The first glibc 2.2 backwards compatbility problem....
So here's the first glibc 2.2 backwards compatiblity problem that's come
up, according to HJ Lu.....
>RedHat 7.0 uses glibc 2.2. There are some subtle changes from glibc
>2.1 to 2.2. One of them is errno. From the glibc manual:
> The initial value of `errno' at program startup is zero. Many
> library functions are guaranteed to set it to certain nonzero
> values when they encounter certain kinds of errors. These error
> conditions are listed for each function. These functions do not
> change `errno' when they succeed;
>This is no longer true in glibc 2.2. `errno' can change after the
>return from a glibc function, successful or not. Any applications
>depending the old documented glibc behavior may fail with glibc 2.2.
>So far, I have found elm is one of them:
>I don't like this change. My concern is although the glibc manual
>shouldn't have said "These functions do not change `errno' when they
>succeed;" in the first place, changing the application source code
>may not be an option for every Linux user. Glibc has to provide the
>backward compatibility on this. But most of glibc developers don't
>share my view.
What if anything should we say in the specification about this? If we
decide to use glibc 2.2 as our base specification, I think we're going
to need to start an appendix listing differences between glibc 2.1 and
2.2. I ***hope*** that there aren't too many of these compatibility
land mines hiding in glibc 2.2.
P.S. My other big concern is that RedHat apparently shipped a
pre-release of 2.2 (i.e., 2.1.91). Given that Ulrich works for RedHat I
hope that someone at RH got Ulrich to sign a contract in blood stating
that there will be no compatibility problems introduced between 2.1.91
and 2.2. Otherwise, this has the potential for causing a really big