Comment 8 for bug 1244324

Some more poking, it seems someone is changing drawable around..

create picture 0x1cd457e0, with drawable 0x1327d1f0
(some log spam removed, involving correct picture and drawable)
destroy picture 0x1cd457e0, with drawable 0x1cd65820 and private 0x1cd658e0 0 (nil)

Then finally, at the end when valgrind blows up, I get this:

Obtaining format for pixmap 0x1327d1f0 and picture 0x1cd457e0
==7989== Invalid read of size 4
==7989== at 0x8CAA0CA: glamor_get_tex_format_type_from_pixmap (glamor_utils.h:1252)
==7989== by 0x8CAD1B7: glamor_download_sub_pixmap_to_cpu (glamor_pixmap.c:1074)
==7989== by 0x8CA8BB7: _glamor_get_image (glamor_getimage.c:66)
==7989== by 0x8CA8D2F: glamor_get_image (glamor_getimage.c:92)
==7989== by 0x29AEF2: miSpriteGetImage (misprite.c:413)
==7989== by 0x1E7674: compGetImage (compinit.c:148)
==7989== by 0x1F5E5B: ProcShmGetImage (shm.c:684)
==7989== by 0x1F686F: ProcShmDispatch (shm.c:1121)
==7989== by 0x15D00D: Dispatch (dispatch.c:432)
==7989== by 0x14C569: main (main.c:298)
==7989== Address 0x1cd457f0 is 16 bytes inside a block of size 120 free'd
==7989== at 0x4C2B60C: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==7989== by 0x228897: FreePicture (picture.c:1477)
==7989== by 0x228B23: PictureDestroyWindow (picture.c:73)
==7989== by 0x234C19: damageDestroyWindow (damage.c:1646)
==7989== by 0x1E92C0: compDestroyWindow (compwindow.c:590)
==7989== by 0x20FF85: DbeDestroyWindow (dbe.c:1389)
==7989== by 0x185D46: FreeWindowResources (window.c:907)
==7989== by 0x1889A7: DeleteWindow (window.c:975)
==7989== by 0x17EBF1: doFreeResource (resource.c:873)
==7989== by 0x17FC1B: FreeClientResources (resource.c:1139)
==7989== by 0x15C4DE: CloseDownClient (dispatch.c:3402)
==7989== by 0x2AB843: CheckConnections (connection.c:1008)
==7989==
(II) fail to get matched format for dfdfdfdf

I guess the method of obtaining pixmap from a window drawable may result in not always returning the same pixmap, causing this bug...