[weston] configure.ac: Add support for new versions of systemd

[Javier Jardón]

> Hi,

Hi Pekka,

> let's get a bit more context, the whole systemd-login thing in
> configure.ac is:
>
> PKG_CHECK_MODULES(SYSTEMD_LOGIN, [libsystemd-login >= 198],
>                   [have_systemd_login=yes], [have_systemd_login=no])
> AS_IF([test "x$have_systemd_login" = "xyes"],
>       [AC_DEFINE([HAVE_SYSTEMD_LOGIN], [1], [Have systemd-login])])
> AM_CONDITIONAL(HAVE_SYSTEMD_LOGIN, test "x$have_systemd_login" = "xyes")
>
> PKG_CHECK_MODULES(SYSTEMD_LOGIN_209, [libsystemd-login >= 209],
>                   [have_systemd_login_209=yes], [have_systemd_login_209=no])
> AS_IF([test "x$have_systemd_login_209" = "xyes"],
>       [AC_DEFINE([HAVE_SYSTEMD_LOGIN_209], [1], [Have systemd-login >= 209])])
>
> You're saying that in a quite new version of systemd, there is no
> longer libsystemd-login.pc, right?

Yep

> Shouldn't we also fix the first test for >= 198?
> If you grep for SYSTEMD, you see most things using SYSTEMD_LOGIN and
> only few using SYSTEMD_LOGIN_209. The test for >= 198 is the main
> toggle.

Oh, good point, I will rework the patch

> Does libsystemd >= 209 guarantee "logind-dev" is there?

Yeah, they group all the pc files (libsystemd-daemon,
libsystemd-journal, libsystemd-login) inside a unique libsystemd.pc

Regards,
-- 
Javier Jardón Cabezas