Please describe the problem:
The code for gdk_rgb_preprocess_dm_565 contains:

static void
gdk_rgb_preprocess_dm_565 (void)
{
  int i;
  guint32 dith;

  if (DM_565 == NULL)
    {
      DM_565 = g_new (guint32, DM_WIDTH * DM_HEIGHT);

The data entered into the array is constant. It should be declared as a const
array with the values precomputated, so that you don't have to malloc for everyone. 

Steps to reproduce:
Run valgrind on an application that hits this spot, use --show-reachable=yes.

Actual results:
==26327== 65536 bytes in 1 blocks are still reachable in loss record 13948 of 13952
==26327==    at 0x3414A584: malloc (in /usr/lib/valgrind/vgpreload_addrcheck.so)
==26327==    by 0x341A0E86: g_malloc (in /opt/gnome/lib/libglib-2.0.so.0.400.6)
==26327==    by 0x357E25CD: gdk_rgb_preprocess_dm_565 (gdkrgb.c:1114)
==26327==    by 0x357E57F3: gdk_rgb_select_conv (gdkrgb.c:2919)
==26327==    by 0x357E1E5D: gdk_rgb_create_info (gdkrgb.c:678)
==26327==    by 0x357E1F64: gdk_rgb_get_info_from_colormap (gdkrgb.c:716)
==26327==    by 0x357E1FA1: gdk_rgb_xpixel_from_rgb_internal (gdkrgb.c:727)
==26327==    by 0x357E22F7: gdk_rgb_find_color (gdkrgb.c:825)

Expected results:
No such allocation

Does this happen every time?
Yes

Other information: