Comment 10 for bug 1233107

In order to test this you need a program which doesn't respond to NET_WM_PING.

A suitable test application is available here:

https://maemo.gitorious.org/fremantle-hildon-desktop/hildon-desktop/source/1be6ec951a4eed1d79878f88d2eacb298b447112:tests/test-hung-process.c

Compile it like this:

gcc -o test-hung-process test-hung-process.c `pkg-config --cflags --libs gtk+-2.0`

Run this command to set hostname:

sudo hostname aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

Log out and log in again to update environment. (Don't restart, hostname is not saved.)

Now when you start a shell you should see your new, long, hostname.

Run the test application, and when the window opens, click the close button. After a few seconds Xfwm will ask if you want to kill it. Click "yes".

Without patch, Xfwm will segfault after you click "yes". It will then restart and the hung window will still exist.

With the patch, the process will be killed as expected, and Xfwm won't crash.