Wayland: Only set selection when there is not already a source.

[tdaven]

Might fix #95649.

While trying to use the editor I got really frustrated with inconsistent clipboard behavior when using wayland. Often, when text has been selected and then copied, the paste afterwards results in nothing. Trying to copy again usually succeeds.

The best way I have found to reproduce is to copy/paste once, scroll with mouse wheel, try copy/paste again.

When the source selection was reused, wayland seems to send a cancel event for the old(see _wl_data_source_on_cancelled), which causes us to destroy the source (which obviously means we didn't send anything to the clipboard now). Since the selection is now cleared, the second attempt works.

Setting the selection only when there is not already a source seems to work.

[Riteo]

Thank you for the PR!

Sorry for not looking into this before, I somehow missed that issue 😅

Nothing in the spec seems to explicitly report this and I don't think I've ever noticed this behavior in sway, so I think that it might be some ambiguity in how the protocol's described.

My theory is that my executing wl_data_device::set_selection each time, the compositor "replaces" the current source and sends a cancelled event, which in turn destroys itself.

I think that the proper solution might be to avoid calling it if we already have a valid source, since it will be destroyed if something else replaces it.

[Riteo]

Code checks out! Note that you accidentally left a bunch of tabs in one line, before the TODO comment, making the CI fail:

(Uploaded a pic because I have no idea how to highlight that through markdown)

I'll formally approve once I make a quick test with sway to make sure that it didn't bring regressions there (it shouldn't).

[tdaven]

Always forget to run format when doing small edits....one day I'll remember.

[Riteo]

Always forget to run format when doing small edits....one day I'll remember.

BTW, we have pre-commit support now, which should do this automatically for each commit ;)

See https://docs.godotengine.org/en/stable/contributing/development/code_style_guidelines.html#pre-commit-hook

[Riteo]

Found no regressions on sway!

[Repiteo]

Thanks!