From 483dc9de45d63184879cfe6a781bfb4a2d115e11 Mon Sep 17 00:00:00 2001
From: scrawl <scrawl@baseoftrash.de>
Date: Thu, 7 May 2015 23:17:30 +0200
Subject: [PATCH] Stop viewer threading before changing MyGUI textures

---
 apps/openmw/mwgui/windowmanagerimp.cpp    | 4 ++++
 components/myguiplatform/myguitexture.hpp | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/apps/openmw/mwgui/windowmanagerimp.cpp b/apps/openmw/mwgui/windowmanagerimp.cpp
index 6421df824..40180d700 100644
--- a/apps/openmw/mwgui/windowmanagerimp.cpp
+++ b/apps/openmw/mwgui/windowmanagerimp.cpp
@@ -1092,7 +1092,11 @@ namespace MWGui
             else if (it->first == "GUI" && it->second == "subtitles")
                 mSubtitlesEnabled = Settings::Manager::getBool ("subtitles", "GUI");
             else if (it->first == "GUI" && it->second == "menu transparency")
+            {
+                mViewer->stopThreading();
                 setMenuTransparency(Settings::Manager::getFloat("menu transparency", "GUI"));
+                mViewer->startThreading();
+            }
         }
     }
 
diff --git a/components/myguiplatform/myguitexture.hpp b/components/myguiplatform/myguitexture.hpp
index de385e94d..109858bc8 100644
--- a/components/myguiplatform/myguitexture.hpp
+++ b/components/myguiplatform/myguitexture.hpp
@@ -42,6 +42,8 @@ namespace osgMyGUI
 
         virtual void destroy();
 
+        /// @warning If you intend to change a texture during the frame update, you must either declare the texture with DataVariance::DYNAMIC
+        /// or temporarily stop the viewer threading, to prevent race conditions with the draw thread.
         virtual void* lock(MyGUI::TextureUsage access);
         virtual void unlock();
         virtual bool isLocked();