Comment 83 for bug 1181666

I'm not sure whether my bug is the same one or even related in its underlying cause. A program that I've helped write is exhibiting a constant failure to respond to mouse clicks in one subwindow that is implemented by an embedded mozilla browser window inside a Mono C# program. Keyboard input to that window works fine, but mouse clicks on a button are ignored. This appears to be related to the main form and controls down to the one hosting the mozilla browser all receiving WM_KILLFOCUS messages shortly after receiving WM_FOCUS messages when first clicking inside the window. Other desktop environments / window managers do not have this behavior in either ignoring the mouse clicks or receiving the spurious looking WM_KILLFOCUS messages. (For example, Unity, Cinnamon, XFCE, LXDE, and MATE all work fine. Unfortunately, none of them are the default for Ubuntu 18.04 which is what many of our users are upgrading to.)
The program can be found at https://github.com/BloomBooks/BloomDesktop for what it's worth. I know it's an unusual mix of C#, TypeScript, Pug, Less, etc. but it works fairly well under Ubuntu 16.04 with Unity or Cinnamon and under Ubuntu 18.04 with Cinnamon. It's quite frustrating for it to have this bizarre bug under the default desktop environment for Ubuntu 18.04.