ensures rel="nofollow" is added to all anchors if a page is retrieved with a SHA

lib/gollum.rb

@@ -59,6 +59,11 @@ module Gollum
       'img' => {'href' => ['http', 'https', :relative]}
     }
   }
+  HISTORY_SANITIZATION_OPTIONS = SANITIZATION_OPTIONS.merge(
+    :add_attributes => {
+      'a' => {'rel' => 'nofollow'}
+    }
+  )
 
   class Error < StandardError; end
   class DuplicatePageError < Error

lib/gollum/markup.rb

@@ -22,8 +22,14 @@ module Gollum
     # Render the content with Gollum wiki syntax on top of the file's own
     # markup language.
     #
+    # no_follow - Boolean that determines if rel="nofollow" is added to all
+    #             <a> tags.
+    #
     # Returns the formatted String content.
-    def render
+    def render(no_follow = false)
+      sanitize_options = no_follow   ? 
+        HISTORY_SANITIZATION_OPTIONS : 
+        SANITIZATION_OPTIONS
       data = extract_tex(@data)
       data = extract_code(data)
       data = extract_tags(data)
@@ -37,9 +43,9 @@ module Gollum
       end
       data = process_tags(data)
       data = process_code(data)
-      data = Sanitize.clean(data, SANITIZATION_OPTIONS)
+      data = Sanitize.clean(data, sanitize_options)
       data = process_tex(data)
-      data = data.gsub(/<p><\/p>/, '')
+      data.gsub!(/<p><\/p>/, '')
       data
     end
 
@@ -115,28 +121,33 @@ module Gollum
     # Process all tags from the tagmap and replace the placeholders with the
     # final markup.
     #
-    # data - The String data (with placeholders).
+    # data      - The String data (with placeholders).
+    # no_follow - Boolean that determines if rel="nofollow" is added to all
+    #             <a> tags.
     #
     # Returns the marked up String data.
-    def process_tags(data)
+    def process_tags(data, no_follow = false)
       @tagmap.each do |id, tag|
-        data.gsub!(id, process_tag(tag))
+        data.gsub!(id, process_tag(tag, no_follow))
       end
       data
     end
 
     # Process a single tag into its final HTML form.
     #
-    # tag - The String tag contents (the stuff inside the double brackets).
+    # tag       - The String tag contents (the stuff inside the double 
+    #             brackets).
+    # no_follow - Boolean that determines if rel="nofollow" is added to all
+    #             <a> tags.
     #
     # Returns the String HTML version of the tag.
-    def process_tag(tag)
+    def process_tag(tag, no_follow = false)
       if html = process_image_tag(tag)
-        return html
+        html
-      elsif html = process_file_link_tag(tag)
+      elsif html = process_file_link_tag(tag, no_follow)
-        return html
+        html
       else
-        return process_page_link_tag(tag)
+        process_page_link_tag(tag, no_follow)
       end
     end
 
@@ -229,11 +240,14 @@ module Gollum
 
     # Attempt to process the tag as a file link tag.
     #
-    # tag - The String tag contents (the stuff inside the double brackets).
+    # tag       - The String tag contents (the stuff inside the double 
+    #             brackets).
+    # no_follow - Boolean that determines if rel="nofollow" is added to all
+    #             <a> tags.
     #
     # Returns the String HTML if the tag is a valid file link tag or nil
     #   if it is not.
-    def process_file_link_tag(tag)
+    def process_file_link_tag(tag, no_follow = false)
       parts = tag.split('|')
       name  = parts[0].strip
       path  = parts[1] && parts[1].strip
@@ -245,26 +259,33 @@ module Gollum
         nil
       end
 
-      if name && path && file
+      tag = if name && path && file
         %{<a href="#{::File.join @wiki.base_path, file.path}">#{name}</a>}
       elsif name && path
         %{<a href="#{path}">#{name}</a>}
       else
         nil
       end
+      if tag && no_follow
+        tag.sub! /^<a/, '<a ref="nofollow"'
+      end
+      tag
     end
 
     # Attempt to process the tag as a page link tag.
     #
-    # tag - The String tag contents (the stuff inside the double brackets).
+    # tag       - The String tag contents (the stuff inside the double 
+    #             brackets).
+    # no_follow - Boolean that determines if rel="nofollow" is added to all
+    #             <a> tags.
     #
     # Returns the String HTML if the tag is a valid page link tag or nil
     #   if it is not.
-    def process_page_link_tag(tag)
+    def process_page_link_tag(tag, no_follow = false)
       parts = tag.split('|')
       name  = parts[0].strip
       cname = Page.cname((parts[1] || parts[0]).strip)
-      if name =~ %r{^https?://} && parts[1].nil?
+      tag = if name =~ %r{^https?://} && parts[1].nil?
         %{<a href="#{name}">#{name}</a>}
       else
         presence    = "absent"
@@ -277,6 +298,10 @@ module Gollum
         link = ::File.join(@wiki.base_path, CGI.escape(link_name))
         %{<a class="internal #{presence}" href="#{link}#{extra}">#{name}</a>}
       end
+      if tag && no_follow
+        tag.sub! /^<a/, '<a ref="nofollow"'
+      end
+      tag
     end
 
     # Find the given file in the repo.

lib/gollum/page.rb

@@ -14,6 +14,11 @@ module Gollum
                      :asciidoc => "AsciiDoc",
                      :pod      => "Pod" }
 
+    # Sets a Boolean determing whether this page is a historical version.
+    #
+    # Returns nothing.
+    attr_writer :historical
+
     # Checks if a filename has a valid extension understood by GitHub::Markup.
     #
     # filename - String filename, like "Home.md".
@@ -115,7 +120,7 @@ module Gollum
     #
     # Returns the String data.
     def formatted_data
-      @blob && Gollum::Markup.new(self).render
+      @blob && Gollum::Markup.new(self).render(historical?)
     end
 
     # Public: The format of the page.
@@ -193,6 +198,15 @@ module Gollum
       find_page_in_tree(map, '_Footer', '')
     end
 
+    # Gets a Boolean determining whether this page is a historical version.  
+    # Historical pages are pulled using exact SHA hashes and format all links
+    # with rel="nofollow"
+    #
+    # Returns true if the page is pulled from a named branch or tag, or false.
+    def historical?
+      !!@historical
+    end
+
     #########################################################################
     #
     # Class Methods
@@ -259,7 +273,8 @@ module Gollum
       map = @wiki.tree_map_for(version)
       if page = find_page_in_tree(map, name)
         sha = @wiki.ref_map[version] || version
-        page.version = Grit::Commit.create(@wiki.repo, :id => sha)
+        page.version    = Grit::Commit.create(@wiki.repo, :id => sha)
+        page.historical = sha == version
         page
       end
     rescue Grit::GitRuby::Repository::NoSuchShaFound

test/test_markup.rb

@@ -71,6 +71,16 @@ context "Markup" do
     assert_match /\>Bilbo Baggins\</,        output
   end
 
+  test "adds nofollow to links on historical pages" do
+    sha1 = @wiki.write_page("Sauron", :markdown, "a [[b]] c", commit_details)
+    page = @wiki.page("Sauron")
+    sha2 = @wiki.update_page(page, page.name, :markdown, "c [[b]] a", commit_details)
+    regx = /rel="nofollow"/
+    assert_no_match regx, page.formatted_data
+    assert_match    regx, @wiki.page(page.name, sha1).formatted_data
+    assert_match    regx, @wiki.page(page.name, sha2).formatted_data
+  end
+
   test "absent page link" do
     @wiki.write_page("Tolkien", :markdown, "a [[J. R. R. Tolkien]]'s b", commit_details)