Quartz fix: ut2004 makes a 2D window for the splash screen, which sets the screen surface's pixels field. Then we tear down that video mode and create a GL context, and the Quartz target isn't resetting the pixels field to NULL. When you just create a GL window, the structure is memset'd to zero the first time through, so unless you hit ut2004's codepath, you won't see the bug. :) Without this patch, quitting a windowed ut2003/ut2004 game makes the OS dump a warning about a bogus free() to stderr, but it doesn't actually crash. All we need to do is explicitly initialize the current->pixels field.

#if defined(USE_ASM_MIXER_VC)
// headers for MMX assembler version of SDL_MixAudio
// Copyright 2002 Stephane Marchesin (stephane.marchesin@wanadoo.fr)
// Converted to Intel ASM notation by Cth
// This code is licensed under the LGPL (see COPYING for details)
// 
// Assumes buffer size in bytes is a multiple of 16
// Assumes SDL_MIX_MAXVOLUME = 128

void SDL_MixAudio_MMX_S16_VC(char* ,char* ,unsigned int ,int );
void SDL_MixAudio_MMX_S8_VC(char* ,char* ,unsigned int ,int );
#endif