Added support for poorly formed internal urls.

Cases added: [[ url ]], [[ url | label ]], [[ url label ]]
Tests added and passing

lib/marker/language.treetop

@@ -382,14 +382,23 @@ module Marker
     #   [ external [[internal]] ]
     # MediaWiki: <a href="external"></a><a href="internal">internal</a>
     # Marker:  <a href="external">[[internal]]</a>
+    #
+    # also use this rule to match bad internal link syntax [[ url | label ]]
+    # because the rendering rules are the same
     rule external_link
-      external_link_start ws t:url rws l:external_link_enclosed_text ws external_link_end <ExternalLink>
-      /
-      external_link_start ws t:url ws external_link_end <ExternalLink>
-      /
+#      external_link_start ws t:url rws l:external_link_enclosed_text ws external_link_end <ExternalLink>
+#      /
+#      external_link_start ws t:url ws external_link_end <ExternalLink>
+#      /
       external_link_start ws t:implicit_url rws l:external_link_enclosed_text ws external_link_end <ExternalLink>
       /
       external_link_start ws t:implicit_url ws external_link_end <ExternalLink>
+      /
+      internal_link_start ws t:implicit_url rws l:internal_link_enclosed_text ws internal_link_end <ExternalLink>
+      /
+      internal_link_start ws t:implicit_url ws arg_delimiter ws l:internal_link_enclosed_text ws internal_link_end <ExternalLink>
+      /
+      internal_link_start ws t:implicit_url ws internal_link_end <ExternalLink>
     end
 
     rule external_link_enclosed_text

test/links_test.rb

@@ -34,6 +34,20 @@ def test_internal_link_with_sanitization
     assert_match("<a href='/Example page'>Example page</a>", markup.to_html)
   end
 
+  def test_internal_with_url
+    text = "[[http://www.example.com]]"
+    markup = Marker.parse text
+    assert_match("<p><a href='http://www.example.com'>[1]</a></p>\n<ol><li><a href='http://www.example.com'>http://www.example.com</a></li></ol>", markup.to_html)
+
+    text = "[[http://www.example.com|Example page]]"
+    markup = Marker.parse text
+    assert_match("<a href='http://www.example.com'>Example page</a>", markup.to_html)
+
+    text = "[[http://www.example.com Example page]]"
+    markup = Marker.parse text
+    assert_match("<a href='http://www.example.com'>Example page</a>", markup.to_html)
+  end
+
   def test_external_link_with_alias
     text = "[http://www.example.com Example link]"
     markup = Marker.parse text