Properly destroy OpenGL resources on linux (thx @curaga for the patch with id 3539332)

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4257 dfc29bdd-3216-0410-991c-e03cc46cb475

changes.txt

@@ -1,5 +1,7 @@
 Changes in 1.8 (??.??.2011)
 
+ - Properly destroy OpenGL resources on linux (thx @curaga for the patch)
+
  - Fix diplay bux in the attribute-panel of the GUIEditor. Fixes bug 3517314 (thx @Darkcoder  for reporting).
 
  - Allow caching cursor position on X11 to work around slow XQueryPointer calls (thx @Hendu for reporting+patch proposal)

source/Irrlicht/CIrrDeviceLinux.cpp

@@ -11,6 +11,8 @@
 #include <sys/utsname.h>
 #include <time.h>
 #include "IEventReceiver.h"
+#include "ISceneManager.h"
+#include "IGUIEnvironment.h"
 #include "os.h"
 #include "CTimer.h"
 #include "irrString.h"
@@ -140,6 +142,24 @@ CIrrDeviceLinux::~CIrrDeviceLinux()
 		CursorControl->setVisible(false);
 		static_cast<CCursorControl*>(CursorControl)->clearCursors();
 	}
+
+	// Must free OpenGL textures etc before destroying context, so can't wait for stub destructor
+	if ( GUIEnvironment )
+	{
+		GUIEnvironment->drop();
+		GUIEnvironment = NULL;
+	}
+	if ( SceneManager )
+	{
+		SceneManager->drop();
+		SceneManager = NULL;
+	}
+	if ( VideoDriver )
+	{
+		VideoDriver->drop();
+		VideoDriver = NULL;
+	}
+
 	if (display)
 	{
 		#ifdef _IRR_COMPILE_WITH_OPENGL_