Fixes #11.

lib/fuzzily/searchable.rb

@@ -75,7 +75,8 @@ def make_field_fuzzily_searchable(field, options={})
 
           trigram_class.transaction do
             batch.each { |record| record.send(trigram_association).delete_all }
-
+            return if inserts.empty?
+
             if supports_bulk_inserts
               trigram_class.connection.insert(insert_sql + inserts.join(", "))
             else

lib/fuzzily/trigram.rb

@@ -4,6 +4,7 @@ module Fuzzily
   class String < SimpleDelegator
 
     def trigrams
+      return [] if __getobj__.nil?
       normalized = self.normalize
       number_of_trigrams = normalized.length - 3
       trigrams = (0..number_of_trigrams).map { |index| normalized[index,3] }.uniq
@@ -18,7 +19,6 @@ def scored_trigrams
     # Remove accents, downcase, replace spaces and word start with '*',
     # return list of normalized words
     def normalize
-      # Iconv.iconv('ascii//translit//ignore', 'utf-8', self).first.
       ActiveSupport::Multibyte::Chars.new(self).
         mb_chars.normalize(:kd).gsub(/[^\x00-\x7F]/,'').downcase.to_s.
         gsub(/[^a-z]/,' ').