Merge pull request #1976 from jekyll/fix-pagination-issue

Relative posts should never fail to build, even if @dir or @name is nil

lib/jekyll/page.rb

@@ -126,7 +126,7 @@ module Jekyll
 
     # The path to the page source file, relative to the site source
     def relative_path
-      File.join(@dir, @name)
+      File.join(*[@dir, @name].map(&:to_s).reject(&:empty?))
     end
 
     # Obtain destination path.

lib/jekyll/post.rb

@@ -123,7 +123,7 @@ module Jekyll
 
     # The path to the post source file, relative to the site source
     def relative_path
-      File.join(@dir, '_posts', @name)
+      File.join(*[@dir, "_posts", @name].map(&:to_s).reject(&:empty?))
     end
 
     # Compares Post objects. First compares the Post date. If the dates are