Please attach (as opposed to paste) the output of

LIBGL_DEBUG=verbose glxinfo

(In reply to comment #1)
> Please attach (as opposed to paste) the output of
> 
> LIBGL_DEBUG=verbose glxinfo

kiev1@k1h ~ $ LIBGL_DEBUG=verbose glxinfo
name of display: :0.0
display: :0  screen: 0
direct rendering: No
server glx vendor string: SGI
server glx version string: 1.2
server glx extensions:
    GLX_ARB_multisample, GLX_EXT_visual_info, GLX_EXT_visual_rating,
    GLX_EXT_import_context, GLX_EXT_texture_from_pixmap, GLX_OML_swap_method,
    GLX_SGI_make_current_read, GLX_SGIS_multisample, GLX_SGIX_hyperpipe,
    GLX_SGIX_swap_barrier, GLX_SGIX_fbconfig
client glx vendor string: SGI
client glx version string: 1.4
client glx extensions:
    GLX_ARB_get_proc_address, GLX_ARB_multisample, GLX_EXT_import_context,
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_MESA_allocate_memory,
    GLX_MESA_copy_sub_buffer, GLX_MESA_swap_control,
    GLX_MESA_swap_frame_usage, GLX_OML_swap_method, GLX_OML_sync_control,
    GLX_SGI_make_current_read, GLX_SGI_swap_control, GLX_SGI_video_sync,
    GLX_SGIS_multisample, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer,
    GLX_SGIX_visual_select_group, GLX_EXT_texture_from_pixmap
GLX version: 1.2
GLX extensions:
    GLX_ARB_get_proc_address, GLX_ARB_multisample, GLX_EXT_import_context,
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_OML_swap_method,
    GLX_SGI_make_current_read, GLX_SGIS_multisample, GLX_SGIX_fbconfig,
    GLX_EXT_texture_from_pixmap
OpenGL vendor string: Mesa project: www.mesa3d.org
OpenGL renderer string: Mesa GLX Indirect
OpenGL version string: 1.2 (1.5 Mesa 6.5)
OpenGL extensions:
    GL_ARB_depth_texture, GL_ARB_imaging, GL_ARB_multitexture,
    GL_ARB_point_parameters, GL_ARB_point_sprite, GL_ARB_shadow,
    GL_ARB_shadow_ambient, GL_ARB_texture_border_clamp,
    GL_ARB_texture_cube_map, GL_ARB_texture_env_add,
    GL_ARB_texture_env_combine, GL_ARB_texture_env_crossbar,
    GL_ARB_texture_env_dot3, GL_ARB_texture_mirrored_repeat,
    GL_ARB_texture_non_power_of_two, GL_ARB_texture_rectangle,
    GL_ARB_transpose_matrix, GL_ARB_window_pos, GL_EXT_abgr, GL_EXT_bgra,
    GL_EXT_blend_color, GL_EXT_blend_func_separate, GL_EXT_blend_logic_op,
    GL_EXT_blend_minmax, GL_EXT_blend_subtract, GL_EXT_clip_volume_hint,
    GL_EXT_copy_texture, GL_EXT_draw_range_elements, GL_EXT_fog_coord,
    GL_EXT_framebuffer_object, GL_EXT_multi_draw_arrays, GL_EXT_packed_pixels,
    GL_EXT_point_parameters, GL_EXT_polygon_offset, GL_EXT_rescale_normal,
    GL_EXT_secondary_color, GL_EXT_separate_specular_color,
    GL_EXT_shadow_funcs, GL_EXT_stencil_wrap, GL_EXT_subtexture,
    GL_EXT_texture, GL_EXT_texture3D, GL_EXT_texture_edge_clamp,
    GL_EXT_texture_env_add, GL_EXT_texture_env_combine,
    GL_EXT_texture_env_dot3, GL_EXT_texture_lod_bias, GL_EXT_texture_object,
    GL_EXT_texture_rectangle, GL_EXT_vertex_array, GL_APPLE_packed_pixels,
    GL_ATI_texture_env_combine3, GL_ATI_texture_mirror_once,
    GL_ATIX_texture_env_combine3, GL_IBM_texture_mirrored_repeat,
    GL_INGR_blend_func_separate, GL_MESA_pack_invert, GL_MESA_ycbcr_texture,
    GL_NV_blend_square, GL_NV_point_sprite, GL_NV_texgen_reflection,
    GL_NV_texture_rectangle, GL_SGIS_generate_mipmap,
    GL_SGIS_texture_border_clamp, GL_SGIS_texture_edge_clamp,
    GL_SGIS_texture_lod, GL_SGIX_depth_texture, GL_SGIX_shadow,
    GL_SGIX_shadow_ambient, GL_SUN_multi_draw_arrays
glu version: 1.3
glu extensions:
    GLU_EXT_nurbs_tessellator, GLU_EXT_object_space_tess

   visual  x  bf lv rg d st colorbuffer ax dp st accumbuffer  ms  cav
 id dep cl sp sz l  ci b ro  r  g  b  a bf th cl  r  g  b  a ns b eat
----------------------------------------------------------------------
0x23 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  0  0  0  0  0  0 0 None
0x24 24 tc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16  0  0 0 None
0x25 24 tc  0 32  0 r  y  .  8  8  8  8  0 16  8 16 16 16 16  0 0 None
0x26 24 tc  0 32  0 r  .  .  8  8  8  8  0 16  8 16 16 16 16  0 0 None
0x27 24 dc  0 24  0 r  y  .  8  8  8  0  0 16  0  0  0  0  0  0 0 None
0x28 24 dc  0 24  0 r  y  .  8  8  8  0  0 16  8 16 16 16  0  0 0 None
0x29 24 dc  0 32  0 r  y  .  8  8  8  8  0 16  8 16 16 16 16  0 0 None
0x2a 24 dc  0 32  0 r  .  .  8  8  8  8  0 16  8 16 16 16 16  0 0 None
0x65 32 tc  0 32  0 r  .  .  8  8  8  8  0  0  0  0  0  0  0  0 0 Ncon

> direct rendering: No

Thank You,
It is a problem
direct rendering: no
- added in xorg.conf Load  "dri" - and all began to work

The bug still stands.  You're just bypassing it with direct rendering.

I think I found the problem - a bad test in __indirect_glClientActiveTextureARB().  

The wrong inequality is used to test against num_texture_units.  I'll check in
the fix.

Still, the real bug may be in FlightGear if it's trying to specify a texture
coordinate array for a non-existant texture unit.

I'll leave this open for a bit longer.

OK, I think I found the _real_ cause of this bug.  The 'index' field was not
getting pushed in __glXPushArrayState() but we're using it in
__glXPopArrayState().  The value was garbage then.
Closing now.