Description of problem:

Several png images (e.g. 4 out of a set of 15) do not display any more (correctly displayed until recently) on a fully updated cauldron system (as of 13.6.2016 and using lib64png16_16-1.6.22):
  - as images in a browser home page - now displayed by Firefox as blank,
  - when opened with Gimp - gimp displays the png file as some clobbered nonsense
  - dito with Gwenview

Similar problem in a fully updated Mageia-5 system. But the icons display correctly if I use the Mageia-5 system on my laptop that has not yet been updated and still uses lib64png16_16-1.6.20.

As a workaround, the png image files can be "fixed" and than display correctly on cauldron by the following sequence of actions:
 1. open the png image with Gimp on a system that uses lib64png16_16-1.6.20,
 2. and than create a corresponding xcf file,
 3. open that xcf file with Gimp on the system that uses lib64png16_16-1.6.22 (cauldron) (updated libpng)
 4. export the image as a new png image.

This newly created png file displays correctly on all systems which seems to indicate that the images themselves are OK, and that the problem appears to be an inconsistency in the handling of the png files by between the old and the new png library.

Joining 3 attachments:
- aonLogo_old.png ... old image file that does not display correctly on cauldron
- aonLogo.xcf ... image file created from aonLogo.old (using lib64png16_16-1.6.20)
- aonLogo_new.png ... image file exported by gimp using lib64png-1.6.22

Version-Release number of selected component (if applicable):


How reproducible:
100%

Steps to Reproduce:
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