[PATCH 16/19] lei q: SIGWINCH process group with the terminal

[Eric Wong <e@80x24.org>]

While using utime on the destination Maildir is enough for mutt
to eventually notice new mail, "eventually" isn't good enough.

Send a SIGWINCH to wake mutt (and likely other MUAs)
immediately.  This is more portable than relying on MUAs to
support inotify or EVFILT_VNODE.
---
 lib/PublicInbox/LEI.pm        | 11 +++++++++++
 lib/PublicInbox/LeiXSearch.pm |  7 ++++++-
 script/lei                    |  8 +++++---
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index e52154e5..00affe82 100644
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -746,6 +746,17 @@ sub start_mua {
 	}
 }
 
+sub poke_mua { # forces terminal MUAs to wake up and hopefully notice new mail
+	my ($self) = @_;
+	return unless $self->{opt}->{mua} && -t $self->{1};
+	# hit the process group that started the MUA
+	if (my $s = $self->{sock}) {
+		send($s, '-WINCH', MSG_EOR);
+	} elsif ($self->{oneshot}) {
+		kill('-WINCH', $$);
+	}
+}
+
 # caller needs to "-t $self->{1}" to check if tty
 sub start_pager {
 	my ($self) = @_;
diff --git a/lib/PublicInbox/LeiXSearch.pm b/lib/PublicInbox/LeiXSearch.pm
index 0e99e4b4..a7668a17 100644
--- a/lib/PublicInbox/LeiXSearch.pm
+++ b/lib/PublicInbox/LeiXSearch.pm
@@ -321,7 +321,12 @@ Error closing $lei->{ovv}->{dst}: $!
 			}
 			$lei->{1} = $out;
 		}
-		$l2m->lock_free ? $l2m->poke_dst : $lei->start_mua;
+		if ($l2m->lock_free) {
+			$l2m->poke_dst;
+			$lei->poke_mua;
+		} else { # mbox users
+			$lei->start_mua;
+		}
 	}
 	$lei->{-progress} and
 		$lei->err('# ', $lei->{-mset_total} // 0, " matches");
diff --git a/script/lei b/script/lei
index b7f21f14..0b0e2976 100755
--- a/script/lei
+++ b/script/lei
@@ -105,13 +105,15 @@ Falling back to (slow) one-shot mode
 			die "recvmsg: $!";
 		}
 		last if $buf eq '';
-		if ($buf =~ /\Ax_it ([0-9]+)\z/) {
+		if ($buf =~ /\Aexec (.+)\z/) {
+			$exec_cmd->(\@fds, split(/\0/, $1));
+		} elsif ($buf eq '-WINCH') {
+			kill($buf, $$); # for MUA
+		} elsif ($buf =~ /\Ax_it ([0-9]+)\z/) {
 			$x_it_code = $1 + 0;
 			last;
 		} elsif ($buf =~ /\Achild_error ([0-9]+)\z/) {
 			$x_it_code = $1 + 0;
-		} elsif ($buf =~ /\Aexec (.+)\z/) {
-			$exec_cmd->(\@fds, split(/\0/, $1));
 		} else {
 			$sigchld->();
 			die $buf;