lei: support reading MH for convert+import+index

The MH format is widely-supported and used by various MUAs such
as mutt and sylpheed, and a MH-like format is used by mlmmj for
archives, as well.  Locking implementations for writes are
inconsistent, so this commit doesn't support writes, yet.

inotify|EVFILT_VNODE watches aren't supported, yet, but that'll
have to come since MH allows packing unused integers and
renaming files.

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/PublicInbox/LeiToMail.pm b/lib/PublicInbox/LeiToMail.pm
index 071ba113..de75e99e 100644
--- a/lib/PublicInbox/LeiToMail.pm
+++ b/lib/PublicInbox/LeiToMail.pm
@@ -400,6 +400,11 @@ sub new {
                                 "$dst exists and is not a directory\n";
                 $lei->{ovv}->{dst} = $dst .= '/' if substr($dst, -1) ne '/';
                 $lei->{opt}->{save} //= \1 if $lei->{cmd} eq 'q';
+        } elsif ($fmt eq 'mh') {
+                -e $dst && !-d _ and die
+                                "$dst exists and is not a directory\n";
+                $lei->{ovv}->{dst} = $dst .= '/' if substr($dst, -1) ne '/';
+                $lei->{opt}->{save} //= \1 if $lei->{cmd} eq 'q';
         } elsif (substr($fmt, 0, 4) eq 'mbox') {
                 require PublicInbox::MboxReader;
                 $self->can("eml2$fmt") or die "bad mbox format: $fmt\n";