test/automated/decoder-tests.el (ert-test-decoder-prefer-utf-8):
Force Unix EOLs by using 'utf-8-unix', since the default of
'utf-8' is system-dependent, while the test expects to see Unix
EOLs.
(decoder-tests-ao-gen-file): Renamed from decoder-tests-filename.
Callers changed.
(decoder-tests-filename): New function.
(decoder-tests-prefer-utf-8-read)
(decoder-tests-prefer-utf-8-write): New function.
(ert-test-decoder-prefer-utf-8): New test.