confused about the png/APNG issue

Polytropon freebsd at edvax.de
Thu Aug 2 05:00:45 UTC 2012


On Wed, 1 Aug 2012 22:25:24 -0400, david coder wrote:
> one thing i don't understand about what otherwise seemed to me the best
> suggestion for dealing with this issue:  assuming that "the system png"
> refers to the png that comes w/ the freebsd distributions, how would
> upgrading the png port help?

The operating system FreeBSD (i. e. the base system) does _not_
come with a PNG library. You won't find it if you search through
the /usr/src tree (which contains the sources for all the stuff
in the base system).

The libpng is a 3rd party addition - a port (or a package) which
other software depends on. So if you need to update it, you need
to deal with the ports, not with the base system.

Unlike Linux, FreeBSD doesn't come in distributions. There is
_one_ base system. _THE_ operating system FreeBSD. It contains
of a defined set of components maintained by the FreeBSD team.



> wouldn't the other ports continue to use the
> system png?  there was, i know, a hint or two that upgrading old systems was
> a necessary part of the fix, but then why would the port matter @ all then,
> ie, why wouldn't updating the system be sufficient?

Such a procedure (i. e. updating the OS) _might_ be required to
get certain ports running. I'm not sure this is related to the
libpng issue, but basically it's _possible_ that such steps may
be needed for some software (which for example only runs on the
8- and 9- branch of the OS, but not on 7- anymore).

You need to understand that FreeBSD (the OS) is not arbitrarily
composed from packages like Linux distributions. In their context,
that what forms their base system (different among the distros!)
is created by selecting packages, and even the kernel can be seen
as a package. Many (most?) distros also include X and various
software, so they chose the PNG library to be part of that basic
distribution content.



> obviously, i'm confused.  will some patient person please explain where i'm
> going wrong?

I think it has been done hereby. :-)



-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...


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