From b0c66a2f92eaed20890164f8f90b466c4e140645 Mon Sep 17 00:00:00 2001
From: Matthew Draper <matthew@trebex.net>
Date: Sun, 28 May 2017 11:00:07 +0930
Subject: [PATCH] Merge pull request #29249 from
 bradleypriest/numericality-precision-regression

Fix regression in Numericality validator
---
 activemodel/CHANGELOG.md                           |  6 ++++++
 .../lib/active_model/validations/numericality.rb   |  4 +++-
 activerecord/test/cases/validations_test.rb        | 14 ++++++++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/activemodel/CHANGELOG.md b/activemodel/CHANGELOG.md
index 1a48533842..cd747587a5 100644
--- a/activemodel/CHANGELOG.md
+++ b/activemodel/CHANGELOG.md
@@ -1,3 +1,9 @@
+*   Fix regression in numericality validator when comparing Decimal and Float input 
+    values with more scale than the schema.
+
+    *Bradley Priest*
+
+
 ## Rails 5.0.3 (May 12, 2017) ##
 
 *   The original string assigned to a model attribute is no longer incorrectly
diff --git a/activemodel/lib/active_model/validations/numericality.rb b/activemodel/lib/active_model/validations/numericality.rb
index 095590b44c..4f1c1143c2 100644
--- a/activemodel/lib/active_model/validations/numericality.rb
+++ b/activemodel/lib/active_model/validations/numericality.rb
@@ -39,7 +39,9 @@ module ActiveModel
           return
         end
 
-        unless raw_value.is_a?(Numeric)
+        if raw_value.is_a?(Numeric)
+          value = raw_value
+        else
           value = parse_raw_value_as_a_number(raw_value)
         end
 
diff --git a/activerecord/test/cases/validations_test.rb b/activerecord/test/cases/validations_test.rb
index 85e33d2218..1c51b247f3 100644
--- a/activerecord/test/cases/validations_test.rb
+++ b/activerecord/test/cases/validations_test.rb
@@ -169,6 +169,20 @@ class ValidationsTest < ActiveRecord::TestCase
     Topic.reset_column_information
   end
 
+  def test_numericality_validation_checks_against_raw_value
+    klass = Class.new(Topic) do
+      def self.model_name
+        ActiveModel::Name.new(self, nil, "Topic")
+      end
+      attribute :wibble, :decimal, scale: 2, precision: 9
+      validates_numericality_of :wibble, greater_than_or_equal_to: BigDecimal.new("97.18")
+    end
+
+    assert_not klass.new(wibble: "97.179").valid?
+    assert_not klass.new(wibble: 97.179).valid?
+    assert_not klass.new(wibble: BigDecimal.new("97.179")).valid?
+  end
+
   def test_acceptance_validator_doesnt_require_db_connection
     klass = Class.new(ActiveRecord::Base) do
       self.table_name = 'posts'