metacity hangs after application calls XSetTransitionForHint()

Hello,

I noticed a very strange bug when programming Xlib directly. A combination of calls that set NET_WM_STATE_MODAL=1 and XSetTransientForHint(window,window) (not always) causes a hang of metacity. Neither killing the program that made these calls, nor anything else except killing Xorg server helps. Please find attached a source code of a primitive program that causes metacity to hang on my 12.04. Compile it with "gcc -o hang_xorg hang_xorg.c -lX11" .

Sincerely,
   Dmitry Karasik

<email address hidden>

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: metacity 1:2.34.1-1ubuntu11
ProcVersionSignature: Ubuntu 3.2.0-53.81-generic 3.2.50
Uname: Linux 3.2.0-53-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.5
Architecture: amd64
Date: Wed Oct 23 13:34:32 2013
InstallationMedia: Ubuntu 10.04.4 LTS "Lucid Lynx" - Release amd64 (20120214.2)
MarkForUpload: True
SourcePackage: metacity
UpgradeStatus: Upgraded to precise on 2013-05-15 (161 days ago)