Fix #535 and add test

lib/gollum/markup.rb

@@ -122,7 +122,7 @@ module Gollum
         end
         node = Nokogiri::XML::Node.new('li', doc)
         # % -> %25 so anchors work on Firefox. See issue #475
-        node.add_child("<a href='##{id.gsub('%', '%25')}'>#{h.content}</a>")
+        node.add_child(%Q{<a href="##{id.gsub("%", "%25")}">#{h.content}</a>})
         tail.add_child(node)
       end
       toc = toc.to_xhtml if toc != nil

test/test_wiki.rb

@@ -142,6 +142,16 @@ context "Wiki TOC" do
     assert_equal '<h1>Bilbo<a class="anchor" id="Bilbo" href="#Bilbo"></a></h1>', page.formatted_data.gsub(/\n/,"")
     assert_equal %{<div class="toc"><div class="toc-title">Table of Contents</div><ul><li><a href="#Bilbo">Bilbo</a></li></ul></div>}, page.toc_data.gsub(/\n */,"")
   end
+
+  # Ensure ' creates valid links in TOC
+  # Incorrect: <a href=\"#a\" b=\"\">
+  #   Correct: <a href=\"#a'b\">
+  test "' in link" do
+    page = @wiki.preview_page("Test", "# a'b", :markdown)
+    assert_equal "# a'b", page.raw_data
+    assert_equal %q{<h1>a'b<a class="anchor" id="a'b" href="#a'b"></a></h1>}, page.formatted_data.gsub(/\n/,"")
+    assert_equal %{<div class=\"toc\"><div class=\"toc-title\">Table of Contents</div><ul><li><a href=\"#a'b\">a'b</a></li></ul></div>}, page.toc_data.gsub(/\n */,"")
+  end
 end
 
 context "Wiki page writing" do