>> All I know is whether a particular file is in the input diff set.
>
>What makes you assume that patch must create copies of all
>files it is trying to modify, even copies that aren't needed?
>I could make the argument that patch shouldn't use more
>disk space than necessary.
You would be wrong, because patch already creates exactly one additional
copy of the file (*.orig). Formerly, foo.orig was always the original
directory entry and foo was always a newly created file. With the
behavior I argue to be a bug, if all hunks for a file fail, then foo is
the original directory entry and foo.orig is a newly created file.
Either way, patch uses the same amount of disk space.
--Andrew Church
http://achurch.org/