PR174581: Clarify recv functions can return 0 if no messages are waiting and the peer has closed the connection.

[felix.the.red_gmail.com]

Summary

Change the RETURN VALUES section to indicate 0 is a possible return value.

[ziaee]

This section looks great! Would you be willing to mark up those return values as defined variables? I'll Cc some guardians of the syscalls.

[ziaee]

May I commit this?

[mhorne]

In D48955#1116722, @ziaee wrote:

May I commit this?

Yes, just be sure to set the author data correctly in git:

git commit --amend --author="Felix Johnson <[e-mail]>"

And with the trailers:

PR:          174581
Reviewed by: jhb, ziaee
Approved by: mhorne (mentor)

And I believe the title needs to be shortened/summarized.

[des]

I realize that this has already been committed but I noticed some style issues. We have a rule to never start a sentence with .Fn or .Nm, but use “The ... function” or “The ... command” to ensure the sentence starts with a capitalized word. The suggested edit is the minimum change to ensure that we don't start a sentence with .Fn recvmmsg. Adding “the ... function[s]” both there and in the previous clause is optional but recommended for consistency.

lib/libsys/recv.2

324

[ziaee]

Sounds great, thanks Des! Posted at https://reviews.freebsd.org/D48995