Fix title extraction algorithm

_plugins/social_images.rb

@@ -29,8 +29,8 @@ def generate(site)
         Jekyll.logger.info('Skipping social image generation')
         return
       end
-      generate_images(Dir.glob(File.join(site.source, '_guides', '*.adoc')), site)
       generate_images(Dir.glob(File.join(site.source, '_posts', '*.adoc')), site)
+      generate_images(Dir.glob(File.join(site.source, '_guides', '*.adoc')), site)
     end
 
     def split_text_into_lines(text)
@@ -105,7 +105,12 @@ def generate_svg_string(title)
       idx = 90
       font_size = 30
       tspan_elements = ''
-      split_text_into_lines(title.gsub('&', '&')).each_with_index do |line, index|
+      # Sanitize title
+      title = title.gsub(/&/, '&')
+      title = title.gsub(/</, '&lt;')
+      title = title.gsub(/>/, '&gt;')
+
+      split_text_into_lines(title).each_with_index do |line, index|
         tspan_elements += "<tspan x='50%' y='#{idx}'>#{line}</tspan>"
         idx += font_size + 10
       end
@@ -122,16 +127,27 @@ def generate_svg_string(title)
     end
 
     def extract_title(adoc_file)
-      title = ''
-      File.open(adoc_file, 'r') do |file|
-        file.each_line do |line|
-          if line.start_with? '='
-            title = line[2..].strip
+      line_nr = 0
+      File.readlines(adoc_file).each do |line|
+        if line_nr == 0
+          # If line does not start with --- break
+          unless line.strip.start_with?('---')
             break
           end
         end
+        if line_nr > 0 && line.strip.start_with?('---')
+          break;
+        end
+        if line.strip.start_with?('title:')
+          title = line.strip.sub('title:', '').strip
+          # Remove quotes
+          title = title.gsub(/\A[\"']|[\"']\z/, '')
+          return title
+        end
+        line_nr += 1
       end
-      title
+      doc = Asciidoctor.load_file(adoc_file, header_only: true, logger: NullLogger.new)
+      doc.doctitle
     end
   end
 end