fix crash handler not always being installed properly

try to shut down sdl

stepmania/src/arch/ArchHooks/ArchHooks_Unix.cpp

@@ -2,17 +2,30 @@
 #include "ArchHooks_Unix.h"
 #include "archutils/Unix/SignalHandler.h"
 
-#if defined(HAVE_BACKTRACE)
+#if defined(CRASH_HANDLER)
 #include "archutils/Unix/CrashHandler.h"
 #endif
 
+#include "SDL_utils.h"
+
+static void EmergencyShutdown( int signal )
+{
+	/* If we don't actually use SDL for video, this should be a no-op. */
+	if( SDL_WasInit(SDL_INIT_VIDEO) )
+		SDL_QuitSubSystem(SDL_INIT_VIDEO);
+}
+	
 ArchHooks_Unix::ArchHooks_Unix()
 {
-#if defined(HAVE_BACKTRACE)
+#if defined(CRASH_HANDLER)
 	CrashHandlerHandleArgs();
 
 	SignalHandler::OnClose( CrashSignalHandler );
 #endif
+
+	/* Set up EmergencyShutdown, to try to shut down the window if we crash.
+	 * This might blow up, so be sure to do it after the crash handler. */
+	SignalHandler::OnClose( EmergencyShutdown );
 }
 
 /*