In traditional Git, I would keep the original commit author and add a Signed-off-by trailer as a Developer Certificate of Origin from me.
But Arcanist enforces its own format, which is not compatible with Git trailer lines.
About the first thing, indeed it's possible to git commit --amend --author=<firstname.lastname@example.org> Mrs. Foo" and it works and I suggest it to restore the original credit. I've done it a couple of times and it worked for me.
About the second thing, I think you are right. If I understand correctly, you are saying that, if you try to use this in the commit message, it does not work:
It may not work since arc diff thinks it's a section. Right?
In case, that is a bug! \o/ Feel free to file a Task under Arcanist.
As workaround, while waiting for a fix, maybe you can, whoops, forget the colon, and then it's safe for you to pretend to have forgotten it by mistake. Example:
I will sincerely trust you, and believe me, I think somebody will land that even if the syntax is not the canonical one. But indeed we will go straight to the hell for that. But I don't care of hell. So, feel free to do it.
arc diff throws an error and arc land ignores it. Instead of getting it to work with Differential, I'm amending the commit manually with git commit --amend -s after arc land --hold.
Commit message has errors: - Error parsing field "Subscribers": The objects you have listed include objects which do not exist (Signed-off-by:, ...