add lua_function in side filters

src/scripting/game_lua_kernel.cpp

@@ -4824,6 +4824,18 @@ bool game_lua_kernel::run_filter(char const *name, const map_location& l)
 	lua_pushinteger(mState, l.wml_y());
 	return run_filter(name, 2);
 }
+
+/**
+* Runs a script from a location filter.
+* The script is an already compiled function given by its name.
+*/
+bool game_lua_kernel::run_filter(char const *name, const team& t)
+{
+	//TODO: instead of passing the lua team object we coudl also jsut pass its 
+	//      number. then we wouldn't need this const cast.
+	luaW_pushteam(mState, const_cast<team&>(t));
+	return run_filter(name, 1);
+}
 /**
 * Runs a script from a unit filter.
 * The script is an already compiled function given by its name.

src/scripting/game_lua_kernel.hpp

@@ -213,6 +213,7 @@ public:
 		const game_events::queued_event&);
 	bool run_filter(char const *name, const unit& u);
 	bool run_filter(char const *name, const map_location& l);
+	bool run_filter(char const *name, const team& t);
 	bool run_filter(char const *name, int nArgs);
 	bool run_wml_conditional(const std::string&, const vconfig&);
 

src/side_filter.cpp

@@ -23,6 +23,7 @@
 #include "variable.hpp"
 #include "team.hpp"
 #include "serialization/string_utils.hpp"
+#include "scripting/game_lua_kernel.hpp"
 #include "play_controller.hpp"
 #include "resources.hpp"
 #include "synced_context.hpp"
@@ -30,6 +31,7 @@
 #include "units/filter.hpp"
 #include "units/map.hpp"
 #include "variable.hpp"
+#include "filter_context.hpp"
 #include "formula/callable_objects.hpp"
 #include "formula/formula.hpp"
 #include "formula/function_gamestate.hpp"
@@ -243,6 +245,16 @@ bool side_filter::match_internal(const team &t) const
 		}
 	}
 
+	if (cfg_.has_attribute("lua_function")) {
+		std::string lua_function = cfg_["lua_function"].str();
+		if (!lua_function.empty() && fc_->get_lua_kernel()) {
+			if (!fc_->get_lua_kernel()->run_filter(lua_function.c_str(), t)) {
+				return false;
+			}
+		}
+	}
+	
+
 	return true;
 }