add lua function "fire_wml_menu_item" and unit tests for menu items

this commit also changed slightly the way that wml menu events
are synced. previously they were run via "run_in_synced_context",
now they are run via "run_in_synced_context_if_not_already", which
makes it safe to fire them from lua (a synced context).

data/test/scenarios/test_menu_items.cfg

@@ -0,0 +1,118 @@
+#
+# Test if wml menu items are working
+#
+
+{GENERIC_UNIT_TEST "test_wml_menu_items_1" (
+	[event]
+		name = start
+		
+	        [set_menu_item]
+	            id=test1
+	            description="store location"
+	            [command]
+			{VARIABLE mx $x1}
+			{VARIABLE my $y1}
+	            [/command]
+        	[/set_menu_item]
+
+		[lua]
+			code = << wesnoth.fire_wml_menu_item("test1", 3, 3) >>
+		[/lua]
+
+		{ASSERT {VARIABLE_CONDITIONAL mx equals 3}}
+		{ASSERT {VARIABLE_CONDITIONAL my equals 3}}
+		{RETURN ([true][/true])}
+	[/event]
+)}
+
+#
+# This test should be failing although you might think it succeeds.
+# The test asserts that if filter_location for a menu_item is false,
+# it should return false if wesnoth attempts to fire it. However this
+# isn't the case, filter_location is normally checked before the
+# attempt to fire it.
+#
+{GENERIC_UNIT_TEST "test_wml_menu_items_2" (
+	[event]
+		name = start
+		
+	        [set_menu_item]
+	            id=test2
+	            description="spawn a unit"
+		    [filter_location]
+			[not]
+			    [have_unit]
+				x=$x1
+				y=$y1
+			    [/have_unit]
+			[/not]
+		    [/filter_location]
+	            [command]
+			{UNIT 2 "Orcish Grunt" $x1 $y1 ()}
+	            [/command]
+        	[/set_menu_item]
+
+		[lua]
+			code = << r = wesnoth.fire_wml_menu_item("test2", 3, 3)
+				  r = r and not wesnoth.fire_wml_menu_item("test2", 3, 3)
+				  r = r and wesnoth.fire_wml_menu_item("test2", 4, 4)
+				  r = r and not wesnoth.fire_wml_menu_item("test2", 4, 4)
+				  wesnoth.set_variable("result", r) >>
+		[/lua]
+
+		{RETURN {VARIABLE_CONDITIONAL result boolean_equals true}}
+	[/event]
+)}
+
+#
+# An ammended form of the above test, which checks a menu item which creates a unit,
+# being fired twice.
+#
+{GENERIC_UNIT_TEST "test_wml_menu_items_3" (
+	[event]
+		name = start
+
+	        [set_menu_item]
+	            id=test3
+	            description="Summon Troll"
+	            [show_if]
+	                [not]
+	                    [have_unit]
+	                        x,y=$x1,$y1
+	                    [/have_unit]
+	                [/not]
+	            [/show_if]
+	            [filter_location]
+	            [/filter_location]
+	            [command]
+	                {NAMED_LOYAL_UNIT $side_number (Troll) $x1 $y1 (MagicTroll) ("Magic Troll")}
+	                [fire_event]
+	                    name=apply_troll_skin
+	                    [primary_unit]
+	                        x=$x1
+	                        y=$y1
+	                    [/primary_unit]
+	                [/fire_event]
+	            [/command]
+	        [/set_menu_item]
+
+		[lua]
+			code = << r = wesnoth.fire_wml_menu_item("test3", 3, 3) >>
+		[/lua]
+		{ASSERT ([have_unit]
+				x,y = 3,3
+			[/have_unit])}
+
+		[lua]
+			code = << r = r and wesnoth.fire_wml_menu_item("test3", 4, 4) >>
+		[/lua]
+		{ASSERT ([have_unit]
+				x,y = 4,4
+			[/have_unit])}
+
+		[lua]
+			code = << wesnoth.set_variable("result", r) >>
+		[/lua]
+		{RETURN {VARIABLE_CONDITIONAL result boolean_equals true}}
+	[/event]
+)}

src/game_events/menu_item.cpp

@@ -212,7 +212,7 @@ void wml_menu_item::fire_event(const map_location & event_hex, const game_data &
 	}
 	else
 	{
-		synced_context::run_in_synced_context("fire_event",  replay_helper::get_event(event_name_, event_hex, NULL));
+		synced_context::run_in_synced_context_if_not_already("fire_event",  replay_helper::get_event(event_name_, event_hex, NULL));
 	}
 }
 

src/scripting/game_lua_kernel.cpp

@@ -666,6 +666,31 @@ int game_lua_kernel::intf_fire_event(lua_State *L)
 	return 1;
 }
 
+/**
+ * Fires a wml menu item.
+ * - Arg 1: id of the item. it is not possible to fire items that don't have ids with this function.
+ * - Arg 2,3: optional first location.
+ * - Ret 1: boolean, true indicating that the event was fired successfully
+ *
+ * NOTE: This is not an "official" feature, it may currently cause assertion failures if used with
+ * menu items which have "needs_select". It is not supported right now to use it this way.
+ * The purpose of this function right now is to make it possible to have automated sanity tests for
+ * the wml menu items system.
+ */
+int game_lua_kernel::intf_fire_wml_menu_item(lua_State *L)
+{
+	char const *m = luaL_checkstring(L, 1);
+
+	map_location l1;
+
+	l1.x = luaL_checkinteger(L, 2) - 1;
+	l1.y = luaL_checkinteger(L, 3) - 1;
+
+	bool b = gamedata().get_wml_menu_items().fire_item(m, l1, gamedata(), game_state_, units());
+	lua_pushboolean(L, b);
+	return 1;
+}
+
 /**
  * Gets a WML variable.
  * - Arg 1: string containing the variable name.
@@ -3643,6 +3668,7 @@ game_lua_kernel::game_lua_kernel(const config &cfg, CVideo * video, game_state &
 		{ "find_reach",                boost::bind(&game_lua_kernel::intf_find_reach,                this, _1        )},
 		{ "find_vacant_tile",          boost::bind(&game_lua_kernel::intf_find_vacant_tile,          this, _1        )},
 		{ "fire_event",                boost::bind(&game_lua_kernel::intf_fire_event,                this, _1        )},
+		{ "fire_wml_menu_item",        boost::bind(&game_lua_kernel::intf_fire_wml_menu_item,        this, _1        )},
 		{ "float_label",               boost::bind(&game_lua_kernel::intf_float_label,               this, _1        )},
 		{ "gamestate_inspector",       boost::bind(&game_lua_kernel::intf_gamestate_inspector,       this, _1        )},
 		{ "get_all_vars",              boost::bind(&game_lua_kernel::intf_get_all_vars,              this, _1        )},

src/scripting/game_lua_kernel.hpp

@@ -151,6 +151,7 @@ class game_lua_kernel : public lua_kernel_base
 	int impl_theme_items_set(lua_State *L);
 	int cfun_wml_action(lua_State *L);
 	int intf_fire_event(lua_State *L);
+	int intf_fire_wml_menu_item(lua_State *L);
 
 	//private helpers
 	std::string synced_state();

wml_test_schedule

@@ -125,3 +125,9 @@
 0 recruit_facing_enemy_two
 0 recruit_facing_leader
 0 recruit_facing_center
+#
+# Interface tests
+#
+0 test_wml_menu_items_1
+1 test_wml_menu_items_2
+0 test_wml_menu_items_3