+sub fp_done {
+ my ($self, $go_fetch) = @_;
+ my $fh = delete $self->{-show_ref} // die 'BUG: no show-ref output';
+ seek($fh, SEEK_SET, 0) or die "seek(show_ref): $!";
+ $self->{-ent} // die 'BUG: no -ent';
+ my $A = $self->{-ent}->{fingerprint} // die 'BUG: no fingerprint';
+ my $B = sha1_hex(do { local $/; <$fh> } // die("read(show_ref): $!"));
+ return if $A ne $B; # $go_fetch->DESTROY fires
+ $go_fetch->cancel;
+ $self->{lei}->qerr("# $self->{-key} up-to-date");
+}
+
+sub cmp_fp_fetch {
+ my ($self, $go_fetch) = @_;
+ # $go_fetch is either resume_fetch or fgrp_enqueue
+ my $new = $self->{-ent}->{fingerprint} // die 'BUG: no fingerprint';
+ my $key = $self->{-key} // die 'BUG: no -key';
+ if (my $cur_ent = $self->{-local_manifest}->{$key}) {
+ # runs go_fetch->DESTROY run if eq
+ return $go_fetch->cancel if $cur_ent->{fingerprint} eq $new;
+ }
+ my $dst = $self->{cur_dst} // $self->{dst};
+ my $cmd = ['git', "--git-dir=$dst", 'show-ref'];
+ my $opt = { 2 => $self->{lei}->{2} };
+ open($opt->{1}, '+>', undef) or die "open(tmp): $!";
+ $self->{-show_ref} = $opt->{1};
+ my $done = PublicInbox::OnDestroy->new($$, \&fp_done, $self, $go_fetch);
+ start_cmd($self, $cmd, $opt, $done);
+}
+
+sub resume_fetch_maybe {
+ my ($self, $uri, $fini) = @_;
+ my $go_fetch = PublicInbox::OnDestroy->new($$, \&resume_fetch, @_);
+ cmp_fp_fetch($self, $go_fetch) if $self->{-ent} &&
+ defined($self->{-ent}->{fingerprint});
+}
+