reconnect after fork

Changes

@@ -1,5 +1,6 @@
 
 2.02  2015-03-30
+  - Improved fork-safety of Mojo::Pg::PubSub.
 
 2.01  2015-03-25
   - Fixed bug where Perl would close the DBD::Pg file descriptor unexpectedly.

lib/Mojo/Pg/PubSub.pm

@@ -25,6 +25,10 @@ sub unlisten {
 sub _db {
   my $self = shift;
 
+  # Fork-safety
+  $self->{db} and delete($self->{db})->disconnect
+    unless ($self->{pid} //= $$) eq $$;
+
   return $self->{db} if $self->{db};
 
   my $db = $self->{db} = $self->pg->db;

t/pubsub.t

@@ -86,4 +86,23 @@ is_deeply \@test, [], 'no messages';
   is_deeply \@test, ['works too'], 'right messages';
 };
 
+# Fork-safety
+$pg = Mojo::Pg->new($ENV{TEST_ONLINE});
+@dbhs = @test = ();
+$pg->pubsub->on(reconnect => sub { push @dbhs, pop->dbh });
+$pg->pubsub->listen(pstest => sub { push @test, pop });
+ok $dbhs[0], 'database handle';
+ok $dbhs[0]->ping, 'connected';
+$pg->pubsub->notify(pstest => 'first');
+is_deeply \@test, ['first'], 'right messages';
+{
+  local $$ = -23;
+  $pg->pubsub->notify(pstest => 'second');
+  ok $dbhs[1], 'database handle';
+  ok $dbhs[1]->ping, 'connected';
+  isnt $dbhs[0], $dbhs[1], 'different database handles';
+  ok !$dbhs[0]->ping, 'not connected';
+  is_deeply \@test, ['first', 'second'], 'right messages';
+};
+
 done_testing();