Add string length checking to function COM_StripExtension. This fixes the R_RemapShader buffer overflow exploit that can be found here:

http://milw0rm.com/exploits/1750

code/renderer/tr_bsp.c

@@ -1823,7 +1823,7 @@ void RE_LoadWorldMap( const char *name ) {
 	Q_strncpyz( s_worldData.name, name, sizeof( s_worldData.name ) );
 
 	Q_strncpyz( s_worldData.baseName, COM_SkipPath( s_worldData.name ), sizeof( s_worldData.name ) );
-	COM_StripExtension( s_worldData.baseName, s_worldData.baseName );
+	COM_StripExtension(s_worldData.baseName, s_worldData.baseName, sizeof(s_worldData.baseName));
 
 	startMarker = ri.Hunk_Alloc(0, h_low);
 	c_gridVerts = 0;