3 files changed, 22 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/attribute_assignment.rb b/activerecord/lib/active_record/attribute_assignment.rb
index a13bb9299a..75377bba57 100644
--- a/activerecord/lib/active_record/attribute_assignment.rb
+++ b/activerecord/lib/active_record/attribute_assignment.rb
@@ -45,7 +45,7 @@ module ActiveRecord
       if respond_to?("#{k}=")
         raise
       else
-        raise UnknownAttributeError, "unknown attribute: #{k}"
+        raise UnknownAttributeError.new(self, k)
       end
     end
 
diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb
index cd31147414..017b8bace6 100644
--- a/activerecord/lib/active_record/errors.rb
+++ b/activerecord/lib/active_record/errors.rb
@@ -159,6 +159,15 @@ module ActiveRecord
 
   # Raised when unknown attributes are supplied via mass assignment.
   class UnknownAttributeError < NoMethodError
+
+    attr_reader :record, :attribute
+
+    def initialize(record, attribute)
+      @record = record
+      @attribute = attribute.to_s
+      super("unknown attribute: #{attribute}")
+    end
+
   end
 
   # Raised when an error occurred while doing a mass assignment to an attribute through the
diff --git a/activerecord/test/cases/attribute_methods_test.rb b/activerecord/test/cases/attribute_methods_test.rb
index a181c513ae..d882d40ecb 100644
--- a/activerecord/test/cases/attribute_methods_test.rb
+++ b/activerecord/test/cases/attribute_methods_test.rb
@@ -711,6 +711,18 @@ class AttributeMethodsTest < ActiveRecord::TestCase
     assert_raise(ActiveRecord::UnknownAttributeError) { @target.new.attributes = { :title => "Ants in pants" } }
   end
 
+  def test_bulk_update_raise_unknown_attribute_errro
+    error = nil
+    begin
+      @target.new(:hello => "world")
+    rescue ActiveRecord::UnknownAttributeError => error
+    end
+    assert error
+    assert @target, error.record
+    assert "hello", error.attribute
+    assert "unknown attribute: hello", error.message
+  end
+
   def test_read_attribute_overwrites_private_method_not_considered_implemented
     # simulate a model with a db column that shares its name an inherited
     # private method (e.g. Object#system)