Description of problem:
Screensaver crashed when trying to load after prescribed period of inactivity.

Version-Release number of selected component:
xscreensaver-gl-extras-5.22-1.fc19

Additional info:
reporter:       libreport-2.1.6
backtrace_rating: 4
cmdline:        glslideshow -window-id 31457332 -delay 20000 -duration 30 -zoom 75 -pan 6 -fade 2
crash_function: intel_miptree_attach_map
executable:     /usr/libexec/xscreensaver/glslideshow
kernel:         3.10.4-300.fc19.x86_64
runlevel:       N 5
uid:            1000

Truncated backtrace:
Thread no. 1 (10 frames)
 #0 intel_miptree_attach_map at intel_mipmap_tree.c:836
 #1 intel_miptree_map at intel_mipmap_tree.c:877
 #2 intel_map_renderbuffer at intel_fbo.c:129
 #3 map_attachment at ../../../src/mesa/swrast/s_renderbuffer.c:578
 #4 _swrast_map_renderbuffers at ../../../src/mesa/swrast/s_renderbuffer.c:652
 #5 _swrast_render_start at ../../../src/mesa/swrast/s_context.c:895
 #6 _swsetup_RenderStart at ../../../src/mesa/swrast_setup/ss_context.c:202
 #7 run_render at ../../../src/mesa/tnl/t_vb_render.c:276
 #8 _tnl_run_pipeline at ../../../src/mesa/tnl/t_pipeline.c:163
 #9 intelRunPipeline at intel_tris.c:1097