Killing a client in certain situation causes Weston segfaults.

Environment

• ArchLinux
• Wayland 1.16.0
• Weston 5.0.0

Steps to reproduce

Sorry, it is a bit complicated.

1. Run any desktop you normally use.
2. Run Weston inside (1).
3. Run any client inside (2).
4. Run one more any client inside (2).
5. Click (4) to put it on the top of (3).
6. Run any terminal inside (1) not inside (2).
7. Finally kill (4) using (6).

Expected result

The client(4) is killed and Weston(2) keeps running.

Actual result

The client(4) is killed and Weston(2) terminated by SIGSEGV.

Note

This seems to be very similar to #68 (closed).
I tried git bisecting and 85d55540 is the first affected commit.