Merge branch 'wip/smcv/transparent-is-transparent' into 'master'
authorMatthias Clasen <mclasen@redhat.com>
Thu, 2 Sep 2021 22:19:27 +0000 (22:19 +0000)
committerMatthias Clasen <mclasen@redhat.com>
Thu, 2 Sep 2021 22:19:27 +0000 (22:19 +0000)
reftest-compare: Treat colour channels as undefined if alpha is zero

Closes #4227

See merge request GNOME/gtk!3914


Trivial merge