bug#81225: pr: +0 is interpreted as file name

Hi,

I noticed that pr interprets +0 as a file name and not as +FIRST_PAGE.
And so a "no such file" error is shown whereas --pages=3D0 shows an
"invalid page range" error.

$ echo "foo" > foo
$ pr +0 foo
pr: +0: No such file or directory
[snipped pr output of the "foo" file]
$ pr --pages=3D0 foo
pr: invalid page range =E2=80=980=E2=80=99

I'm using coreutils 9.11.

Regards,
Daniel