+#!perl -w
+# Copyright (C) 2021 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+use strict; use v5.10.1; use PublicInbox::TestCommon;
+use PublicInbox::Git;
+use PublicInbox::Eml;
+use PublicInbox::MsgIter qw(msg_part_text);
+use PublicInbox::LeiToMail;
+my $eml2mboxcl2 = PublicInbox::LeiToMail->can('eml2mboxcl2');
+my $git_dir = $ENV{GIANT_GIT_DIR};
+plan 'skip_all' => "GIANT_GIT_DIR not defined for $0" unless defined($git_dir);
+use Data::Dumper;
+$Data::Dumper::Useqq = 1;
+my $mboxfh;
+if (my $out = $ENV{DEBUG_MBOXCL2}) {
+ BAIL_OUT("$out exists") if -s $out;
+ open $mboxfh, '>', $out or BAIL_OUT "open $out: $!";
+} else {
+ diag "DEBUG_MBOXCL2 unset, not saving debug output";
+}
+
+my $git = PublicInbox::Git->new($git_dir);
+my @cat = qw(cat-file --buffer --batch-check --batch-all-objects);
+if (require_git(2.19, 1)) {
+ push @cat, '--unordered';
+} else {
+ warn "git <2.19, cat-file lacks --unordered, locality suffers\n";
+}
+my ($errs, $ok, $tot);
+$errs = $ok = $tot = 0;
+my $ep = sub { # eml->each_part callback
+ my ($part, $level, @ex) = @{$_[0]};
+ ++$tot;
+ my $ct = $part->content_type // return;
+ $ct =~ m!\bapplication/octet-stream\b!i or return;
+ my ($s, $err) = msg_part_text($part, $ct);
+ if (defined $s) {
+ ++$ok;
+ } else {
+ warn "binary $err\n";
+ ++$errs;
+ my $x = eval { $part->body };
+ if ($@) {
+ warn "decode totally failed: $@";
+ } else {
+ my ($bad) = ($x =~ m/([\p{XPosixPrint}\s]{0,10}
+ [^\p{XPosixPrint}\s]+
+ [\p{XPosixPrint}\s]{0,10})/sx);
+ warn Dumper([$bad]);
+ }
+
+ push @{$_[1]}, $err; # $fail
+ }
+};
+
+my $cb = sub {
+ my ($bref, $oid) = @_;
+ my $eml = PublicInbox::Eml->new($bref);
+ local $SIG{__WARN__} = sub { diag("$oid ", @_) };
+ $eml->each_part($ep, my $fail = []);
+ if (@$fail && $mboxfh) {
+ diag "@$fail";
+ print $mboxfh ${$eml2mboxcl2->($eml, { blob => $oid })} or
+ BAIL_OUT "print: $!";
+ }
+};
+my $cat = $git->popen(@cat);
+while (<$cat>) {
+ my ($oid, $type, $size) = split(/ /);
+ $git->cat_async($oid, $cb) if $size && $type eq 'blob';
+}
+$git->cat_async_wait;
+note "$errs errors";
+note "$ok/$tot messages had text as application/octet-stream";
+ok 1;
+
+done_testing;