1 files changed, 19 insertions, 1 deletions
diff --git a/indra/llwindow/llwindowwin32.cpp b/indra/llwindow/llwindowwin32.cpp
index bacf5325fe..70bdb25415 100644
--- a/indra/llwindow/llwindowwin32.cpp
+++ b/indra/llwindow/llwindowwin32.cpp
@@ -343,6 +343,7 @@ struct LLWindowWin32::LLWindowWin32Thread : public LL::ThreadPool
     LLWindowWin32Thread();
 
     void run() override;
+    void close() override;
 
     // Detroys handles and window
     // Either post to or call from window thread
@@ -407,6 +408,7 @@ struct LLWindowWin32::LLWindowWin32Thread : public LL::ThreadPool
     // until after some graphics setup. See SL-20177. -Cosmic,2023-09-18
     bool mGLReady = false;
     bool mGotGLBuffer = false;
+    bool mShuttingDown = false;
     LLAtomicBool mDeleteOnExit = false;
 };
 
@@ -4587,11 +4589,25 @@ std::vector<std::string> LLWindowWin32::getDynamicFallbackFontList()
 #endif // LL_WINDOWS
 
 inline LLWindowWin32::LLWindowWin32Thread::LLWindowWin32Thread()
-    : LL::ThreadPool("Window Thread", 1, MAX_QUEUE_SIZE, false)
+    : LL::ThreadPool("Window Thread", 1, MAX_QUEUE_SIZE, true /*should be false, temporary workaround for SL-18721*/)
 {
     LL::ThreadPool::start();
 }
 
+void LLWindowWin32::LLWindowWin32Thread::close()
+{
+    LL::ThreadPool::close();
+    if (!mShuttingDown)
+    {
+        LL_WARNS() << "Closing window thread without using destroy_window_handler" << LL_ENDL;
+        // Workaround for SL-18721 in case window closes too early and abruptly
+        LLSplashScreen::show();
+        LLSplashScreen::update("..."); // will be updated later
+        mShuttingDown = true;
+    }
+}
+
+
 /**
  * LogChange is to log changes in status while trying to avoid spamming the
  * log with repeated messages, especially in a tight loop. It refuses to log
@@ -4835,6 +4851,8 @@ bool LLWindowWin32::LLWindowWin32Thread::wakeAndDestroy()
         return false;
     }
 
+    mShuttingDown = true;
+
     // Make sure we don't leave a blank toolbar button.
     // Also hiding window now prevents user from suspending it
     // via some action (like dragging it around)