GNOME 42 - GTK4 support

[DimStar77]

GNOME 42 will have its nautilus application move to GTK4, which causes trouble with the dropbox-nautilus plugin (slight API changes for GTK4)

The two functions gtk_icon_theme_get_search_path and gtk_icon_theme_set_search_path are used by nautilus-dropbox, and those two are slightly different between GTK3 and GTK4

[rffontenelle]

Quoting Reminder for projects shipping a Nautilus extension: you must port to GTK4 from GNOME Discourse:

Nautilus 43 has been ported to GTK4. The port has changed the extensions API.

If your project ships a Nautilus extension then your build will break.

You have two options:

• port your project to the new Nautilus extension API
• gate the version requirement with libnautilus-extension < 43

Additionally, make sure to have a build configuration option to disable the Nautilus extension.

If you are building your project using a CI pipeline, you’re likely going to be using the stable version of Nautilus, so breakages will be noticed only when the release team tries to compose the full GNOME build. This will likely result in the release team disabling the Nautilus extension, if possible; if that’s not possible, your project will be skipped, and we are all going to be very sad.

[coreyberla]

The two functions gtk_icon_theme_get_search_path and gtk_icon_theme_set_search_path are used by nautilus-dropbox, and those two are slightly different between GTK3 and GTK4

There's a little bit more to it (not much).
#105