3 files changed, 14 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/validations/length.rb b/activerecord/lib/active_record/validations/length.rb
index ef5a6cbbe7..5991fbad8e 100644
--- a/activerecord/lib/active_record/validations/length.rb
+++ b/activerecord/lib/active_record/validations/length.rb
@@ -2,11 +2,23 @@ module ActiveRecord
   module Validations
     class LengthValidator < ActiveModel::Validations::LengthValidator # :nodoc:
       def validate_each(record, attribute, association_or_value)
+        return unless should_validate?(record) || associations_are_dirty?(record)
         if association_or_value.respond_to?(:loaded?) && association_or_value.loaded?
           association_or_value = association_or_value.target.reject(&:marked_for_destruction?)
         end
         super
       end
+
+      def associations_are_dirty?(record)
+        attributes.any? do |attribute|
+          value = record.read_attribute_for_validation(attribute)
+          if value.respond_to?(:loaded?) && value.loaded?
+            value.target.any?(&:marked_for_destruction?)
+          else
+            false
+          end
+        end
+      end
     end
 
     module ClassMethods
diff --git a/activerecord/lib/active_record/validations/presence.rb b/activerecord/lib/active_record/validations/presence.rb
index 61b30749d9..75d5bd5a35 100644
--- a/activerecord/lib/active_record/validations/presence.rb
+++ b/activerecord/lib/active_record/validations/presence.rb
@@ -2,6 +2,7 @@ module ActiveRecord
   module Validations
     class PresenceValidator < ActiveModel::Validations::PresenceValidator # :nodoc:
       def validate(record)
+        return unless should_validate?(record)
         super
         attributes.each do |attribute|
           next unless record.class._reflect_on_association(attribute)
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb
index 8f7a46f2c7..ad56f637e3 100644
--- a/activerecord/lib/active_record/validations/uniqueness.rb
+++ b/activerecord/lib/active_record/validations/uniqueness.rb
@@ -11,6 +11,7 @@ module ActiveRecord
       end
 
       def validate_each(record, attribute, value)
+        return unless should_validate?(record)
         finder_class = find_finder_class_for(record)
         table = finder_class.arel_table
         value = map_enum_attribute(finder_class, attribute, value)