2 files changed, 5 insertions, 4 deletions
diff --git a/activerecord/lib/active_record/validations/associated.rb b/activerecord/lib/active_record/validations/associated.rb
index 7af0352a31..9f072c4c39 100644
--- a/activerecord/lib/active_record/validations/associated.rb
+++ b/activerecord/lib/active_record/validations/associated.rb
@@ -2,8 +2,9 @@ module ActiveRecord
   module Validations
     class AssociatedValidator < ActiveModel::EachValidator
       def validate_each(record, attribute, value)
-        return if (value.is_a?(Array) ? value : [value]).collect{ |r| r.nil? || r.valid? }.all?
-        record.errors.add(attribute, :invalid, options.merge(:value => value))
+        if Array.wrap(value).reject {|r| r.marked_for_destruction? || r.valid?}.any?
+          record.errors.add(attribute, :invalid, options.merge(:value => value))
+        end
       end
     end
 
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb
index 484b1d369b..2e2ea8c42b 100644
--- a/activerecord/lib/active_record/validations/uniqueness.rb
+++ b/activerecord/lib/active_record/validations/uniqueness.rb
@@ -57,8 +57,8 @@ module ActiveRecord
         value = column.limit ? value.to_s.mb_chars[0, column.limit] : value.to_s if column.text?
 
         if !options[:case_sensitive] && value && column.text?
-          # will use SQL LOWER function before comparison
-          relation = table[attribute].lower.eq(table.lower(value))
+          # will use SQL LOWER function before comparison, unless it detects a case insensitive collation
+          relation = klass.connection.case_insensitive_comparison(table, attribute, column, value)
         else
           value    = klass.connection.case_sensitive_modifier(value)
           relation = table[attribute].eq(value)