_pcall(L, 2, 0, 0))
+	if(lua_pcall(L, 2, 0, errorhandler))
-		scriptError("error running function 'on_step': %s\n", lua_tostring(L, -1));
+		scriptError();
+	lua_remove(L, object); // Remove object
+	lua_remove(L, errorhandler); // Remove error handler
 }
 
 // Calls entity:on_punch(ObjectRef puncher, time_from_last_punch,
@@ -218,6 +230,9 @@ void ScriptApiEntity::luaentity_Punch(u16 id,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	//infostream<<"scriptapi_luaentity_step: id="<<id<<std::endl;
 
 	// Get minetest.luaentities[id]
@@ -235,8 +250,10 @@ void ScriptApiEntity::luaentity_Punch(u16 id,
 	push_tool_capabilities(L, *toolcap);
 	push_v3f(L, dir);
 	// Call with 5 arguments, 0 results
-	if(lua_pcall(L, 5, 0, 0))
+	if(lua_pcall(L, 5, 0, errorhandler))
-		scriptError("error running function 'on_punch': %s\n", lua_tostring(L, -1));
+		scriptError();
+	lua_remove(L, object); // Remove object
+	lua_remove(L, errorhandler); // Remove error handler
 }
 
 // Calls entity:on_rightclick(ObjectRef clicker)
@@ -245,6 +262,9 @@ void ScriptApiEntity::luaentity_Rightclick(u16 id,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	//infostream<<"scriptapi_luaentity_step: id="<<id<<std::endl;
 
 	// Get minetest.luaentities[id]
@@ -259,7 +279,9 @@ void ScriptApiEntity::luaentity_Rightclick(u16 id,
 	lua_pushvalue(L, object); // self
 	objectrefGetOrCreate(clicker); // Clicker reference
 	// Call with 2 arguments, 0 results
-	if(lua_pcall(L, 2, 0, 0))
+	if(lua_pcall(L, 2, 0, errorhandler))
-		scriptError("error running function 'on_rightclick': %s\n", lua_tostring(L, -1));
+		scriptError();
+	lua_remove(L, object); // Remove object
+	lua_remove(L, errorhandler); // Remove error handler
 }
 

src/script/cpp_api/s_inventory.cpp

@@ -33,6 +33,9 @@ int ScriptApiDetached::detached_inventory_AllowMove(
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Push callback function on stack
 	if(!getDetachedInventoryCallback(name, "allow_move"))
 		return count;
@@ -42,23 +45,19 @@ int ScriptApiDetached::detached_inventory_AllowMove(
 	InventoryLocation loc;
 	loc.setDetached(name);
 	InvRef::create(L, loc);
-	// from_list
+	lua_pushstring(L, from_list.c_str()); // from_list
-	lua_pushstring(L, from_list.c_str());
+	lua_pushinteger(L, from_index + 1);   // from_index
-	// from_index
+	lua_pushstring(L, to_list.c_str());   // to_list
-	lua_pushinteger(L, from_index + 1);
+	lua_pushinteger(L, to_index + 1);     // to_index
-	// to_list
+	lua_pushinteger(L, count);            // count
-	lua_pushstring(L, to_list.c_str());
+	objectrefGetOrCreate(player);         // player
-	// to_index
+	if(lua_pcall(L, 7, 1, errorhandler))
-	lua_pushinteger(L, to_index + 1);
+		scriptError();
-	// count
-	lua_pushinteger(L, count);
-	// player
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 7, 1, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 	if(!lua_isnumber(L, -1))
 		throw LuaError(L, "allow_move should return a number");
-	return luaL_checkinteger(L, -1);
+	int ret = luaL_checkinteger(L, -1);
+	lua_pop(L, 2); // Pop integer and error handler
+	return ret;
 }
 
 // Return number of accepted items to be put
@@ -69,28 +68,28 @@ int ScriptApiDetached::detached_inventory_AllowPut(
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Push callback function on stack
 	if(!getDetachedInventoryCallback(name, "allow_put"))
 		return stack.count; // All will be accepted
 
 	// Call function(inv, listname, index, stack, player)
-	// inv
 	InventoryLocation loc;
 	loc.setDetached(name);
-	InvRef::create(L, loc);
+	InvRef::create(L, loc);              // inv
-	// listname
+	lua_pushstring(L, listname.c_str()); // listname
-	lua_pushstring(L, listname.c_str());
+	lua_pushinteger(L, index + 1);       // index
-	// index
+	LuaItemStack::create(L, stack);      // stack
-	lua_pushinteger(L, index + 1);
+	objectrefGetOrCreate(player);        // player
-	// stack
+	if(lua_pcall(L, 5, 1, errorhandler))
-	LuaItemStack::create(L, stack);
+		scriptError();
-	// player
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 5, 1, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 	if(!lua_isnumber(L, -1))
 		throw LuaError(L, "allow_put should return a number");
-	return luaL_checkinteger(L, -1);
+	int ret = luaL_checkinteger(L, -1);
+	lua_pop(L, 2); // Pop integer and error handler
+	return ret;
 }
 
 // Return number of accepted items to be taken
@@ -101,28 +100,28 @@ int ScriptApiDetached::detached_inventory_AllowTake(
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Push callback function on stack
 	if(!getDetachedInventoryCallback(name, "allow_take"))
 		return stack.count; // All will be accepted
 
 	// Call function(inv, listname, index, stack, player)
-	// inv
 	InventoryLocation loc;
 	loc.setDetached(name);
-	InvRef::create(L, loc);
+	InvRef::create(L, loc);              // inv
-	// listname
+	lua_pushstring(L, listname.c_str()); // listname
-	lua_pushstring(L, listname.c_str());
+	lua_pushinteger(L, index + 1);       // index
-	// index
+	LuaItemStack::create(L, stack);      // stack
-	lua_pushinteger(L, index + 1);
+	objectrefGetOrCreate(player);        // player
-	// stack
+	if(lua_pcall(L, 5, 1, errorhandler))
-	LuaItemStack::create(L, stack);
+		scriptError();
-	// player
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 5, 1, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 	if(!lua_isnumber(L, -1))
 		throw LuaError(L, "allow_take should return a number");
-	return luaL_checkinteger(L, -1);
+	int ret = luaL_checkinteger(L, -1);
+	lua_pop(L, 2); // Pop integer and error handler
+	return ret;
 }
 
 // Report moved items
@@ -134,6 +133,9 @@ void ScriptApiDetached::detached_inventory_OnMove(
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Push callback function on stack
 	if(!getDetachedInventoryCallback(name, "on_move"))
 		return;
@@ -143,20 +145,15 @@ void ScriptApiDetached::detached_inventory_OnMove(
 	InventoryLocation loc;
 	loc.setDetached(name);
 	InvRef::create(L, loc);
-	// from_list
+	lua_pushstring(L, from_list.c_str()); // from_list
-	lua_pushstring(L, from_list.c_str());
+	lua_pushinteger(L, from_index + 1);   // from_index
-	// from_index
+	lua_pushstring(L, to_list.c_str());   // to_list
-	lua_pushinteger(L, from_index + 1);
+	lua_pushinteger(L, to_index + 1);     // to_index
-	// to_list
+	lua_pushinteger(L, count);            // count
-	lua_pushstring(L, to_list.c_str());
+	objectrefGetOrCreate(player);         // player
-	// to_index
+	if(lua_pcall(L, 7, 0, errorhandler))
-	lua_pushinteger(L, to_index + 1);
+		scriptError();
-	// count
+	lua_pop(L, 1); // Pop error handler
-	lua_pushinteger(L, count);
-	// player
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 7, 0, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 }
 
 // Report put items
@@ -167,6 +164,9 @@ void ScriptApiDetached::detached_inventory_OnPut(
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Push callback function on stack
 	if(!getDetachedInventoryCallback(name, "on_put"))
 		return;
@@ -176,16 +176,13 @@ void ScriptApiDetached::detached_inventory_OnPut(
 	InventoryLocation loc;
 	loc.setDetached(name);
 	InvRef::create(L, loc);
-	// listname
+	lua_pushstring(L, listname.c_str()); // listname
-	lua_pushstring(L, listname.c_str());
+	lua_pushinteger(L, index + 1);       // index
-	// index
+	LuaItemStack::create(L, stack);      // stack
-	lua_pushinteger(L, index + 1);
+	objectrefGetOrCreate(player);        // player
-	// stack
+	if(lua_pcall(L, 5, 0, errorhandler))
-	LuaItemStack::create(L, stack);
+		scriptError();
-	// player
+	lua_pop(L, 1); // Pop error handler
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 5, 0, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 }
 
 // Report taken items
@@ -196,6 +193,9 @@ void ScriptApiDetached::detached_inventory_OnTake(
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Push callback function on stack
 	if(!getDetachedInventoryCallback(name, "on_take"))
 		return;
@@ -205,16 +205,13 @@ void ScriptApiDetached::detached_inventory_OnTake(
 	InventoryLocation loc;
 	loc.setDetached(name);
 	InvRef::create(L, loc);
-	// listname
+	lua_pushstring(L, listname.c_str()); // listname
-	lua_pushstring(L, listname.c_str());
+	lua_pushinteger(L, index + 1);       // index
-	// index
+	LuaItemStack::create(L, stack);      // stack
-	lua_pushinteger(L, index + 1);
+	objectrefGetOrCreate(player);        // player
-	// stack
+	if(lua_pcall(L, 5, 0, errorhandler))
-	LuaItemStack::create(L, stack);
+		scriptError();
-	// player
+	lua_pop(L, 1); // Pop error handler
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 5, 0, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 }
 
 // Retrieves minetest.detached_inventories[name][callbackname]

src/script/cpp_api/s_item.cpp

@@ -34,6 +34,9 @@ bool ScriptApiItem::item_OnDrop(ItemStack &item,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Push callback function on stack
 	if(!getItemCallback(item.name.c_str(), "on_drop"))
 		return false;
@@ -42,10 +45,11 @@ bool ScriptApiItem::item_OnDrop(ItemStack &item,
 	LuaItemStack::create(L, item);
 	objectrefGetOrCreate(dropper);
 	pushFloatPos(L, pos);
-	if(lua_pcall(L, 3, 1, 0))
+	if(lua_pcall(L, 3, 1, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
 	if(!lua_isnil(L, -1))
 		item = read_item(L,-1, getServer());
+	lua_pop(L, 2);  // Pop item and error handler
 	return true;
 }
 
@@ -54,6 +58,9 @@ bool ScriptApiItem::item_OnPlace(ItemStack &item,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Push callback function on stack
 	if(!getItemCallback(item.name.c_str(), "on_place"))
 		return false;
@@ -62,10 +69,11 @@ bool ScriptApiItem::item_OnPlace(ItemStack &item,
 	LuaItemStack::create(L, item);
 	objectrefGetOrCreate(placer);
 	pushPointedThing(pointed);
-	if(lua_pcall(L, 3, 1, 0))
+	if(lua_pcall(L, 3, 1, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
 	if(!lua_isnil(L, -1))
 		item = read_item(L,-1, getServer());
+	lua_pop(L, 2);  // Pop item and error handler
 	return true;
 }
 
@@ -74,6 +82,9 @@ bool ScriptApiItem::item_OnUse(ItemStack &item,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Push callback function on stack
 	if(!getItemCallback(item.name.c_str(), "on_use"))
 		return false;
@@ -82,10 +93,11 @@ bool ScriptApiItem::item_OnUse(ItemStack &item,
 	LuaItemStack::create(L, item);
 	objectrefGetOrCreate(user);
 	pushPointedThing(pointed);
-	if(lua_pcall(L, 3, 1, 0))
+	if(lua_pcall(L, 3, 1, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
 	if(!lua_isnil(L, -1))
 		item = read_item(L,-1, getServer());
+	lua_pop(L, 2);  // Pop item and error handler
 	return true;
 }
 
@@ -94,6 +106,9 @@ bool ScriptApiItem::item_OnCraft(ItemStack &item, ServerActiveObject *user,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	lua_getglobal(L, "minetest");
 	lua_getfield(L, -1, "on_craft");
 	LuaItemStack::create(L, item);
@@ -106,10 +121,11 @@ bool ScriptApiItem::item_OnCraft(ItemStack &item, ServerActiveObject *user,
 	push_items(L, items);
 
 	InvRef::create(L, craft_inv);
-	if(lua_pcall(L, 4, 1, 0))
+	if(lua_pcall(L, 4, 1, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
 	if(!lua_isnil(L, -1))
 		item = read_item(L,-1, getServer());
+	lua_pop(L, 2);  // Pop item and error handler
 	return true;
 }
 
@@ -118,6 +134,9 @@ bool ScriptApiItem::item_CraftPredict(ItemStack &item, ServerActiveObject *user,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	lua_getglobal(L, "minetest");
 	lua_getfield(L, -1, "craft_predict");
 	LuaItemStack::create(L, item);
@@ -130,10 +149,11 @@ bool ScriptApiItem::item_CraftPredict(ItemStack &item, ServerActiveObject *user,
 	push_items(L, items);
 
 	InvRef::create(L, craft_inv);
-	if(lua_pcall(L, 4, 1, 0))
+	if(lua_pcall(L, 4, 1, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
 	if(!lua_isnil(L, -1))
 		item = read_item(L,-1, getServer());
+	lua_pop(L, 2);  // Pop item and error handler
 	return true;
 }
 
@@ -149,10 +169,10 @@ bool ScriptApiItem::getItemCallback(const char *name, const char *callbackname)
 
 	lua_getglobal(L, "minetest");
 	lua_getfield(L, -1, "registered_items");
-	lua_remove(L, -2);
+	lua_remove(L, -2); // Remove minetest
 	luaL_checktype(L, -1, LUA_TTABLE);
 	lua_getfield(L, -1, name);
-	lua_remove(L, -2);
+	lua_remove(L, -2); // Remove registered_items
 	// Should be a table
 	if(lua_type(L, -1) != LUA_TTABLE)
 	{
@@ -167,25 +187,17 @@ bool ScriptApiItem::getItemCallback(const char *name, const char *callbackname)
 		luaL_checktype(L, -1, LUA_TTABLE);
 	}
 	lua_getfield(L, -1, callbackname);
-	lua_remove(L, -2);
+	lua_remove(L, -2); // Remove item def
 	// Should be a function or nil
-	if(lua_type(L, -1) == LUA_TFUNCTION)
+	if (lua_type(L, -1) == LUA_TFUNCTION) {
-	{
 		return true;
-	}
+	} else if (!lua_isnil(L, -1)) {
-	else if(lua_isnil(L, -1))
-	{
-		lua_pop(L, 1);
-		return false;
-	}
-	else
-	{
 		errorstream << "Item \"" << name << "\" callback \""
-			<<callbackname<<" is not a function"<<std::endl;
+			<< callbackname << "\" is not a function" << std::endl;
+	}
 	lua_pop(L, 1);
 	return false;
 }
-}
 
 void ScriptApiItem::pushPointedThing(const PointedThing& pointed)
 {

src/script/cpp_api/s_mainmenu.cpp

@@ -37,29 +37,41 @@ void ScriptApiMainMenu::handleMainMenuEvent(std::string text)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Get handler function
 	lua_getglobal(L, "engine");
 	lua_getfield(L, -1, "event_handler");
-	if(lua_isnil(L, -1))
+	lua_remove(L, -2); // Remove engine
+	if(lua_isnil(L, -1)) {
+		lua_pop(L, 1); // Pop event_handler
 		return;
+	}
 	luaL_checktype(L, -1, LUA_TFUNCTION);
 
 	// Call it
 	lua_pushstring(L, text.c_str());
-	if(lua_pcall(L, 1, 0, 0))
+	if(lua_pcall(L, 1, 0, errorhandler))
-		scriptError("error running function engine.event_handler: %s\n",
+		scriptError();
-				lua_tostring(L, -1));
+	lua_pop(L, 1); // Pop error handler
 }
 
 void ScriptApiMainMenu::handleMainMenuButtons(std::map<std::string, std::string> fields)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Get handler function
 	lua_getglobal(L, "engine");
 	lua_getfield(L, -1, "button_handler");
-	if(lua_isnil(L, -1))
+	lua_remove(L, -2); // Remove engine
+	if(lua_isnil(L, -1)) {
+		lua_pop(L, 1); // Pop button handler
 		return;
+	}
 	luaL_checktype(L, -1, LUA_TFUNCTION);
 
 	// Convert fields to lua table
@@ -74,7 +86,7 @@ void ScriptApiMainMenu::handleMainMenuButtons(std::map<std::string, std::string>
 	}
 
 	// Call it
-	if(lua_pcall(L, 1, 0, 0))
+	if(lua_pcall(L, 1, 0, errorhandler))
-		scriptError("error running function engine.button_handler: %s\n",
+		scriptError();
-				lua_tostring(L, -1));
+	lua_pop(L, 1); // Pop error handler
 }

src/script/cpp_api/s_node.cpp

@@ -91,6 +91,9 @@ bool ScriptApiNode::node_on_punch(v3s16 p, MapNode node,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// Push callback function on stack
@@ -101,8 +104,9 @@ bool ScriptApiNode::node_on_punch(v3s16 p, MapNode node,
 	push_v3s16(L, p);
 	pushnode(L, node, ndef);
 	objectrefGetOrCreate(puncher);
-	if(lua_pcall(L, 3, 0, 0))
+	if(lua_pcall(L, 3, 0, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
+	lua_pop(L, 1); // Pop error handler
 	return true;
 }
 
@@ -111,6 +115,9 @@ bool ScriptApiNode::node_on_dig(v3s16 p, MapNode node,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// Push callback function on stack
@@ -121,8 +128,9 @@ bool ScriptApiNode::node_on_dig(v3s16 p, MapNode node,
 	push_v3s16(L, p);
 	pushnode(L, node, ndef);
 	objectrefGetOrCreate(digger);
-	if(lua_pcall(L, 3, 0, 0))
+	if(lua_pcall(L, 3, 0, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
+	lua_pop(L, 1); // Pop error handler
 	return true;
 }
 
@@ -130,6 +138,9 @@ void ScriptApiNode::node_on_construct(v3s16 p, MapNode node)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// Push callback function on stack
@@ -138,14 +149,18 @@ void ScriptApiNode::node_on_construct(v3s16 p, MapNode node)
 
 	// Call function
 	push_v3s16(L, p);
-	if(lua_pcall(L, 1, 0, 0))
+	if(lua_pcall(L, 1, 0, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
+	lua_pop(L, 1); // Pop error handler
 }
 
 void ScriptApiNode::node_on_destruct(v3s16 p, MapNode node)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// Push callback function on stack
@@ -154,14 +169,18 @@ void ScriptApiNode::node_on_destruct(v3s16 p, MapNode node)
 
 	// Call function
 	push_v3s16(L, p);
-	if(lua_pcall(L, 1, 0, 0))
+	if(lua_pcall(L, 1, 0, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
+	lua_pop(L, 1); // Pop error handler
 }
 
 void ScriptApiNode::node_after_destruct(v3s16 p, MapNode node)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// Push callback function on stack
@@ -171,14 +190,18 @@ void ScriptApiNode::node_after_destruct(v3s16 p, MapNode node)
 	// Call function
 	push_v3s16(L, p);
 	pushnode(L, node, ndef);
-	if(lua_pcall(L, 2, 0, 0))
+	if(lua_pcall(L, 2, 0, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
+	lua_pop(L, 1); // Pop error handler
 }
 
 bool ScriptApiNode::node_on_timer(v3s16 p, MapNode node, f32 dtime)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// Push callback function on stack
@@ -188,12 +211,10 @@ bool ScriptApiNode::node_on_timer(v3s16 p, MapNode node, f32 dtime)
 	// Call function
 	push_v3s16(L, p);
 	lua_pushnumber(L,dtime);
-	if(lua_pcall(L, 2, 1, 0))
+	if(lua_pcall(L, 2, 1, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
-	if((bool)lua_isboolean(L,-1) && (bool)lua_toboolean(L,-1) == true)
+	lua_remove(L, errorhandler); // Remove error handler
-		return true;
+	return (bool) lua_isboolean(L, -1) && (bool) lua_toboolean(L, -1) == true;
-
-	return false;
 }
 
 void ScriptApiNode::node_on_receive_fields(v3s16 p,
@@ -203,6 +224,9 @@ void ScriptApiNode::node_on_receive_fields(v3s16 p,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// If node doesn't exist, we don't know what callback to call
@@ -215,12 +239,9 @@ void ScriptApiNode::node_on_receive_fields(v3s16 p,
 		return;
 
 	// Call function
-	// param 1
+	push_v3s16(L, p);                    // pos
-	push_v3s16(L, p);
+	lua_pushstring(L, formname.c_str()); // formname
-	// param 2
+	lua_newtable(L);                     // fields
-	lua_pushstring(L, formname.c_str());
-	// param 3
-	lua_newtable(L);
 	for(std::map<std::string, std::string>::const_iterator
 			i = fields.begin(); i != fields.end(); i++){
 		const std::string &name = i->first;
@@ -229,26 +250,37 @@ void ScriptApiNode::node_on_receive_fields(v3s16 p,
 		lua_pushlstring(L, value.c_str(), value.size());
 		lua_settable(L, -3);
 	}
-	// param 4
+	objectrefGetOrCreate(sender);        // player
-	objectrefGetOrCreate(sender);
+	if(lua_pcall(L, 4, 0, errorhandler))
-	if(lua_pcall(L, 4, 0, 0))
+		scriptError();
-		scriptError("error: %s", lua_tostring(L, -1));
+	lua_pop(L, 1); // Pop error handler
 }
 
 void ScriptApiNode::node_falling_update(v3s16 p)
 {
 	SCRIPTAPI_PRECHECKHEADER
+
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	lua_getglobal(L, "nodeupdate");
 	push_v3s16(L, p);
-	if(lua_pcall(L, 1, 0, 0))
+	if(lua_pcall(L, 1, 0, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
+	lua_pop(L, 1); // Pop error handler
 }
 
 void ScriptApiNode::node_falling_update_single(v3s16 p)
 {
 	SCRIPTAPI_PRECHECKHEADER
+
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	lua_getglobal(L, "nodeupdate_single");
 	push_v3s16(L, p);
-	if(lua_pcall(L, 1, 0, 0))
+	if(lua_pcall(L, 1, 0, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
+	lua_pop(L, 1); // Pop error handler
 }
+

src/script/cpp_api/s_nodemeta.cpp

@@ -34,6 +34,9 @@ int ScriptApiNodemeta::nodemeta_inventory_AllowMove(v3s16 p,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// If node doesn't exist, we don't know what callback to call
@@ -47,25 +50,21 @@ int ScriptApiNodemeta::nodemeta_inventory_AllowMove(v3s16 p,
 		return count;
 
 	// function(pos, from_list, from_index, to_list, to_index, count, player)
-	// pos
+	push_v3s16(L, p);                     // pos
-	push_v3s16(L, p);
+	lua_pushstring(L, from_list.c_str()); // from_list
-	// from_list
+	lua_pushinteger(L, from_index + 1);   // from_index
-	lua_pushstring(L, from_list.c_str());
+	lua_pushstring(L, to_list.c_str());   // to_list
-	// from_index
+	lua_pushinteger(L, to_index + 1);     // to_index
-	lua_pushinteger(L, from_index + 1);
+	lua_pushinteger(L, count);            // count
-	// to_list
+	objectrefGetOrCreate(player);         // player
-	lua_pushstring(L, to_list.c_str());
+	if(lua_pcall(L, 7, 1, errorhandler))
-	// to_index
+		scriptError();
-	lua_pushinteger(L, to_index + 1);
+	lua_remove(L, errorhandler); // Remove error handler
-	// count
-	lua_pushinteger(L, count);
-	// player
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 7, 1, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 	if(!lua_isnumber(L, -1))
 		throw LuaError(L, "allow_metadata_inventory_move should return a number");
-	return luaL_checkinteger(L, -1);
+	int num = luaL_checkinteger(L, -1);
+	lua_pop(L, 1); // Pop integer
+	return num;
 }
 
 // Return number of accepted items to be put
@@ -75,6 +74,9 @@ int ScriptApiNodemeta::nodemeta_inventory_AllowPut(v3s16 p,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// If node doesn't exist, we don't know what callback to call
@@ -88,21 +90,19 @@ int ScriptApiNodemeta::nodemeta_inventory_AllowPut(v3s16 p,
 		return stack.count;
 
 	// Call function(pos, listname, index, stack, player)
-	// pos
+	push_v3s16(L, p);                    // pos
-	push_v3s16(L, p);
+	lua_pushstring(L, listname.c_str()); // listname
-	// listname
+	lua_pushinteger(L, index + 1);       // index
-	lua_pushstring(L, listname.c_str());
+	LuaItemStack::create(L, stack);      // stack
-	// index
+	objectrefGetOrCreate(player);        // player
-	lua_pushinteger(L, index + 1);
+	if(lua_pcall(L, 5, 1, errorhandler))
-	// stack
+		scriptError();
-	LuaItemStack::create(L, stack);
+	lua_remove(L, errorhandler); // Remove error handler
-	// player
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 5, 1, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 	if(!lua_isnumber(L, -1))
 		throw LuaError(L, "allow_metadata_inventory_put should return a number");
-	return luaL_checkinteger(L, -1);
+	int num = luaL_checkinteger(L, -1);
+	lua_pop(L, 1); // Pop integer
+	return num;
 }
 
 // Return number of accepted items to be taken
@@ -112,6 +112,9 @@ int ScriptApiNodemeta::nodemeta_inventory_AllowTake(v3s16 p,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// If node doesn't exist, we don't know what callback to call
@@ -125,21 +128,19 @@ int ScriptApiNodemeta::nodemeta_inventory_AllowTake(v3s16 p,
 		return stack.count;
 
 	// Call function(pos, listname, index, count, player)
-	// pos
+	push_v3s16(L, p);                    // pos
-	push_v3s16(L, p);
+	lua_pushstring(L, listname.c_str()); // listname
-	// listname
+	lua_pushinteger(L, index + 1);       // index
-	lua_pushstring(L, listname.c_str());
+	LuaItemStack::create(L, stack);      // stack
-	// index
+	objectrefGetOrCreate(player);        // player
-	lua_pushinteger(L, index + 1);
+	if(lua_pcall(L, 5, 1, errorhandler))
-	// stack
+		scriptError();
-	LuaItemStack::create(L, stack);
+	lua_remove(L, errorhandler); // Remove error handler
-	// player
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 5, 1, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 	if(!lua_isnumber(L, -1))
 		throw LuaError(L, "allow_metadata_inventory_take should return a number");
-	return luaL_checkinteger(L, -1);
+	int num = luaL_checkinteger(L, -1);
+	lua_pop(L, 1); // Pop integer
+	return num;
 }
 
 // Report moved items
@@ -150,6 +151,9 @@ void ScriptApiNodemeta::nodemeta_inventory_OnMove(v3s16 p,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// If node doesn't exist, we don't know what callback to call
@@ -163,22 +167,16 @@ void ScriptApiNodemeta::nodemeta_inventory_OnMove(v3s16 p,
 		return;
 
 	// function(pos, from_list, from_index, to_list, to_index, count, player)
-	// pos
+	push_v3s16(L, p);                     // pos
-	push_v3s16(L, p);
+	lua_pushstring(L, from_list.c_str()); // from_list
-	// from_list
+	lua_pushinteger(L, from_index + 1);   // from_index
-	lua_pushstring(L, from_list.c_str());
+	lua_pushstring(L, to_list.c_str());   // to_list
-	// from_index
+	lua_pushinteger(L, to_index + 1);     // to_index
-	lua_pushinteger(L, from_index + 1);
+	lua_pushinteger(L, count);            // count
-	// to_list
+	objectrefGetOrCreate(player);         // player
-	lua_pushstring(L, to_list.c_str());
+	if(lua_pcall(L, 7, 0, errorhandler))
-	// to_index
+		scriptError();
-	lua_pushinteger(L, to_index + 1);
+	lua_pop(L, 1); // Pop error handler
-	// count
-	lua_pushinteger(L, count);
-	// player
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 7, 0, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 }
 
 // Report put items
@@ -188,6 +186,9 @@ void ScriptApiNodemeta::nodemeta_inventory_OnPut(v3s16 p,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// If node doesn't exist, we don't know what callback to call
@@ -201,18 +202,14 @@ void ScriptApiNodemeta::nodemeta_inventory_OnPut(v3s16 p,
 		return;
 
 	// Call function(pos, listname, index, stack, player)
-	// pos
+	push_v3s16(L, p);                    // pos
-	push_v3s16(L, p);
+	lua_pushstring(L, listname.c_str()); // listname
-	// listname
+	lua_pushinteger(L, index + 1);       // index
-	lua_pushstring(L, listname.c_str());
+	LuaItemStack::create(L, stack);      // stack
-	// index
+	objectrefGetOrCreate(player);        // player
-	lua_pushinteger(L, index + 1);
+	if(lua_pcall(L, 5, 0, errorhandler))
-	// stack
+		scriptError();
-	LuaItemStack::create(L, stack);
+	lua_pop(L, 1); // Pop error handler
-	// player
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 5, 0, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 }
 
 // Report taken items
@@ -222,6 +219,9 @@ void ScriptApiNodemeta::nodemeta_inventory_OnTake(v3s16 p,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	INodeDefManager *ndef = getServer()->ndef();
 
 	// If node doesn't exist, we don't know what callback to call
@@ -235,18 +235,14 @@ void ScriptApiNodemeta::nodemeta_inventory_OnTake(v3s16 p,
 		return;
 
 	// Call function(pos, listname, index, stack, player)
-	// pos
+	push_v3s16(L, p);                    // pos
-	push_v3s16(L, p);
+	lua_pushstring(L, listname.c_str()); // listname
-	// listname
+	lua_pushinteger(L, index + 1);       // index
-	lua_pushstring(L, listname.c_str());
+	LuaItemStack::create(L, stack);      // stack
-	// index
+	objectrefGetOrCreate(player);        // player
-	lua_pushinteger(L, index + 1);
+	if(lua_pcall(L, 5, 0, errorhandler))
-	// stack
+		scriptError();
-	LuaItemStack::create(L, stack);
+	lua_pop(L, 1); // Pop error handler
-	// player
-	objectrefGetOrCreate(player);
-	if(lua_pcall(L, 5, 0, 0))
-		scriptError("error: %s", lua_tostring(L, -1));
 }
 
 ScriptApiNodemeta::ScriptApiNodemeta() {

src/script/cpp_api/s_server.cpp

@@ -27,13 +27,18 @@ bool ScriptApiServer::getAuth(const std::string &playername,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	getAuthHandler();
 	lua_getfield(L, -1, "get_auth");
 	if(lua_type(L, -1) != LUA_TFUNCTION)
 		throw LuaError(L, "Authentication handler missing get_auth");
 	lua_pushstring(L, playername.c_str());
-	if(lua_pcall(L, 1, 1, 0))
+	if(lua_pcall(L, 1, 1, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
+	lua_remove(L, -2); // Remove auth handler
+	lua_remove(L, errorhandler); // Remove error handler
 
 	// nil = login not allowed
 	if(lua_isnil(L, -1))
@@ -49,8 +54,7 @@ bool ScriptApiServer::getAuth(const std::string &playername,
 
 	lua_getfield(L, -1, "privileges");
 	if(!lua_istable(L, -1))
-		throw LuaError(L,
+		throw LuaError(L, "Authentication handler didn't return privilege table");
-				"Authentication handler didn't return privilege table");
 	if(dst_privs)
 		readPrivileges(-1, *dst_privs);
 	lua_pop(L, 1);
@@ -68,6 +72,7 @@ void ScriptApiServer::getAuthHandler()
 		lua_pop(L, 1);
 		lua_getfield(L, -1, "builtin_auth_handler");
 	}
+	lua_remove(L, -2); // Remove minetest
 	if(lua_type(L, -1) != LUA_TTABLE)
 		throw LuaError(L, "Authentication handler table not valid");
 }
@@ -96,14 +101,19 @@ void ScriptApiServer::createAuth(const std::string &playername,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	getAuthHandler();
 	lua_getfield(L, -1, "create_auth");
+	lua_remove(L, -2); // Remove auth handler
 	if(lua_type(L, -1) != LUA_TFUNCTION)
 		throw LuaError(L, "Authentication handler missing create_auth");
 	lua_pushstring(L, playername.c_str());
 	lua_pushstring(L, password.c_str());
-	if(lua_pcall(L, 2, 0, 0))
+	if(lua_pcall(L, 2, 0, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
+	lua_pop(L, 1); // Pop error handler
 }
 
 bool ScriptApiServer::setPassword(const std::string &playername,
@@ -111,14 +121,19 @@ bool ScriptApiServer::setPassword(const std::string &playername,
 {
 	SCRIPTAPI_PRECHECKHEADER
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	getAuthHandler();
 	lua_getfield(L, -1, "set_password");
+	lua_remove(L, -2); // Remove auth handler
 	if(lua_type(L, -1) != LUA_TFUNCTION)
 		throw LuaError(L, "Authentication handler missing set_password");
 	lua_pushstring(L, playername.c_str());
 	lua_pushstring(L, password.c_str());
-	if(lua_pcall(L, 2, 1, 0))
+	if(lua_pcall(L, 2, 1, errorhandler))
-		scriptError("error: %s", lua_tostring(L, -1));
+		scriptError();
+	lua_remove(L, -2); // Remove error handler
 	return lua_toboolean(L, -1);
 }
 

src/script/lua_api/l_base.h

@@ -21,6 +21,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #define L_BASE_H_
 
 #include "common/c_types.h"
+#include "common/c_internal.h"
 
 extern "C" {
 #include <lua.h>

src/script/lua_api/l_craft.cpp

@@ -449,7 +449,7 @@ int ModApiCraft::l_get_all_craft_recipes(lua_State *L)
 			lua_pushstring(L, &tmpout.item[0]);
 			lua_setfield(L, -2, "output");
 			if (lua_pcall(L, 2, 0, 0))
-				script_error(L, "error: %s", lua_tostring(L, -1));
+				script_error(L);
 		}
 	}
 	return 1;

src/script/lua_api/l_env.cpp

@@ -53,28 +53,34 @@ void LuaABM::trigger(ServerEnvironment *env, v3s16 p, MapNode n,
 	assert(lua_checkstack(L, 20));
 	StackUnroller stack_unroller(L);
 
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Get minetest.registered_abms
 	lua_getglobal(L, "minetest");
 	lua_getfield(L, -1, "registered_abms");
 	luaL_checktype(L, -1, LUA_TTABLE);
-	int registered_abms = lua_gettop(L);
+	lua_remove(L, -2); // Remove "minetest"
 
 	// Get minetest.registered_abms[m_id]
 	lua_pushnumber(L, m_id);
-	lua_gettable(L, registered_abms);
+	lua_gettable(L, -2);
 	if(lua_isnil(L, -1))
 		assert(0);
+	lua_remove(L, -2); // Remove "registered_abms"
 
 	// Call action
 	luaL_checktype(L, -1, LUA_TTABLE);
 	lua_getfield(L, -1, "action");
 	luaL_checktype(L, -1, LUA_TFUNCTION);
+	lua_remove(L, -2); // Remove "registered_abms[m_id]"
 	push_v3s16(L, p);
 	pushnode(L, n, env->getGameDef()->ndef());
 	lua_pushnumber(L, active_object_count);
 	lua_pushnumber(L, active_object_count_wider);
-	if(lua_pcall(L, 4, 0, 0))
+	if(lua_pcall(L, 4, 0, errorhandler))
-		script_error(L, "error: %s", lua_tostring(L, -1));
+		script_error(L);
+	lua_pop(L, 1); // Pop error handler
 }
 
 // Exported functions
@@ -370,15 +376,21 @@ int ModApiEnvMod::l_add_item(lua_State *L)
 	ItemStack item = read_item(L, 2,getServer(L));
 	if(item.empty() || !item.isKnown(getServer(L)->idef()))
 		return 0;
+
+	lua_pushcfunction(L, script_error_handler);
+	int errorhandler = lua_gettop(L);
+
 	// Use minetest.spawn_item to spawn a __builtin:item
 	lua_getglobal(L, "minetest");
 	lua_getfield(L, -1, "spawn_item");
+	lua_remove(L, -2); // Remove minetest
 	if(lua_isnil(L, -1))
 		return 0;
 	lua_pushvalue(L, 1);
 	lua_pushstring(L, item.getItemString().c_str());
-	if(lua_pcall(L, 2, 1, 0))
+	if(lua_pcall(L, 2, 1, errorhandler))
-		script_error(L, "error: %s", lua_tostring(L, -1));
+		script_error(L);
+	lua_remove(L, errorhandler); // Remove error handler
 	return 1;
 	/*lua_pushvalue(L, 1);
 	lua_pushstring(L, "__builtin:item");
@@ -441,7 +453,7 @@ int ModApiEnvMod::l_get_objects_inside_radius(lua_State *L)
 		lua_pushvalue(L, table);
 		getScriptApiBase(L)->objectrefGetOrCreate(obj);
 		if(lua_pcall(L, 2, 0, 0))
-			script_error(L, "error: %s", lua_tostring(L, -1));
+			script_error(L);
 	}
 	return 1;
 }
@@ -569,7 +581,7 @@ int ModApiEnvMod::l_find_nodes_in_area(lua_State *L)
 			lua_pushvalue(L, table);
 			push_v3s16(L, p);
 			if(lua_pcall(L, 2, 0, 0))
-				script_error(L, "error: %s", lua_tostring(L, -1));
+				script_error(L);
 		}
 	}
 	return 1;

src/script/lua_api/l_noise.cpp

@@ -333,7 +333,10 @@ int LuaPseudoRandom::l_next(lua_State *L)
 		throw LuaError(L, "PseudoRandom.next(): max < min");
 	}
 	if(max - min != 32767 && max - min > 32767/5)
-		throw LuaError(L, "PseudoRandom.next() max-min is not 32767 and is > 32768/5. This is disallowed due to the bad random distribution the implementation would otherwise make.");
+		throw LuaError(L, "PseudoRandom.next() max-min is not 32767"
+				" and is > 32768/5. This is disallowed due to"
+				" the bad random distribution the"
+				" implementation would otherwise make.");
 	PseudoRandom &pseudo = o->m_pseudo;
 	int val = pseudo.next();
 	val = (val % (max-min+1)) + min;

src/script/lua_api/l_rollback.cpp

@@ -66,7 +66,7 @@ int ModApiRollback::l_rollback_revert_actions_by(lua_State *L)
 		lua_pushvalue(L, table);
 		lua_pushstring(L, i->c_str());
 		if(lua_pcall(L, 2, 0, 0))
-			script_error(L, "error: %s", lua_tostring(L, -1));
+			script_error(L);
 	}
 	lua_remove(L, -2); // Remove table
 	lua_remove(L, -2); // Remove insert

src/script/lua_api/l_server.cpp

@@ -220,6 +220,7 @@ int ModApiServer::l_get_modpath(lua_State *L)
 int ModApiServer::l_get_modnames(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;
+
 	// Get a list of mods
 	std::list<std::string> mods_unsorted, mods_sorted;
 	getServer(L)->getModNames(mods_unsorted);
@@ -263,7 +264,7 @@ int ModApiServer::l_get_modnames(lua_State *L)
 		lua_pushstring(L, (*i).c_str());
 		if(lua_pcall(L, 2, 0, 0) != 0)
 		{
-			script_error(L, "error: %s", lua_tostring(L, -1));
+			script_error(L);
 		}
 		++i;
 	}