Anemone::Page#links: restored upwards dir traversal

[FIXRM rapid7#7853]

Author: tasos-r7

lib/anemone/page.rb

@@ -103,17 +103,21 @@ def links
       @links = run_extractors
 
       @links |= @links.map do |u|
-        # back-off to the parent dir
+          # back-off to the parent dir
           to_absolute( URI( u.path.gsub( /(.*\/)[^\/]+$/, "\\1" ) ) ) rescue next
       end.uniq.compact
 
-      @links |= @links.map do |u|
-          bits = u.path.split( '/' )
-          while bits.length > 0
-          bits.pop
-          to_absolute( URI( bits.join( '/' ) ) ) rescue next
-          end
-      end.uniq.compact
+      nlinks = []
+      @links.each do |u|
+	      bits = u.path.split('/')
+	      while(bits.length > 0)
+		      bits.pop
+		      j = bits.join('/')
+		      j = '/' if j.empty?
+		      nlinks << to_absolute(URI(j)) rescue next
+	      end
+      end
+      @links |= nlinks
 
       @links.flatten!
       @links.uniq!