From 60bddabfdddae797faddb681681fafcd4c91a323 Mon Sep 17 00:00:00 2001
From: Mischa Poslawsky <wormy@shiar.org>
Date: Mon, 26 Oct 2020 20:42:25 +0100
Subject: [PATCH 1/1] parse-wormedit: warn about missing level data for render

Catch resulting errors after empty input such as with wormy003.lvl
missing singleplayer levels.
---
 lib/Games/Wormy/Render.pm | 3 ++-
 parse-wormedit            | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/Games/Wormy/Render.pm b/lib/Games/Wormy/Render.pm
index 5a86452..2c83536 100644
--- a/lib/Games/Wormy/Render.pm
+++ b/lib/Games/Wormy/Render.pm
@@ -8,7 +8,7 @@ use experimental 'switch';
 use Imager;
 use List::Util qw(sum max);
 
-our $VERSION = '1.00';
+our $VERSION = '1.01';
 
 our %COL = (
 	bg     => Imager::Color->new(255, 255, 255),
@@ -24,6 +24,7 @@ our %COL = (
 
 sub level {
 	my ($self, $level) = @_;
+	$level or return;
 
 	my $field = Imager->new(xsize => $level->{width}, ysize => $level->{height});
 	$field->box(filled => 1, color => $COL{bg});
diff --git a/parse-wormedit b/parse-wormedit
index 0c94994..ffd68ef 100755
--- a/parse-wormedit
+++ b/parse-wormedit
@@ -77,10 +77,11 @@ if (defined $opt{render}) {
 		# default to all singleplayer levels
 		@request = 0 .. $data->{levelcount}->{single} - 1;
 	}
+	@request or die "no levels found or specified\n";
 
 	my $img = Games::Wormy::Render->composite(
 		map { $data->{levels}->[$_] } @request
-	);
+	) or die "empty result for levels\n";
 	$img->write(
 		$opt{output} ? (file => $opt{output}) : (fh => \*STDOUT, type => 'pnm')
 	) or die $img->errstr;
-- 
2.30.0