Replace defaults.list by mimeapps.list

Status changed to 'Confirmed' because the bug affects multiple users.

@seb128 how about changing /etc/gnome/defaults.list by mimeapps.list in Ubuntu 23.10 (Mantic) release cycle?
Other Linux distributions already use mimeapps.list , see comment on upstream source code - https://gitlab.gnome.org/GNOME/glib/-/blob/main/gio/gdesktopappinfo.c#L1021 :

  /* We have 'defaults.list' which was only ever understood by GLib. It
   * exists widely, but it has never been part of any spec and it should
   * be treated as deprecated. This will be removed in a future version.
   */

I'm setting block-proposed because I want this to roughly land in Noble at the same time as the gnome-session update.

This bug was fixed in the package gnome-session - 46.0-1ubuntu1

---------------
gnome-session (46.0-1ubuntu1) noble; urgency=medium

  * Merge with Debian. Remaining changes:
    - debian/control.in:
      + Recommend session-migration
      + Move xwayland dependency to gnome-session and make gnome-session
        Arch: any
      + Split gnome-startup-applications to a separate binary package so
        that it can be uninstalled without breaking the system
      + Add unity-session
    - debian/rules: Ensure pot file is generated to translate session files
    - Split ubuntu-session out of gnome-session.
    - debian/data: Add old-style systemd user session used by Unity
    - debian/gnome-session-bin.postinst, debian/gnome-session-bin.prerm:
       Moved registering gnome-session binary as a session manager to
       gnome-session-bin package
    - debian/patches/ubuntu/support_autostart_delay.patch:
      + Bugzilla patch to support adding a delay to autostart apps, using
        a "X-GNOME-Autostart-Delay" key in the desktop file
    - debian/patches/ubuntu/ubuntu_sessions.patch:
      + Add ubuntu sessions
    - debian/patches/ubuntu/remove_session_saving_from_gui.patch:
      + Add GNOME_SESSION_SAVE environment variable for people wanting to
        use the save session still, knowing that it can break your system
        if used unwisely
    - debian/patches/ubuntu/add_sessionmigration.patch:
      + launch session-migration if present at the start of the session.
        This sync tool runns different session migration scripts that can be
        provided in various desktop packages.
    - debian/patches/ubuntu/dbus_request_shutdown.patch:
      + Add "RequestShutdown" and "RequestReboot" DBus methods to allow
        other applications to shutdown or reboot the machine via the session
        manager.
    - debian/patches/ubuntu/ignore_gsettings_region.patch:
      + Ignore the "region" gsettings value - users' setting of LC_*
        variables saved in ~/.pam_environment.
    - debian/patches/revert_remove_gnome_session_properties.patch:
      + Don't merge translations into gnome-session-properties.desktop
    - debian/ubuntu-settings-migrate-to-defaults.18.10.1.py:
      + Migrate users using old default ubuntu-settings to current ones
    - debian/xdg_dirs_desktop_session.sh: Install a new script into
      /etc/profile.d to prepend a $DESKTOP_SESSION related directory to
      $XDG_{CONFIG,DATA}_DIRS.
  * Drop revert portal change patch: not needed in Ubuntu
  * Mark the Ubuntu sessions as supporting GNOME 46 Remote Login

gnome-session (46.0-1) unstable; urgency=medium

  * New upstream release
  * Add patch to revert portal change since Debian Unstable does not have
    GNOME Shell or xdg-desktop-portal-gnome 46 yet
  * gnome-mimeapps.list: several updates for firefox, thunderbird, & gdebi
  * Release to unstable

 -- Jeremy Bícha <email address hidden> Thu, 21 Mar 2024 18:52:22 -0400

This bug was fixed in the package desktop-file-utils - 0.27-2

---------------
desktop-file-utils (0.27-2) unstable; urgency=medium

  * Team upload
  * Add debian/conffiles to remove /etc/gnome/defaults.list (LP: #1559129)
  * Drop unused Build-Depends: libpopt-dev

desktop-file-utils (0.27-1) unstable; urgency=low

  * New upstream release.
  * Drop obsolete lintian overrides.
  * Update watch file to version 4.

 -- Jeremy Bícha <email address hidden> Thu, 29 Feb 2024 18:14:11 -0500