http: document event_write usage

It may not be obvious where we are when we enter the event_write
callback.  Hopefully this clarifies things.

1 files changed, 2 insertions, 3 deletions

diff --git a/lib/PublicInbox/HTTP.pm b/lib/PublicInbox/HTTP.pm
index 4d771f2b..a472388d 100644
--- a/lib/PublicInbox/HTTP.pm
+++ b/lib/PublicInbox/HTTP.pm
@@ -201,10 +201,9 @@ sub event_write {
         # only continue watching for readability when we are done writing:
         return if $self->write(undef) != 1;
 
-        if ($self->{rbuf} eq '') {
+        if ($self->{rbuf} eq '') { # wait for next request
                 $self->watch_read(1);
-        } else {
-                # avoid recursion for pipelined requests
+        } else { # avoid recursion for pipelined requests
                 Danga::Socket->AddTimer(0, sub { rbuf_process($self) });
         }
 }