1 files changed, 18 insertions, 0 deletions
diff --git a/lib/DBInfoscreen.pm b/lib/DBInfoscreen.pm
index 6be6e2c..1828737 100644
--- a/lib/DBInfoscreen.pm
+++ b/lib/DBInfoscreen.pm
@@ -26,6 +26,24 @@ my %default = (
 sub startup {
 	my ($self) = @_;
 
+	$self->hook(
+		before_dispatch => sub {
+			my ($self) = @_;
+
+           # The "theme" cookie is set client-side if the theme we delivered was
+           # changed by dark mode detection or by using the theme switcher. It's
+           # not part of Mojolicious' session data (and can't be, due to
+           # signing and HTTPOnly), so we need to add it here.
+
+			for my $cookie ( @{ $self->req->cookies } ) {
+				if ( $cookie->name eq 'theme' ) {
+					$self->session( theme => $cookie->value );
+					return;
+				}
+			}
+		}
+	);
+
 	$self->attr(
 		cache_hafas => sub {
 			my ($self) = @_;