imap: avoid raising exception if client disconnects

This ought to save a few cycles if a client disconnects while
in the middle of a (UID) FETCH.  This avoids:

  Can't call method "git" on an undefined value at .../PublicInbox/IMAP.pm

errors in stderr.

(cherry picked from commit 34880bc83077eac5739deca69f66df7685965064)

diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 47c08aea0300583d10071f43f3715a8f7b4de2bd..d93792acf7ae94406d54999ecc1cf11c01510713 100644 (file)
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -615,18 +615,19 @@ sub fetch_run_ops {
 sub fetch_blob_cb { # called by git->cat_async via git_async_cat
        my ($bref, $oid, $type, $size, $fetch_arg) = @_;
        my ($self, undef, $msgs, $range_info, $ops, $partial) = @$fetch_arg;
 sub fetch_blob_cb { # called by git->cat_async via git_async_cat
        my ($bref, $oid, $type, $size, $fetch_arg) = @_;
        my ($self, undef, $msgs, $range_info, $ops, $partial) = @$fetch_arg;

+       my $ibx = $self->{ibx} or return $self->close; # client disconnected

        my $smsg = shift @$msgs or die 'BUG: no smsg';
        if (!defined($oid)) {
                # it's possible to have TOCTOU if an admin runs
                # public-inbox-(edit|purge), just move onto the next message
        my $smsg = shift @$msgs or die 'BUG: no smsg';
        if (!defined($oid)) {
                # it's possible to have TOCTOU if an admin runs
                # public-inbox-(edit|purge), just move onto the next message

-               warn "E: $smsg->{blob} missing in $self->{ibx}->{inboxdir}\n";
+               warn "E: $smsg->{blob} missing in $ibx->{inboxdir}\n";

                return requeue_once($self);
        } else {
                $smsg->{blob} eq $oid or die "BUG: $smsg->{blob} != $oid";
        }
        my $pre;
        if (!$self->{wbuf} && (my $nxt = $msgs->[0])) {
                return requeue_once($self);
        } else {
                $smsg->{blob} eq $oid or die "BUG: $smsg->{blob} != $oid";
        }
        my $pre;
        if (!$self->{wbuf} && (my $nxt = $msgs->[0])) {

-               $pre = $self->{ibx}->git->async_prefetch($nxt->{blob},
+               $pre = $ibx->git->async_prefetch($nxt->{blob},

                                                \&fetch_blob_cb, $fetch_arg);
        }
        fetch_run_ops($self, $smsg, $bref, $ops, $partial);
                                                \&fetch_blob_cb, $fetch_arg);
        }
        fetch_run_ops($self, $smsg, $bref, $ops, $partial);