Fixed the lost car bug with using the Town/World button

(http://www.nma-fallout.com/threads/fallout-2-vehicle-bug.217993/)

artifacts/ddraw.ini

@@ -650,10 +650,14 @@ UseWalkDistance=3
 ;Set to 1 to fix the bug of being unable to sell used geiger counters or stealth boys
 CanSellUsedGeiger=1
 
-;Set to 1 to fix the issue with being able to charge the car by using cells on other scenary/critters
+;Set to 1 to fix the issue with being able to charge the car by using cells on other scenery/critters
 ;Set to 0 if another mod you're using has custom vehicles
 CarChargingFix=1
 
+;Set to 1 to prevent the car from being lost when entering a location via the Town/World button and then leaving on foot
+;Note that the global variable 633 (GVAR_CAR_PLACED_TILE) will be set to -1 when the player leaves a location
+CarPlacedTileFix=1
+
 ;Set to 1 to skip weapon equip/unequip animations when performing various actions
 InstantWeaponEquip=0
 

sfall/FalloutEngine/Enums.h

@@ -159,6 +159,7 @@ enum GlobalVar : long
 	GVAR_NEW_RENO_SUPER_CAR = 456,
 	GVAR_MODOC_SHITTY_DEATH = 491,
 	GVAR_FALLOUT_2 = 494,
+	GVAR_CAR_PLACED_TILE = 633,
 };
 
 // Physical material type, used for items and tiles.

sfall/Modules/BugFixes.cpp

@@ -2252,6 +2252,20 @@ break:
 	}
 }
 
+static void __declspec(naked) wmInterfaceInit_hack() {
+	__asm {
+		mov  eax, GVAR_CAR_PLACED_TILE;
+		cmp  eax, dword ptr ds:[FO_VAR_num_game_global_vars];
+		jge  skip;
+		mov  edx, ds:[FO_VAR_game_global_vars];
+		lea  edx, [edx + eax * 4];
+		mov  dword ptr [edx], -1; // set gvar
+skip:
+		mov  edx, 12;
+		retn;
+	}
+}
+
 void BugFixes::init()
 {
 	#ifndef NDEBUG
@@ -2841,6 +2855,14 @@ void BugFixes::init()
 	// Fix for combat not ending automatically when there are no hostile critters
 	MakeCall(0x422CF3, combat_should_end_hack);
 	SafeWrite16(0x422CEA, 0x0C74); // jz 0x422CF8 (skip party members)
+
+	// Fix for the car being lost when entering a location via the Town/World button and then leaving on foot
+	// (sets GVAR_CAR_PLACED_TILE (633) to -1 on exit to the world map)
+	if (GetConfigInt("Misc", "CarPlacedTileFix", 1)) {
+		dlog("Applying car placed tile fix.", DL_INIT);
+		MakeCall(0x4C2367,  wmInterfaceInit_hack);
+		dlogr(" Done", DL_INIT);
+	}
 }
 
 }