Hello,

This issue pertains to the cube that is preloaded into the viewport when entering blender. I'm able to reproduce the problem by following these steps:

1. Run Blender :)
2. Tab for edit mode
3. Select "Face select mode"
4. A to select none.
5. Numpad 7 to view from top.
6. right click to select top face.
7. Numpad 1 to view from front.
8. E to extrude

At this point the xserver crashes. I'm running debian testing with xserver-org version 7.1.1. I was able to reproduce this issue on two computers with this configuration.

I've included some (hopefully) relevant info from kdm.log below.

Thanks very much!

------------------- begin kdm.log ----------------
Backtrace:
0: /usr/bin/X(xf86SigHandler+0x84) [0x80c4354]
1: [0xffffe420]
2: /usr/lib/xorg/modules/extensions/libGLcore.so(_swrast_write_rgba_span+0x89c) [0xa6f75b1c]
3: /usr/lib/xorg/modules/extensions/libGLcore.so [0xa6f6a23d]
4: /usr/lib/xorg/modules/extensions/libGLcore.so [0xa6f5f7ec]
5: /usr/lib/xorg/modules/extensions/libGLcore.so(_swrast_Line+0x23) [0xa6f5ec13]
6: /usr/lib/xorg/modules/extensions/libGLcore.so [0xa6fa02f1]
7: /usr/lib/xorg/modules/extensions/libGLcore.so(_tnl_RenderClippedLine+0x23) [0xa6fc14b3]
8: /usr/lib/xorg/modules/extensions/libGLcore.so [0xa6fba0f3]
9: /usr/lib/xorg/modules/extensions/libGLcore.so [0xa6fbd8da]
10: /usr/lib/xorg/modules/extensions/libGLcore.so [0xa6fc15b5]
11: /usr/lib/xorg/modules/extensions/libGLcore.so(_tnl_run_pipeline+0x13f) [0xa6fa7d8f]
12: /usr/lib/xorg/modules/extensions/libGLcore.so(_tnl_flush_vtx+0x2c5) [0xa6fd0855]
13: /usr/lib/xorg/modules/extensions/libGLcore.so(_tnl_FlushVertices+0x7c) [0xa6fcd91c]
14: /usr/lib/xorg/modules/extensions/libGLcore.so(_mesa_LoadMatrixf+0xa2) [0xa6f01aa2]
15: /usr/lib/xorg/modules/extensions/libglx.so [0xa7c32a86]
16: /usr/lib/xorg/modules/extensions/libglx.so(__glXRender+0xf3) [0xa7c29fd3]
17: /usr/lib/xorg/modules/extensions/libglx.so [0xa7c2ef6a]
18: /usr/bin/X(Dispatch+0x19b) [0x8086cab]
19: /usr/bin/X(main+0x489) [0x806e699]
20: /lib/tls/libc.so.6(__libc_start_main+0xc8) [0xa7d6bea8]
21: /usr/bin/X(FontFileCompleteXLFD+0xa9) [0x806d9d1]

Fatal server error:
Caught signal 11. Server aborting

------------------- end kdm.log ----------------