Re: [PATCH] gcf2: improve error handling and do not ->fail on wbuf

[Eric Wong <e@80x24.org>]

Putting words together to write commit messages is hard
without enough sleep :<

Anyways, revised and pushed as
commit 8ba04f214bbadcbe106c94281a0c4c21dd50adb8

    gcf2: improve error handling and do not ->fail on wbuf
    
    For historical reasons, both Danga::Socket::write and
    PublicInbox::DS::write will return 0 when data is buffered;
    so Gcf2Client must not call ->fail when DS::write returns 0.
    
    We'll also improve robustness by recreating the entire
    Gcf2Client object if it does die for other reasons, instead of
    risking mismatched fields due to deferred close.
    
    We also need to ensure we only get one EPOLLERR wakeup and
    issue EPOLL_CTL_DEL if ->event_step is triggered by a dying
    Gcf2 process, so always register the FD with EPOLLONESHOT.