Merge pull request #7548 from ernie/missing-attributes-query-fix

Raise MissingAttributeError on query methods

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")