From 2c154b580df12ee3038a7025d7bf0c3d78c43e21 Mon Sep 17 00:00:00 2001
From: Victor Sergienko <singalen@gmail.com>
Date: Thu, 23 Nov 2017 21:19:28 -0800
Subject: [PATCH] Crash in attack_type::matches_filter - impl_unit_attack_match
 in some scenarios.

---
 src/scripting/lua_unit_attacks.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/scripting/lua_unit_attacks.cpp b/src/scripting/lua_unit_attacks.cpp
index 6740e0b755b..1fc3eec5384 100644
--- a/src/scripting/lua_unit_attacks.cpp
+++ b/src/scripting/lua_unit_attacks.cpp
@@ -319,6 +319,9 @@ static int impl_unit_attack_match(lua_State* L)
 {
 	const_attack_ptr atk = luaW_toweapon(L, 1);
 	config cfg = luaW_checkconfig(L, 2);
+	if(!atk) {
+		return luaL_argerror(L, 1, "invalid attack");
+	}
 	lua_pushboolean(L, atk->matches_filter(cfg));
 	return 1;
 }