46.1 regression: Wayland primary selection doesn't work well

Affected version

• OS: Arch Linux
• Mutter: 46.1
• Window system: Wayland

Bug summary

The wayland's primary selection copy-paste sometimes doesn't work when the window is maximized or full screen.

Steps to reproduce

1. Open a gnome-terminal and maximized or full screen window.
2. Open a gedit.
3. Selection a text in gnome-terminal.
4. Switch to gedit window and click mouse middle button.
5. Repeats step 3 and step 4.

What happened

Sometimes the text pasted into gedit is not the latest selected.

What did you expect to happen

Always paste latest selected text.

Relevant logs, screenshots, screencasts etc.

This issue is caused by patch 9bdb00c4 (!3707 (merged))