rails/rails — pull request #18162 by romaimperator (2014-12-23 06:33:03+00:00)
Title: Fixing numeric attrs when set to same negative value

This bug occurs when an attribute of an ActiveRecord model is an
ActiveRecord::Type::Integer type or a ActiveRecord::Type::Decimal type (or any
other type that includes the ActiveRecord::Type::Numeric module. When the value
of the attribute is negative and is set to the same negative value, it is marked
as changed.

Take the following example of a Person model with the integer attribute age:

class Person < ActiveRecord::Base
# age :integer(4)
end

The following will produce the error:

person = Person.new(age: -1)
person.age = -1
person.changes
=> { "age" => [-1, -1] }
person.age_changed?
=> true

The problematic line is here:

module ActiveRecord
module Type
module Numeric
...

def non_numeric_string?(value)
# 'wibble'.to_i will give zero, we want to make sure
# that we aren't marking int zero to string zero as
# changed.
value.to_s !~ /\A\d+\.?\d*\z/
end
end
end
end

The regex match doesn't accept numbers with a leading '-'. Fixes issue #18161.