With -overwrite-original-in-place, what happens on a write error? Is the result corrupt? Does it move the temporary copy on top? Does it have a backup it can restore?

I'm thinking about the case where another process happens to fill the filesystem at the same time you're doing the final overwrite. Do you do the final overwrite with O_TRUNC, or do you leave the full file size around? Do you truncate out to the final length if the image has grown?

Also, what if the disk throws an error in the middle? Is there a backup copy to restore (and yes, I know that a disk can throw an error on that)?

I'm OK with slower. I'm just trying to understand the protection envelope before I give up my logic and trust exiftool's :-)