[tlbuild] xdvi's dependency on libiconv

[Mojca Miklavec]

On Sun, Apr 20, 2014 at 11:26 PM, Karl Berry wrote:
>      # Check whether --with-iconv was given.
>     +with_iconv=no
>
> Isn't specifying --without-iconv equivalent?

Yes, but I wasn't sure how specifying top-level arguments in TeX
Live's ./Build influences building all the other libraries and
binaries. And I didn't know how to specify one extra flag for a single
program.

>     I would be grateful if this could be fixed,
>
> The xdvi configure checks if iconv is available, and uses it if it is.
> This seems like correct behavior to me.  The bug seems like having iconv
> available in the first place on systems where it is not needed.

I disagree. The correct behaviour would be to use when it is *needed*,
not when it is *present*. Otherwise any given build could
hypothetically link against all libraries present on the system.

>  Given
> that it is erroneously available but undesired,

It's not erroneously available. I imagine that the majority of
software depending on iconv would fail to build if iconv was absent.
The package is probably present "just in case" as part of third-party
package manager to avoid dealing with a number of packages
individually. I also found some references of software where the iconv
provided by the system isn't sufficient for some reason
(http://trac.sagemath.org/ticket/8191).

> I suppose a more complicated check could be to see if iconv is available
> in libc and not look for libiconv if it is in libc.  Or something like
> that.  If Paul feels like working on that, more power to him :).

Yes, that would probably be the correct approach.

On top of that I suspect that there might be another "problem", but I
don't know how to check, so maybe I'm wrong. On Solaris HAVE_ICONV_H
should probably be set to 1. I doubt that is currently the case when
libiconv is absent or when I use --with-iconv.

Solaris probably comes with /usr/include/iconv.h (or at least there is
such a file on the system I'm using, I assume it's part of a standard
installation).

Mojca