On Wed, Mar 30, 2016 at 01:31:21AM +0200, Rafal Luzynski wrote:
> 29.03.2016 16:31 "Dmitry V. Levin" <ldv@altlinux.org> wrote:
> > On Fri, Mar 25, 2016 at 01:55:13AM +0100, Rafal Luzynski wrote:
> > [...]
> > > This means that all applications using %B to retrieve the month
> > > name standalone should use %OB from now.
> >
> > Such applications as cal(1) would not be able to print month names
> > properly in a way that would work with different glibc versions.
> > Looks like this is a change incompatible in both ways.
> 
> Yes, that's exactly what will happen. Such applications must be
> updated. They must start using strftime("%OB") and nl_langinfo(ALTMON_...).
> They must either detect the glibc version at runtime and choose
> the correct format specifier or require the minimum glibc version
> at build time. I'm willing to contact the upstream developers and
> provide the instructions how to change their applications.

In glibc, we don't make changes this way.  If an incompatible ABI change
is introduced, the old ABI remains for compatibility with software linked
with it.

With regards to runtime checks, could you give an example of such a check?


-- 
ldv