[systemd-devel] [PATCH] build-sys: merge libsystemd-login into libsystemd

[Kay Sievers]

On Fri, Jan 17, 2014 at 4:07 AM, Zbigniew Jędrzejewski-Szmek
<zbyszek at in.waw.pl> wrote:

> --- a/src/libsystemd/libsystemd.sym
> +++ b/src/libsystemd/libsystemd.sym
> @@ -7,8 +7,91 @@
>    (at your option) any later version.
>  ***/
>
> +/* Original symbols from systemd v31 */
> +
> +LIBSYSTEMD_LOGIN_31 {

Do I get this right? This exports the exact same symbols from the new lib?

This does not sound right. We should not try to be too smart here.

Symbol versions are supposed to avoid exactly the problem this will
create. The old symbols should not be provided by the new lib, to
allow the loading of the old and new lib into the same process without
clashes. We have no control which library is linked in over other
dependencies, it's very easy to end up with both libs in one process,
just by linking a third unrelated lib.

If backwards-compat is needed, it should be provided by a compat
package shipping the old lib, and not by double-exporting symbols from
the old and the new lib at the same time.

All this is nothing else in behavior than a SONAME bump, which is a
very common task for distros to solve. Actually it's exactly what a
distro is for, to solve these sorts of problems. Upstream packages
should not try to do magic things here, it just makes things too
fragile in the end.

Kay