[PATCH weston v2] configure.ac: fixup systemd/systemd-login detection

[Emil Velikov]

On 15 March 2018 at 17:23, Michael Tretter <m.tretter at pengutronix.de> wrote:
> On Thu, 15 Mar 2018 14:20:21 +0000, Emil Velikov wrote:
>> From: Emil Velikov <emil.velikov at collabora.com>
>>
>> Current systemd/systemd-login integration requires dbus. Although that
>> is far from clear the way current checks are handled.
>>
>> Be explicit and clear, effectively fixing cases where the systemd
>> auto detection will trip when dbus is explicitly disabled.
>>
>> Using git show -w will make things easier to read ;-)
>>
>> v2: auto disable systemd as dbus is missing
>>
>> Cc: Michael Tretter <m.tretter at pengutronix.de>
>> Reported-by: Michael Tretter <m.tretter at pengutronix.de>
>> Signed-off-by: Emil Velikov <emil.velikov at collabora.com>
>> ---
>> Thanks for the review Michael!
>>
>> You're right - the else hunk is only for consistency with surrounding
>> code.
>> ---
>>  configure.ac | 28 +++++++++++++++++-----------
>>  1 file changed, 17 insertions(+), 11 deletions(-)
>>
>> diff --git a/configure.ac b/configure.ac
>> index 0b326ccc..a3453d15 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -524,7 +524,12 @@ AC_ARG_ENABLE(systemd-login,
>>                AS_HELP_STRING([--enable-systemd-login],
>>                               [Enable logind support]),,
>>                enable_systemd_login=auto)
>> -if test x$enable_systemd_login != xno -a x$have_dbus != xno; then
>> +
>> +if test x$enable_systemd_login = xyes -a x$enable_dbus = xno; then
>> +  AC_MSG_ERROR([systemd-login support explicitly requested, but dbus not available])
>> +fi
>> +
>> +if test x$enable_systemd_login = xauto -a x$enable_dbus = xno; then
>
> If systemd-login is explicitly enabled, it will not enable
> systemd-login. The second condition is also wrong, because dbus must be
> enabled (or auto). It should read
>
>         if test x$enable_systemd_login != xno -a x$enable_dbus != xno; then
>
Indeed, things are fiddly and subtle.

Pekka pulled your simpler fix so this lovely patch can go in the bin.

Thanks
Emil