Comment 2 for bug 1204261

StacktraceTop:
 sna_pixmap_set_dri (pixmap=0x7f8aff3a2f60, sna=0x7f8afda05000) at ../../../src/sna/sna_dri.c:189
 sna_dri_create_buffer (draw=<optimized out>, attachment=0, format=32) at ../../../src/sna/sna_dri.c:278
 create_buffer (format=32, attachment=0, pDraw=0x7f8aff39af00) at ../../../../hw/xfree86/dri2/dri2.c:448
 allocate_or_reuse_buffer (pDraw=pDraw@entry=0x7f8aff39af00, pPriv=pPriv@entry=0x7f8aff54ac70, attachment=attachment@entry=0, format=format@entry=32, dimensions_match=dimensions_match@entry=0, buffer=buffer@entry=0x7f8aff3a5b88, ds=<optimized out>) at ../../../../hw/xfree86/dri2/dri2.c:495
 do_get_buffers (pDraw=0x7f8aff39af00, width=width@entry=0x7fffbd7c3068, height=height@entry=0x7fffbd7c3070, attachments=0x7f8aff5a1d84, attachments@entry=0x7f8aff5a1d7c, count=1, out_count=out_count@entry=0x7fffbd7c3078, has_format=has_format@entry=1) at ../../../../hw/xfree86/dri2/dri2.c:608