disable versioning of posts when creating aliases/implications

app/models/post.rb

@@ -3,7 +3,7 @@ class Post < ActiveRecord::Base
   class DisapprovalError < Exception ; end
   class SearchError < Exception ; end
 
-  attr_accessor :old_tag_string, :old_parent_id, :has_constraints
+  attr_accessor :old_tag_string, :old_parent_id, :has_constraints, :disable_versioning
   after_destroy :delete_files
   after_destroy :delete_remote_files
   after_save :create_version
@@ -868,6 +868,8 @@ class Post < ActiveRecord::Base
 
   module VersionMethods
     def create_version
+      return if disable_versioning
+
       if created_at == updated_at
         CurrentUser.increment!(:post_update_count)
         versions.create(

app/models/tag_alias.rb

@@ -130,6 +130,7 @@ class TagAlias < ActiveRecord::Base
       escaped_antecedent_name = Regexp.escape(antecedent_name)
       fixed_tags = post.tag_string.sub(/(?:\A| )#{escaped_antecedent_name}(?:\Z| )/, " #{consequent_name} ").strip
       CurrentUser.scoped(creator, creator_ip_addr) do
+        post.disable_versioning = true
         post.update_attributes(
           :tag_string => fixed_tags
         )

app/models/tag_implication.rb

@@ -125,6 +125,7 @@ class TagImplication < ActiveRecord::Base
       escaped_antecedent_name = Regexp.escape(antecedent_name)
       fixed_tags = post.tag_string.sub(/(?:\A| )#{escaped_antecedent_name}(?:\Z| )/, " #{antecedent_name} #{descendant_names} ").strip
       CurrentUser.scoped(creator, creator_ip_addr) do
+        post.disable_versioning = true
         post.update_attributes(
           :tag_string => fixed_tags
         )