revert: don't backup if no files reverted in interactive mode (issue4793)...
revert: don't backup if no files reverted in interactive mode (issue4793)
When reverting interactively, we always backup files before prompting the user
to find out if they actually want to revert them. This can create spurious
*.orig files if a user enters an interactive revert session and then doesn't
revert any files. Instead, we should only backup files that are actually being
touched.