(Patch by Ronald Oussoren)

It was correct in the original patch and I foobared it
when I restructured part of the code.

The new code correctly handles historic changes in UTC offsets.
A test for this should follow.

Original patch by Alexander Belopolsky.

had a coefficient with MAX_PREC=425000000 digits and a negative exponent.
Increasing the context limits above the official values fixes the issue
and is safe (in this case!).

   required for a corner case in dec_hash() in the following commit and also
   usually faster. dec_hash() needs some extra precision above MPD_MAX_PREC,
   and _mpd_base_ndivmod() is not audited for that.

2) Use _mpd_basemul() if the length of the smaller operand is less than
   or equal to 256. While this is technically an optimization, it is
   required for *testing* corner cases in dec_hash() in reasonable time.

This is due to an off-by-one error: the allocated buffer didn't have room for a NUL
character at the end of the mbstowcs result.

(merge with 3.2)

This is due to an off-by-one error: the allocated buffer didn't have room for a NUL
character at the end of the mbstowcs result.

This is necessary for ZFS systems, which don't support UF_IMMUTABLE.

(Note: this commit is a manual merge of 78699:019a2390b014 as both
_test_chflags_regular_file and test_lchflags_symlink differ between
3.2 and default.)

This is necessary for ZFS systems, which don't support UF_IMMUTABLE.

Patch by Ethan Furman.

Patch by Ethan Furman.

Suggestion and patch by Mike Hoy.

Suggestion and patch by Mike Hoy.

Patch by Robin Schreiber.

Patch by Robin Schreiber.