Re: [PATCH 1/3] mergetool-lib: use $XDG_CURRENT_DESKTOP to check GNOME

>
> On Wed, Aug 5, 2020 at 3:51 PM Marco Trevisan (Treviño) via
> GitGitGadget <gitgitgadget@gmail.com> wrote:
> > To list merge tool candidates we used to use a private GNOME env
> > variable (GNOME_DESKTOP_SESSION_ID) that has been deprecated for long time ago
> > and removed as part of GNOME 3.30.0 release [1].
> >
> > So, git should instead check the XDG_CURRENT_DESKTOP env variable, that
> > is supported by all the desktop environments.
> >
> > Since the variable is actually a colon-separated list of names that the current
> > desktop is known as, we need to go through all the values to ensure
> > we're using GNOME.
> >
> > Signed-off-by: Marco Trevisan (Treviño) <mail@3v1n0.net>
> > ---
> > diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
> > @@ -266,6 +266,19 @@ run_merge_cmd () {
> > +is_desktop () {
> > +       IFS=':'
>
> We usually want to restore the value of IFS after we're done with it.
> For instance:
>
>     OLDIFS=$IFS
>     IFS=:
>
> and then restore it before returning:
>
>     IFS=$OLDIFS

> > +       for desktop in ${XDG_CURRENT_DESKTOP}
> > +       do
> > +               if test "$desktop" = "$1"
> > +               then
> > +                       return 0
> > +               fi
> > +       done
> > +
> > +       return 1
> > +}
>
> Rather than looping and mucking with IFS, even easier would be:
>
> is_desktop () {
>     case ":$XDG_CURRENT_DESKTOP:" in
>     *:$1:*) return 0 ;;
>     *) return 1 ;;
>     esac
> }
>
> But perhaps that's too magical for people?

> > @@ -275,7 +288,7 @@ list_merge_tool_candidates () {
> > -               if test -n "$GNOME_DESKTOP_SESSION_ID"
> > +               if is_desktop "GNOME"
>
> Why do we need to retire the $GNOME_DESKTOP_SESSION_ID check here,
> thus penalizing people who might still be on an old version of GNOME?
> It doesn't seem like it would be a maintenance burden to continue
> checking it while also taking advantage of $XDG_CURRENT_DESKTOP:
>
>     if test -n "$GNOME_DESKTOP_SESSION_ID" || is_desktop GNOME