From dff1ebaf21ae52e27e9915a26fbf535d3ab149ff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Janiszewski?=
 <janisozaur@users.noreply.github.com>
Date: Tue, 26 Mar 2019 23:46:08 +0100
Subject: [PATCH] Apply better guards for download queueing (#8864)

Follow-up to #8821.
Use mutex to synchronize access rather than make the bool atomic to
avoid TOCTOU issues.
---
 src/openrct2-ui/windows/ObjectLoadError.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/openrct2-ui/windows/ObjectLoadError.cpp b/src/openrct2-ui/windows/ObjectLoadError.cpp
index 3624587123..fa8ea6855a 100644
--- a/src/openrct2-ui/windows/ObjectLoadError.cpp
+++ b/src/openrct2-ui/windows/ObjectLoadError.cpp
@@ -34,6 +34,7 @@ private:
     std::vector<rct_object_entry> _downloadedEntries;
     size_t _currentDownloadIndex{};
     std::mutex _downloadedEntriesMutex;
+    std::mutex _queueMutex;
     bool _nextDownloadQueued{};
 
     // TODO static due to INTENT_EXTRA_CALLBACK not allowing a std::function
@@ -61,6 +62,7 @@ public:
 
     void Update()
     {
+        std::lock_guard guard(_queueMutex);
         if (_nextDownloadQueued)
         {
             _nextDownloadQueued = false;
@@ -87,6 +89,7 @@ private:
 
     void QueueNextDownload()
     {
+        std::lock_guard guard(_queueMutex);
         _nextDownloadQueued = true;
     }