3 files changed, 40 insertions, 11 deletions

diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 4a43185c..c8592dc0 100644
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -160,6 +160,7 @@ sub cmd_idle ($$) {
         # IDLE seems allowed by dovecot w/o a mailbox selected *shrug*
         my $ibx = $self->{ibx} or return "$tag BAD no mailbox selected\r\n";
         $ibx->subscribe_unlock(fileno($self->{sock}), $self);
+        $self->{imapd}->idler_start;
         $self->{-idle_tag} = $tag;
         $self->{-idle_max} = $ibx->mm->max // 0;
         "+ idling\r\n"
diff --git a/lib/PublicInbox/IMAPD.pm b/lib/PublicInbox/IMAPD.pm
index 1922c160..05aa30e4 100644
--- a/lib/PublicInbox/IMAPD.pm
+++ b/lib/PublicInbox/IMAPD.pm
@@ -16,18 +16,22 @@ sub new {
                 out => \*STDOUT,
                 grouplist => [],
                 # accept_tls => { SSL_server => 1, ..., SSL_reuse_ctx => ... }
+                # pi_config => PublicInbox::Config
                 # idler => PublicInbox::InboxIdle
         }, $class;
 }
 
 sub refresh_groups {
         my ($self) = @_;
-        if (my $old_idler = delete $self->{idler}) {
-                $old_idler->close; # PublicInbox::DS::close
-        }
-        my $pi_config = PublicInbox::Config->new;
-        $self->{idler} = PublicInbox::InboxIdle->new($pi_config);
+        my $pi_config = $self->{pi_config} = PublicInbox::Config->new;
         $self->SUPER::refresh_groups($pi_config);
+        if (my $idler = $self->{idler}) {
+                $idler->refresh($pi_config);
+        }
+}
+
+sub idler_start {
+        $_[0]->{idler} //= PublicInbox::InboxIdle->new($_[0]->{pi_config});
 }
 
 1;
diff --git a/lib/PublicInbox/InboxIdle.pm b/lib/PublicInbox/InboxIdle.pm
index 095a801c..c19b8d18 100644
--- a/lib/PublicInbox/InboxIdle.pm
+++ b/lib/PublicInbox/InboxIdle.pm
@@ -4,7 +4,8 @@
 package PublicInbox::InboxIdle;
 use strict;
 use base qw(PublicInbox::DS);
-use fields qw(pi_config inot);
+use fields qw(pi_config inot pathmap);
+use Cwd qw(abs_path);
 use Symbol qw(gensym);
 use PublicInbox::Syscall qw(EPOLLIN EPOLLET);
 my $IN_CLOSE = 0x08 | 0x10; # match Linux inotify
@@ -19,13 +20,35 @@ if ($^O eq 'linux' && eval { require Linux::Inotify2; 1 }) {
 require PublicInbox::In2Tie if $ino_cls;
 
 sub in2_arm ($$) { # PublicInbox::Config::each_inbox callback
-        my ($ibx, $inot) = @_;
-        my $path = "$ibx->{inboxdir}/";
-        $path .= $ibx->version >= 2 ? 'inbox.lock' : 'ssoma.lock';
-        $inot->watch($path, $IN_CLOSE, sub { $ibx->on_unlock });
+        my ($ibx, $self) = @_;
+        my $dir = abs_path($ibx->{inboxdir});
+        if (!defined($dir)) {
+                warn "W: $ibx->{inboxdir} not watched: $!\n";
+                return;
+        }
+        my $inot = $self->{inot};
+        my $cur = $self->{pathmap}->{$dir} //= [];
+
+        # transfer old subscriptions to the current inbox, cancel the old watch
+        if (my $old_ibx = $cur->[0]) {
+                $ibx->{unlock_subs} and
+                        die "BUG: $dir->{unlock_subs} should not exist";
+                $ibx->{unlock_subs} = $old_ibx->{unlock_subs};
+                $cur->[1]->cancel;
+        }
+        $cur->[0] = $ibx;
+
+        my $lock = "$dir/".($ibx->version >= 2 ? 'inbox.lock' : 'ssoma.lock');
+        $cur->[1] = $inot->watch($lock, $IN_CLOSE, sub { $ibx->on_unlock });
+
         # TODO: detect deleted packs (and possibly other files)
 }
 
+sub refresh {
+        my ($self, $pi_config) = @_;
+        $pi_config->each_inbox(\&in2_arm, $self);
+}
+
 sub new {
         my ($class, $pi_config) = @_;
         my $self = fields::new($class);
@@ -42,7 +65,8 @@ sub new {
                 $inot = PublicInbox::FakeInotify->new;
         }
         $self->{inot} = $inot;
-        $pi_config->each_inbox(\&in2_arm, $inot);
+        $self->{pathmap} = {}; # inboxdir => [ ibx, watch1, watch2, watch3...]
+        refresh($self, $pi_config);
         $self;
 }