tweak code markup parser so that blocks without a language are just output in pre tags

lib/gollum/markup.rb

@@ -359,7 +359,7 @@ module Gollum
     #
     # Returns the placeholder'd String data.
     def extract_code(data)
-      data.gsub!(/^``` ?(.+?)\r?\n(.+?)\r?\n```\r?$/m) do
+      data.gsub!(/^``` ?([^\r\n]+)?\r?\n(.+?)\r?\n```\r?$/m) do
         id     = Digest::SHA1.hexdigest($2)
         cached = check_cache(:code, id)
         @codemap[id] = cached   ?
@@ -379,12 +379,15 @@ module Gollum
     def process_code(data)
       @codemap.each do |id, spec|
         formatted = spec[:output] || begin
-          lang = spec[:lang]
           code = spec[:code]
           if code.lines.all? { |line| line =~ /\A\r?\n\Z/ || line =~ /^(  |\t)/ }
             code.gsub!(/^(  |\t)/m, '')
           end
-          formatted = Gollum::Albino.new(code, lang).colorize
+          formatted = if lang = spec[:lang]
+            Gollum::Albino.new(code, lang).colorize
+          else
+            "<pre><code>#{CGI.escapeHTML(code)}</code></pre>"
+          end
           update_cache(:code, id, formatted)
           formatted
         end

test/test_markup.rb

@@ -394,8 +394,8 @@ context "Markup" do
   end
 
   test "code block with no lang" do
-    content = "a\n\n```\n\tls -al;\n\tbooya\n```\n\nb"
-    output = "<p>a</p>\n\n\n\n<p>b</p>"
+    content = "a\n\n```\n\tls -al;\n\t<booya>\n```\n\nb"
+    output = "<p>a</p>\n\n<pre><code>ls -al;\n&lt;booya&gt;</code></pre>\n\n<p>b</p>"
     compare(content, output)
   end