fgets(3) man page clarity on when NUL appended

["J. Lewis Muir" <jlmuir%imca-cat.org@localhost>]

Hi!

I was using

  https://man.netbsd.org/fgets.3

as a reference for the fgets() function for an application I'm writing,
and when testing my application, I was surprised to discover that if
fgets() reads EOF right away, it does not append a NUL character.  (I
confirmed this behavior on NetBSD 9.3 release.)  I think it would be
helpful to clarify this in the man page.  Would a developer be willing
to do this?  If so, I'm happy to send a patch if that would be helpful,
or if it's easier for a developer to just do it, that would be great
too!  Suggested wording is below.

Here's what the NetBSD man page says at the end of the first paragraph
in the Description section:

  Reading stops when a newline character is found, at end-of-file or
  error.  The newline, if any, is retained, and a `\0' character is
  appended to end the string.

I interpreted that to mean that it always appends a NUL character
regardless of why it stopped reading.  But that's not what it does.

The FreeBSD fgets(3) man page

  https://man.freebsd.org/cgi/man.cgi?query=fgets&sektion=3

says the following, which I think is clearer and would have likely
helped me avoid my initial misunderstanding:

  Reading stops when a newline character is found, at end-of-file or
  error.  The newline, if any, is retained.  If any characters are read
  and there is no error, a `\0' character is appended to end the string.

I like this wording better because it says that the NUL character is
appended only if any characters are read and there is no error.

Thanks!

Lewis