mv: -i -n should have different behavior than -n -i if target exists

[cakebaker]

When using both -i/--interactive and -n/--no-clobber, GNU mv only uses the argument that comes last if the target exists.

$ touch aa.txt
$ touch bb.txt
$ mv aa.txt bb.txt -i -n  # ignores -i
mv: not replacing 'bb.txt'
$ mv aa.txt bb.txt -n -i  # ignores -n
mv: overwrite 'bb.txt'?

With uutils mv, -n/--no-clobber "wins" in both cases:

$ touch aa.txt
$ touch bb.txt
$ cargo run mv aa.txt bb.txt -i -n
mv: not replacing 'bb.txt'
$ cargo run mv aa.txt bb.txt -n -i
mv: not replacing 'bb.txt'

[shinhs0506]

Looks like we just default to -n

coreutils/src/uu/mv/src/mv.rs

Lines 219 to 232 in a97199f

	fn determine_overwrite_mode(matches: &ArgMatches) -> OverwriteMode {
	// This does not exactly match the GNU implementation:
	// The GNU mv defaults to Force, but if more than one of the
	// overwrite options are supplied, only the last takes effect.
	// To default to no-clobber in that situation seems safer:
	//
	if matches.get_flag(OPT_NO_CLOBBER) {
	OverwriteMode::NoClobber
	} else if matches.get_flag(OPT_INTERACTIVE) {
	OverwriteMode::Interactive
	} else {
	OverwriteMode::Force
	}
	}