* test/lisp/mail/flow-fill-tests.el
(fill-flow-tests-fill-flowed-decode): Remove debug message.
(fill-flow-tests-fill-flowed-encode): Actually test function
`fill-flowed-encode', which requires `use-hard-newline' to be
non-nil. Also adjust test input to check behavior of the
function under different cases. (Bug#72870)
* lisp/mail/flow-fill.el (fill-flowed): Loop until all flowed lines
are collected.
* test/lisp/mail/flow-fill-tests.el
(fill-flow-tests-fill-flowed-decode): Also test for multiple
flowed lines (bug#42855).
* lisp/mail/flow-fill.el (fill-flowed): Reimplement the function
to respect space-stuffing (bug#17190).
* test/lisp/mail/flow-fill-tests.el
(fill-flow-tests-fill-flowed-stuffed): New test.
(fill-flow-tests-fill-flowed-decode): Rename the test so that it
actually runs.