Since older versions of our GIMP dds file exporter incorrectly
saved BC5 dds images with the red and green channels
swapped we should fix that. Since the exporter already
wrote the plug-ins version number and that it is written by
GIMP we can check for these incorrect images.
To enable that we increase the plug-ins revision in this
commit and swap red and green channels for images
that have an older version number and are of the
correct type.
(cherry picked from commit a4cc8b7070)
# Conflicts:
# plug-ins/file-dds/dds.h
Still a lot more to do but pushing WIP to not have it wasted if more
commits come in from others.
Also got rid of some global variables.
(cherry picked from commit ff2d22d915)
None of our load plug-ins have such a checkbox, so this is not
consistent. Moreover one you uncheck it, you just can't get back the
dialog until next GIMP restart. That's very bad usability.
(cherry picked from commit 948608e658)
