Bug#322821: libpng12-0: new version breaks pdflatex

[Albert Cahalan <acahalan@gmail.com>]

> To sum things up: An update of libpng has caused tetex-bin (actually the
> pdftex binary) to fail when including a png image.  Since we (teTeX
> maintainers) made no changes, we suspected that it's a change in libpng,
> but there were no changes that could cause this, either.

The gimp is currently broken as well. It can't save PNG images.
In the xterm I started gimp from, I get this:

            libpng error: Call to NULL write function

I also get a dialog box like this:

--------------------------------------------------------
PNG image Message
Error while saving '/tmp/foo.png'. Could not save image.

GIMP Message
Saving '/tmp/foo.png' failed:
Plug-In could not save image

                                              OK
--------------------------------------------------------