Log Message:
Update to 1.4.2:

* configure.in (VERSION): Bump to 1.4.2.
* NEWS: Describe 1.4.2's changes.

* src/m4.c (reference_error): Preserve errno, since M4ERROR
relies on this.
* src/builtin.c (m4_esyscmd): Clear errno before calling popen.
(m4_maketemp): Clear errno before calling mkstemp.
* src/path.c (path_search): Don't let "free" trash errno when
returning NULL.
* src/output.c (insert_file): Don't assume errno has a valid
value simply because fread returns zero.  This fixes a
portability bug reported by Marion Hakanson in
<http://lists.gnu.org/archive/html/bug-m4/2004-07/msg00029.html>.

Fixes PR pkg/27301.