nntp: do not drain rbuf if there is a command pending

Some clients pipeline requests aggressively (enough to match
LINE_MAX) and we should not read from the client socket until we
know there's no pending command in our read buffer.

Reported-and-tested-by: Sergey Organov <sorganov@gmail.com>

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 1e564634901ef69d8221d2ddbb19dc4d13cdb8b2..267fe4b93067189661204d408a842ea8f89dfb19 100644 (file)
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -949,10 +949,12 @@ sub event_write {
 sub event_read {
        my ($self) = @_;
        use constant LINE_MAX => 512; # RFC 977 section 2.3
-       my $r = 1;
 
-       my $buf = $self->read(LINE_MAX) or return $self->close;
-       $self->{rbuf} .= $$buf;
+       if (index($self->{rbuf}, "\n") < 0) {
+               my $buf = $self->read(LINE_MAX) or return $self->close;
+               $self->{rbuf} .= $$buf;
+       }
+       my $r = 1;
        while ($r > 0 && $self->{rbuf} =~ s/\A\s*([^\r\n]+)\r?\n//) {
                my $line = $1;
                return $self->close if $line =~ /[[:cntrl:]]/s;