- let mut iter = os_str_as_u8_slice(file).rsplitn(2, |b| *b == b'.');
- let after = iter.next();
- let before = iter.next();
- if before == Some(b"") {
- (Some(file), None)
- } else {
- (before.map(|s| u8_slice_as_os_str(s)), after.map(|s| u8_slice_as_os_str(s)))
- }
+ // The unsafety here stems from converting between &OsStr and &[u8]
+ // and back. This is safe to do because (1) we only look at ASCII
+ // contents of the encoding and (2) new &OsStr values are produced
+ // only from ASCII-bounded slices of existing &OsStr values.
+ let mut iter = os_str_as_u8_slice(file).rsplitn(2, |b| *b == b'.');
+ let after = iter.next();
+ let before = iter.next();
+ if before == Some(b"") {
+ (Some(file), None)
+ } else {
+ unsafe { (before.map(|s| u8_slice_as_os_str(s)), after.map(|s| u8_slice_as_os_str(s))) }