bug#79497: fmt breaks lines when it does not need to

Hi Pádraig,

Thanks for answering. So, we have the multibyte problem and the
newline-included problem.

Pádraig Brady wrote:
> The code seems to follow the man page and includes the \n in the char count.
> Note fold -w does not count the newline which is what I'd expect.

I ran this test case with various 'fmt' implementations:

$ echo 'Hello world' | fmt -w 11
Hello
world
$ echo 'Hello world' | fmt -w 12
Hello world

The minimum -w option that produces a single line:

GNU              12
macOS, FreeBSD   11
NetBSD           11   (-g 10 -w 11)
OpenBSD          11
AIX, Solaris     12

So, the BSD implementations don't count the newline.

Bruno