Fix bulk change table ignores comment option on PostgreSQL.

activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb

@@ -700,6 +700,11 @@ def change_column_sql(table_name, column_name, type, options = {})
             sql
           end
 
+          def add_column_for_alter(table_name, column_name, type, options = {})
+            return super unless options.key?(:comment)
+            [super, Proc.new { change_column_comment(table_name, column_name, options[:comment]) }]
+          end
+
           def change_column_for_alter(table_name, column_name, type, options = {})
             sqls = [change_column_sql(table_name, column_name, type, options)]
             sqls << change_column_default_for_alter(table_name, column_name, options[:default]) if options.key?(:default)
@@ -708,7 +713,6 @@ def change_column_for_alter(table_name, column_name, type, options = {})
             sqls
           end
 
-
           # Changes the default value of a table column.
           def change_column_default_for_alter(table_name, column_name, default_or_changes) # :nodoc:
             column = column_for(table_name, column_name)

activerecord/test/cases/migration_test.rb

@@ -793,19 +793,28 @@ def setup
     end
 
     def test_adding_multiple_columns
-      assert_queries(1) do
+      classname = ActiveRecord::Base.connection.class.name[/[^:]*$/]
+      expected_query_count = {
+        "Mysql2Adapter"     => 1,
+        "PostgreSQLAdapter" => 2, # one for bulk change, one for comment
+      }.fetch(classname) {
+        raise "need an expected query count for #{classname}"
+      }
+
+      assert_queries(expected_query_count) do
         with_bulk_change_table do |t|
           t.column :name, :string
           t.string :qualification, :experience
           t.integer :age, default: 0
-          t.date :birthdate
+          t.date :birthdate, comment: "This is a comment"
           t.timestamps null: true
         end
       end
 
       assert_equal 8, columns.size
       [:name, :qualification, :experience].each { |s| assert_equal :string, column(s).type }
       assert_equal "0", column(:age).default
+      assert_equal "This is a comment", column(:birthdate).comment
     end
 
     def test_removing_columns