From 46dd035ae0c6bfa4cd2b123e139db9fe04a10721 Mon Sep 17 00:00:00 2001
From: Aaron Sumner <asumner@mac.com>
Date: Sun, 22 Jul 2018 19:51:57 -0700
Subject: [PATCH] Make tags metadata optional per page

After upgrading Jekyll from 1.1.2j to 3.8.3 and jekyll-tagging from 1.0.1 to
1.1.0, having pages with no tags metadata causes builds to fail:

	$ jekyll build
	Configuration file: /Users/asumner/code/everyday-rails/_config.yml
    Source: /Users/asumner/code/everyday-rails
    Destination: ./_site
  Incremental build: disabled. Enable with --incremental
  Generating...
	Liquid Exception: undefined method `first' for nil:NilClass in /_layouts/post.html
	jekyll 3.8.3 | Error:  undefined method `first' for nil:NilClass

Fix by making the tags metadata optional per page. If the "tags" option isn't
found, don't try to make a tags list.
---
 lib/jekyll/tagging.rb | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/jekyll/tagging.rb b/lib/jekyll/tagging.rb
index 2637751..a6dc5fa 100644
--- a/lib/jekyll/tagging.rb
+++ b/lib/jekyll/tagging.rb
@@ -137,6 +137,7 @@ def tag_url(tag, type = :page, site = Tagger.site)
 
     def tags(obj)
       tags = obj['tags'].dup
+      return unless tags
       tags.map! { |t| t.first } if tags.first.is_a?(Array)
       tags.map! { |t| tag_link(t, tag_url(t), :rel => 'tag') if t.is_a?(String) }.compact!
       tags.join(', ')