Ensure validates_uniqueness_of considers limit on the field. [#1042 state:resolved]

Signed-off-by: Pratik Naik <pratiknaik@gmail.com>

activerecord/lib/active_record/validations.rb

@@ -720,20 +720,20 @@ module ActiveRecord
           # class (which has a database table to query from).
           finder_class = class_hierarchy.detect { |klass| !klass.abstract_class? }
 
-          is_text_column = finder_class.columns_hash[attr_name.to_s].text?
+          column = finder_class.columns_hash[attr_name.to_s]
 
           if value.nil?
             comparison_operator = "IS ?"
-          elsif is_text_column
+          elsif column.text?
             comparison_operator = "#{connection.case_sensitive_equality_operator} ?"
-            value = value.to_s
+            value = column.limit ? value.to_s[0, column.limit] : value.to_s
           else
             comparison_operator = "= ?"
           end
 
           sql_attribute = "#{record.class.quoted_table_name}.#{connection.quote_column_name(attr_name)}"
 
-          if value.nil? || (configuration[:case_sensitive] || !is_text_column)
+          if value.nil? || (configuration[:case_sensitive] || !column.text?)
             condition_sql = "#{sql_attribute} #{comparison_operator}"
             condition_params = [value]
           else

activerecord/test/cases/validations_test.rb

@@ -8,6 +8,7 @@ require 'models/warehouse_thing'
 require 'models/guid'
 require 'models/owner'
 require 'models/pet'
+require 'models/event'
 
 # The following methods in Topic are used in test_conditional_validation_*
 class Topic
@@ -530,6 +531,14 @@ class ValidationsTest < ActiveRecord::TestCase
     end
   end
 
+  def test_validate_uniqueness_with_limit
+    # Event.title is limited to 5 characters
+    e1 = Event.create(:title => "abcde")
+    assert e1.valid?, "Could not create an event with a unique, 5 character title"
+    e2 = Event.create(:title => "abcdefgh")
+    assert !e2.valid?, "Created an event whose title, with limit taken into account, is not unique"
+  end
+
   def test_validate_straight_inheritance_uniqueness
     w1 = IneptWizard.create(:name => "Rincewind", :city => "Ankh-Morpork")
     assert w1.valid?, "Saving w1"

activerecord/test/models/event.rb

@@ -0,0 +1,3 @@
+class Event < ActiveRecord::Base
+  validates_uniqueness_of :title
+end

activerecord/test/schema/schema.rb

@@ -155,6 +155,10 @@ ActiveRecord::Schema.define do
     t.integer :course_id, :null => false
   end
 
+  create_table :events, :force => true do |t|
+    t.string :title, :limit => 5
+  end
+
   create_table :funny_jokes, :force => true do |t|
     t.string :name
   end