Created attachment 1382693 [details]
Relevant part of Wayland journal

Description of problem:

I'm using Thunderbird on Fedora 27 x86-64, under Wayland. For a couple of months now I have had the problem where I'm resizing Thunderbird to make its window wider, and my entire session freezes. Moving the mouse has no effect; I still see the -->| icon for resizing, not aligned with the right edge of the window any more (because I just moved it), and nothing happens when I move the mouse or click on the mouse or the keyboard. I can still ssh in, though, so it is not an OS freeze. journal.log says that Xwayland has trapped; see attached.

If I wait a very long time (like, an hour), the screen starts getting artifacts. I might be able to move the mouse for a bit but then it freezes again.

Version-Release number of selected component (if applicable):
thunderbird-52.5.2-1.fc27.x86_64
xorg-x11-server-Xwayland-1.19.6-2.fc27.x86_64
libwayland-cursor-1.14.0-2.fc27.x86_64
I will attach a complete packages.out file.

How reproducible:
It is not easily reproducible.

Steps to Reproduce:
1. Start a Gnome session under Wayland.
2. Start Thunderbird and use it for a while.
3. Try to resize the window.

Actual results:

The entire UI freezes.

Expected results:

The Thunderbird window should get narrower, say.

Additional info:
See attachments.