Re: Add support for EXTRA_DIST_LINKS

[Karl Berry]

    I was thinking that an idea could be to change my patch in order to
    preserve symlinks only under --enable-maintainer-mode.

Seems ok to me, in principle. (Jim?)

The problem with making EXTRA_DIST_LINKS available in general is that,
invitably, packages will wrongly use it when creating tarballs for
public consumption. Thus I think it needs to be enabled only
conditionally.

For that matter, I'm not sure --enable-maintainer-mode is enough, but a
whole new strictness level ("developer") seems like overkill, and I
don't have any other ideas.

    package something *for another developer*? 
    [...] I do that regularly.

What symlinks do you actually use, in practice,
in such "developer tarballs"?


Also, there are some relatively minor shell unportabilities in the
patch, such as (just glancing through):

+       @if [ -n '$(EXTRA_DIST_LINKS)' ]; then \

It is Automake style to use "test ..." instead of "[ ... ]".

+             LINKDIR="$$(dirname "$${LNKPART}")"; \

It's not necessary to assume the dirname or basename commands, so we
don't. Sed suffices.  Also, we don't use $(...), but `...` (in
user-level code).

+             TGTABS="$$(realpath -m "$${TGTPART}")"; \

We can't assume realpath. Many systems do not have it.

+             while [ "$${TGTABS#"$${COMMONS}"}" = "$${TGTABS}" ]; do \

Such "advanced" variable expansions as "#" cannot be used.

Thanks,
Karl