lei: sort MH inputs sequentially by default

MH sequence numbers can be analogous to IMAP UIDs and NNTP
article numbers (or more like IMAP MSNs with clients which
pack).  In any case, sort then numerically by default to avoid
surprising users who treat NNTP spools and mlmmj archives as MH
folders.  This gives more coherent git history and resulting
NNTP/IMAP numbering when round-tripping MH -> v2 -> (NNTP|IMAP) -> MH

3 files changed, 13 insertions, 6 deletions

diff --git a/lib/PublicInbox/LeiInput.pm b/lib/PublicInbox/LeiInput.pm
index 947a7a79..d003d983 100644
--- a/lib/PublicInbox/LeiInput.pm
+++ b/lib/PublicInbox/LeiInput.pm
@@ -242,7 +242,7 @@ sub input_path_url {
                 }
         } elsif (-d _ && $ifmt eq 'mh') {
                 my $mhr = PublicInbox::MHreader->new($input.'/', $lei->{3});
-                $mhr->{sort} = $lei->{opt}->{sort};
+                $mhr->{sort} = $lei->{opt}->{sort} // [ 'sequence'];
                 $mhr->mh_each_eml($self->can('input_mh_cb'), $self, @args);
         } elsif (-d _ && $ifmt =~ /\A(?:v1|v2)\z/) {
                 my $ibx = PublicInbox::Inbox->new({inboxdir => $input});
diff --git a/lib/PublicInbox/MHreader.pm b/lib/PublicInbox/MHreader.pm
index 033aa740..3e7bbd5c 100644
--- a/lib/PublicInbox/MHreader.pm
+++ b/lib/PublicInbox/MHreader.pm
@@ -54,7 +54,8 @@ sub mh_each_file {
         opendir(my $dh, my $dir = $self->{dir});
         my $restore = PublicInbox::OnDestroy->new($$, \&chdir, $self->{cwdfh});
         chdir($dh);
-        if (defined(my $sort = $self->{sort})) {
+        my $sort = $self->{sort};
+        if (defined $sort && "@$sort" ne 'none') {
                 my @sort = map {
                         my @tmp = $_ eq '' ? ('sequence') : split(/[, ]/);
                         # sorting by name alphabetically makes no sense for MH:
diff --git a/t/mh_reader.t b/t/mh_reader.t
index 711fc8aa..c81df32e 100644
--- a/t/mh_reader.t
+++ b/t/mh_reader.t
@@ -7,6 +7,7 @@ use PublicInbox::IO qw(write_file);
 use PublicInbox::Lock;
 use PublicInbox::OnDestroy;
 use PublicInbox::Eml;
+use File::Path qw(remove_tree);
 use autodie;
 opendir my $cwdfh, '.';
 
@@ -103,12 +104,17 @@ test_lei(sub {
         like $lei_out, qr/^Subject: msg 4\nStatus: RO\n\n\n/ms,
                 "message retrieved after `lei index'";
 
+        lei_ok qw(convert -s none -f text), "mh:$for_sort", \'--sort=none';
+
         # ensure sort works for _input_ when output disallows sort
         my $v2out = "$ENV{HOME}/v2-out";
-        lei_ok qw(convert -s sequence), "mh:$for_sort", '-o', "v2:$v2out";
-        my $git = PublicInbox::Git->new("$v2out/git/0.git");
-        chomp(my @l = $git->qx(qw(log --pretty=oneline --format=%s)));
-        is_xdeeply \@l, [1, 22, 333], 'sequence order preserved for v2';
+        for my $sort (['--sort=sequence'], []) { # sequence is the default
+                lei_ok qw(convert), @$sort, "mh:$for_sort", '-o', "v2:$v2out";
+                my $g = PublicInbox::Git->new("$v2out/git/0.git");
+                chomp(my @l = $g->qx(qw(log --pretty=oneline --format=%s)));
+                is_xdeeply \@l, [1, 22, 333], 'sequence order preserved for v2';
+                File::Path::remove_tree $v2out;
+        }
 });
 
 done_testing;