From 6fd2eb91a2194bc129717077f45afea34e0982f8 Mon Sep 17 00:00:00 2001
From: ZehMatt <m.moninger.h@gmail.com>
Date: Sat, 7 Oct 2017 14:48:54 +0200
Subject: [PATCH] Fix demolishing rides causing errors.

---
 src/openrct2/windows/RideConstruction.cpp | 29 ++++++++++++++++-------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/src/openrct2/windows/RideConstruction.cpp b/src/openrct2/windows/RideConstruction.cpp
index dfab8b936d..272850ff07 100644
--- a/src/openrct2/windows/RideConstruction.cpp
+++ b/src/openrct2/windows/RideConstruction.cpp
@@ -644,13 +644,24 @@ static void window_ride_construction_close(rct_window *w)
     hide_gridlines();
 
     uint8 rideIndex = _currentRideIndex;
-    if (ride_try_get_origin_element(rideIndex, nullptr)) {
-        Ride *ride = get_ride(rideIndex);
+    Ride * ride = get_ride(rideIndex);
+
+    // If we demolish a ride all windows will be closed including the construction window,
+    // the ride at this point is already gone.
+    if (ride == nullptr || ride->type == RIDE_TYPE_NULL)
+    {
+        return;
+    }
+
+    if (ride_try_get_origin_element(rideIndex, nullptr)) 
+    {
         // Auto open shops if required.
-        if (ride->mode == RIDE_MODE_SHOP_STALL && gConfigGeneral.auto_open_shops) {
+        if (ride->mode == RIDE_MODE_SHOP_STALL && gConfigGeneral.auto_open_shops) 
+        {
             // HACK: Until we find a good a way to defer the game command for opening the shop, stop this
             //       from getting stuck in an infinite loop as opening the ride will try to close this window
-            if (!_autoOpeningShop) {
+            if (!_autoOpeningShop) 
+            {
                 _autoOpeningShop = true;
                 ride_set_status(rideIndex, RIDE_STATUS_OPEN);
                 _autoOpeningShop = false;
@@ -658,14 +669,14 @@ static void window_ride_construction_close(rct_window *w)
         }
 
         ride_set_to_default_inspection_interval(rideIndex);
-
         window_ride_main_open(rideIndex);
-    } else {
-        sint32 eax = gGamePaused;
-
+    }
+    else 
+    {
+        sint32 previousPauseState = gGamePaused;
         gGamePaused = 0;
         ride_demolish(rideIndex, GAME_COMMAND_FLAG_APPLY);
-        gGamePaused = eax;
+        gGamePaused = previousPauseState;
     }
 }