Raise MissingAttributeError on query methods

When calling a query method on an attribute that was not selected by
an ActiveRecord query, an ActiveModel::MissingAttributeError is not
raised. Instead, a nil value is returned, which will return false once
cast to boolean.

This is undesirable, as we should not give the impression that we know
the attribute's boolean value when we haven't loaded the attribute's
(possibly) non-boolean value from the database.

This issue is present on versions going back as far as 2.3, at least.

activerecord/CHANGELOG.md

@@ -1,5 +1,11 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Attribute predicate methods, such as `article.title?`, will now raise
+    `ActiveModel::MissingAttributeError` if the attribute being queried for
+    truthiness was not read from the database, instead of just returning false.
+
+    *Ernie Miller*
+
 *   `ActiveRecord::SchemaDumper` uses Ruby 1.9 style hash, which means that the
     schema.rb file will be generated using this new syntax from now on.
 

activerecord/lib/active_record/attribute_methods/query.rb

@@ -8,7 +8,7 @@ module ActiveRecord
       end
 
       def query_attribute(attr_name)
-        value = read_attribute(attr_name)
+        value = read_attribute(attr_name) { |n| missing_attribute(n, caller) }
 
         case value
         when true        then true

activerecord/test/cases/finder_test.rb

@@ -276,6 +276,7 @@ class FinderTest < ActiveRecord::TestCase
   def test_find_only_some_columns
     topic = Topic.all.merge!(:select => "author_name").find(1)
     assert_raise(ActiveModel::MissingAttributeError) {topic.title}
+    assert_raise(ActiveModel::MissingAttributeError) {topic.title?}
     assert_nil topic.read_attribute("title")
     assert_equal "David", topic.author_name
     assert !topic.attribute_present?("title")