Merge pull request #2679 from amatsuda/nullify_abstract_class_table_name

do not compute table names for abstract classes

activerecord/lib/active_record/base.rb

@@ -624,6 +624,8 @@ module ActiveRecord #:nodoc:
 
       # Computes the table name, (re)sets it internally, and returns it.
       def reset_table_name #:nodoc:
+        return if abstract_class?
+
         self.table_name = compute_table_name
       end
 

activerecord/test/cases/base_test.rb

@@ -1625,6 +1625,10 @@ class BasicsTest < ActiveRecord::TestCase
     assert !LooseDescendant.abstract_class?
   end
 
+  def test_abstract_class_table_name
+    assert_nil AbstractCompany.table_name
+  end
+
   def test_base_class
     assert_equal LoosePerson,     LoosePerson.base_class
     assert_equal LooseDescendant, LooseDescendant.base_class