Short version:
If you see "PNG IDAT errors" like:
program: IDAT: invalid distance too far back `test1.png' @
WARNING **: Icon test1 missing: (0) Fatal error reading PNG image file:
Decompression error in IDAT
Then you should use >=media-gfx/pngcrush-1.7.57 built with
USE="-system-libs" to it's using libpng 1.5.15 to correct the IDAT in
the .png files using command:
$ pngcrush -fix -force old.png new.png
These bogus images were visible with libpng15 and earlier but now that
improved code was committed these bogus files stopped showing as a
side-effect. If I understood correct this is not going to be fixed in
the library itself. Caused by slightly bad combination of libpng and
zlib and some tool.
Long version:
http://bugs.gentoo.org/466190
http://bugzilla.gnome.org/show_bug.cgi?id=698286
+ the ML links mentioned in the bugs
Figured this is useful for every maintainer to know.
