As IgorBeghetto recommended, I checked into GIT the change of 0xff to 0x00 in virtualvconsole.C as Andrew provided in his patch " 0001-background-clear-in-vconsole-must-be-set-to-0.patch". It will be easy to undo if Igor and his computer, Charlie, find a problem with it. (Actually I never figured out how to back something out of GIT, I just add back the original).
try 'git revert hash' as in
git revert 8dfg44f
just where hash is first 8 digits or more from commit id as seen in git log.
it should bring up your editor so you can write additional reason for reverting. After saving text there commit with revert and your note will be written to git. Just as with normal git commit you probably can escape at last moment by pressing escape in editor, but this will leave your tree in some need for
'git reset --hard old_hash' where old_hash is good commit before you strted aborted command.
Good find by Goat and glad Andrea and IgorBeghetto were able to see that the correction fixes render using PNG, EXR, and TGA. (I still wonder what "Goat" stands for?).