tweak(core/five): don't remove skeleton from weapons with components

Unfortunately, the game doesn't ensure skeleton existence in some nasty places. This fix seems to be the easiest and safest workaround.

code/components/gta-core-five/src/PatchWeaponDropSkeleton.cpp

@@ -1,6 +1,8 @@
 #include <StdInc.h>
 #include <Hooking.h>
 
+#include "CrossBuildRuntime.h"
+
 //
 // When the game creates a weapon object for the "CWeapon" instance, it creates a skeleton
 // and has many checks to ensure it exists when necessary. However, when the game needs
@@ -13,30 +15,88 @@ namespace rage
 class fwEntity;
 }
 
-class CObject;
 class CPedWeaponManager;
+class CWeaponComponent;
+
+// TODO: refactor and move to EntitySystem in the future.
+class CWeapon
+{
+public:
+	int GetNumComponents();
+};
+
+class CObject
+{
+public:
+	CWeapon* GetWeapon();
+};
+
+static uint32_t g_objectWeaponPointerOffset;
+static uint32_t g_weaponNumComponentsOffset;
 
 static hook::cdecl_stub<void(rage::fwEntity*)> _deleteEntitySkeleton([]()
 {
 	return hook::get_call(hook::get_pattern("E8 ? ? ? ? 33 D2 48 8B CB E8 ? ? ? ? 81 A3"));
 });
 
+inline CWeapon* CObject::GetWeapon()
+{
+	return *reinterpret_cast<CWeapon**>(reinterpret_cast<char*>(this) + g_objectWeaponPointerOffset);
+}
+
+inline int CWeapon::GetNumComponents()
+{
+	return *reinterpret_cast<int*>(reinterpret_cast<char*>(this) + g_weaponNumComponentsOffset);
+}
+
 static CObject*(*g_origPedWeaponManagerDropWeapon)(CPedWeaponManager*, uint32_t, bool, bool, bool, bool);
 static CObject* PedWeaponManagerDropWeapon(CPedWeaponManager* self, uint32_t weaponHash, bool flag1, bool flag2, bool flag3, bool flag4)
 {
-	auto obj = g_origPedWeaponManagerDropWeapon(self, weaponHash, flag1, flag2, flag3, flag4);
+	auto object = g_origPedWeaponManagerDropWeapon(self, weaponHash, flag1, flag2, flag3, flag4);
 
-	if (obj)
+	if (object)
 	{
-		_deleteEntitySkeleton(reinterpret_cast<rage::fwEntity*>(obj));
+		auto removeSkeleton = true;
+
+		// Don't remove the skeleton if we're dropping a "weapon" with attached components.
+		if (const auto weapon = object->GetWeapon())
+		{
+			if (weapon->GetNumComponents() > 0)
+			{
+				removeSkeleton = false;
+			}
+		}
+
+		if (removeSkeleton)
+		{
+			_deleteEntitySkeleton(reinterpret_cast<rage::fwEntity*>(object));
+		}
 	}
 
-	return obj;
+	return object;
 }
 
 static HookFunction hookFunction([]
 {
-	auto location = hook::get_pattern("44 0F 29 6C 24 60 E8 ? ? ? ? 48", 6); 
-	hook::set_call(&g_origPedWeaponManagerDropWeapon, location);
-	hook::call(location, PedWeaponManagerDropWeapon);
+	{
+		auto location = hook::get_pattern("44 0F 29 6C 24 60 E8 ? ? ? ? 48", 6); 
+		hook::set_call(&g_origPedWeaponManagerDropWeapon, location);
+		hook::call(location, PedWeaponManagerDropWeapon);	
+	}
+
+	{
+		auto location = hook::get_pattern("74 18 B8 80 00 00 00 48 8B CB", -7);
+		g_objectWeaponPointerOffset = *reinterpret_cast<uint32_t*>(location);
+	}
+
+	{
+		auto location = hook::get_pattern("4D 85 C9 7E 20 48 8D B9 ? ? ? ? 48 8B C7", -6);
+		g_weaponNumComponentsOffset = *reinterpret_cast<uint32_t*>(location);
+	}
+
+#if _DEBUG
+	// Valid for 1604..3095 game builds.
+	assert(g_objectWeaponPointerOffset == (xbr::IsGameBuildOrGreater<2802>() ? 0x320 : 0x340));
+	assert(g_weaponNumComponentsOffset == (xbr::IsGameBuildOrGreater<2802>() ? 0x128 : 0x120));
+#endif
 });