Fix text copy via mouse click on Wayland

[soundslocke]

I've been working on a GPUI application which has a button for copying text. After starting the app in Wayland in Linux I noticed that when I click the button to copy text it does not work. After interacting with other buttons and/or copying text via keyboard shortcuts then my copy button works.

I thought I was handling something wrong, but then I noticed that Zed also exhibits this behavior: upon starting Zed if you highlight text and right-click and select "Copy" then nothing happens. After you interact with other UI elements and/or keyboard shortcuts then copy buttons seem to work fine.

This paper cut has been annoying me and with the help of Claude Code I arrived at this small fix. This solves the problem and this appears to be the way the serial should be handled for clipboard actions via button clicks in Wayland, as far as I've been able to learn. Here are a couple related Wayland documentation pages that I double checked:

1. https://wayland.app/protocols/wayland#wl_data_device:request:set_selection
2. https://wayland.freedesktop.org/docs/html/ch04.html#sect-Protocol-data-sharing-devices

• Added a solid test coverage and/or screenshots from doing manual testing

  • Here's a screen recording of the behavior without this fix:
    wayland-clipboard-problem.webm

  • Here's a screen recording of the behavior with this fix:
    wayland-clipboard-fix.webm

  • Here's a screen recording of the problem in Zed itself:
    wayland-clipboard-problem-zed.webm

• Done a self-review taking into account security and performance aspects

  • None that I could find or think of

• Aligned any UI changes with the UI checklist

  • I don't believe this is applicable...

Release Notes:

• Improved first mouse-driven text copy action on Wayland