Use absolute coordinates for temp position when north-walking (#4937)

Source/loadsave.cpp

@@ -431,10 +431,18 @@ void LoadPlayer(LoadHelper &file, Player &player)
 	player._pFireResist = file.NextLE<int8_t>();
 	player._pLghtResist = file.NextLE<int8_t>();
 	player._pGold = file.NextLE<int32_t>();
-
 	player._pInfraFlag = file.NextBool32();
-	player.position.temp.x = file.NextLE<int32_t>();
-	player.position.temp.y = file.NextLE<int32_t>();
+
+	int32_t tempPositionX = file.NextLE<int32_t>();
+	int32_t tempPositionY = file.NextLE<int32_t>();
+	if (player._pmode == PM_WALK_NORTHWARDS) {
+		// These values are saved as offsets to remain consistent with old savefiles
+		tempPositionX += player.position.tile.x;
+		tempPositionY += player.position.tile.y;
+	}
+	player.position.temp.x = static_cast<WorldTileCoord>(tempPositionX);
+	player.position.temp.y = static_cast<WorldTileCoord>(tempPositionY);
+
 	player.tempDirection = static_cast<Direction>(file.NextLE<int32_t>());
 	player.spellLevel = file.NextLE<int32_t>();
 	file.Skip<uint32_t>(); // skip _pVar5, was used for storing position of a tile which should have its HorizontalMovingPlayer flag removed after walking
@@ -1191,10 +1199,18 @@ void SavePlayer(SaveHelper &file, const Player &player)
 	file.WriteLE<int8_t>(player._pFireResist);
 	file.WriteLE<int8_t>(player._pLghtResist);
 	file.WriteLE<int32_t>(player._pGold);
-
 	file.WriteLE<uint32_t>(player._pInfraFlag ? 1 : 0);
-	file.WriteLE<int32_t>(player.position.temp.x);
-	file.WriteLE<int32_t>(player.position.temp.y);
+
+	int32_t tempPositionX = player.position.temp.x;
+	int32_t tempPositionY = player.position.temp.y;
+	if (player._pmode == PM_WALK_NORTHWARDS) {
+		// For backwards compatibility, save this as an offset
+		tempPositionX -= player.position.tile.x;
+		tempPositionY -= player.position.tile.y;
+	}
+	file.WriteLE<int32_t>(tempPositionX);
+	file.WriteLE<int32_t>(tempPositionY);
+
 	file.WriteLE<int32_t>(static_cast<int32_t>(player.tempDirection));
 	file.WriteLE<int32_t>(player.spellLevel);
 	file.Skip<int32_t>(); // skip _pVar5, was used for storing position of a tile which should have its HorizontalMovingPlayer flag removed after walking

Source/player.cpp

@@ -225,7 +225,7 @@ void WalkNorthwards(int pnum, const DirectionSettings &walkParams)
 {
 	Player &player = Players[pnum];
 	dPlayer[player.position.future.x][player.position.future.y] = -(pnum + 1);
-	player.position.temp = WorldTilePosition { static_cast<WorldTileCoord>(walkParams.tileAdd.deltaX), static_cast<WorldTileCoord>(walkParams.tileAdd.deltaY) };
+	player.position.temp = player.position.tile + walkParams.tileAdd;
 }
 
 void WalkSouthwards(int pnum, const DirectionSettings & /*walkParams*/)
@@ -669,7 +669,7 @@ bool DoWalk(int pnum, int variant)
 		switch (variant) {
 		case PM_WALK_NORTHWARDS:
 			dPlayer[player.position.tile.x][player.position.tile.y] = 0;
-			player.position.tile += { player.position.temp.x, player.position.temp.y };
+			player.position.tile = player.position.temp;
 			dPlayer[player.position.tile.x][player.position.tile.y] = pnum + 1;
 			break;
 		case PM_WALK_SOUTHWARDS: