dixSetPrivate regression

[Jeremy Huddleston]

Hi Tiago,

We're having some problems in XQuartz due to the privates changes.  Firstly, compilation fails.  The included patch causes the server to build, but we die inside dixSetPrivate from DRIWrapInit on launch:

Application Specific Information:
Assertion failed: (key->size == 0), function dixSetPrivate, file ../../../include/privates.h, line 147.

Thread 4 Crashed:
0   libSystem.B.dylib             	0x00007fff8191638d usleep$NOCANCEL + 0
1   libSystem.B.dylib             	0x00007fff8193597c abort + 93
2   libSystem.B.dylib             	0x00007fff819229b4 __pthread_markcancel + 0
3   X11.bin                       	0x000000010001c738 dixSetPrivate + 71
4   X11.bin                       	0x000000010001c6e5 DRIWrapInit + 179
5   X11.bin                       	0x000000010001a2b2 DRIFinishScreenInit + 233
6   X11.bin                       	0x000000010001fa50 xprSetupScreen + 68
7   X11.bin                       	0x0000000100015f01 QuartzSetupScreen + 35
8   X11.bin                       	0x0000000100011142 DarwinScreenInit + 595
9   X11.bin                       	0x0000000100149091 AddScreen + 884
10  X11.bin                       	0x0000000100011cde InitOutput + 204
11  X11.bin                       	0x0000000100131f27 dix_main + 571
12  X11.bin                       	0x0000000100018ddb server_thread + 64
13  libSystem.B.dylib             	0x00007fff81880456 _pthread_start + 331
14  libSystem.B.dylib             	0x00007fff81880309 thread_start + 13