* Fix warning in cl_main.c

* Fix bug #4026 (SDL dx backend doesn't work on some machines)

code/sys/sys_local.h

@@ -48,6 +48,7 @@ unsigned int CON_LogRead( char *out, unsigned int outSize );
 char *Sys_StripAppBundle( char *pwd );
 #endif
 
+void Sys_GLimpSafeInit( void );
 void Sys_GLimpInit( void );
 void Sys_PlatformInit( void );
 void Sys_SigHandler( int signal );

code/sys/sys_unix.c

@@ -516,6 +516,18 @@ void Sys_ErrorDialog( const char *error )
 	FS_FCloseFile( f );
 }
 
+/*
+==============
+Sys_GLimpSafeInit
+
+Unix specific "safe" GL implementation initialisation
+==============
+*/
+void Sys_GLimpSafeInit( void )
+{
+	// NOP
+}
+
 /*
 ==============
 Sys_GLimpInit

code/sys/sys_win32.c

@@ -581,6 +581,25 @@ void Sys_ErrorDialog( const char *error )
 static qboolean SDL_VIDEODRIVER_externallySet = qfalse;
 #endif
 
+/*
+==============
+Sys_GLimpSafeInit
+
+Windows specific "safe" GL implementation initialisation
+==============
+*/
+void Sys_GLimpSafeInit( void )
+{
+#ifndef DEDICATED
+	if( !SDL_VIDEODRIVER_externallySet )
+	{
+		// Here, we want to let SDL decide what do to unless
+		// explicitly requested otherwise
+		_putenv( "SDL_VIDEODRIVER=" );
+	}
+#endif
+}
+
 /*
 ==============
 Sys_GLimpInit