Fix migrations when migrating to a specified version number with a fresh database [#1 state:resolved]

Signed-off-by: Joshua Peek <josh@joshpeek.com>

activerecord/lib/active_record/migration.rb

@@ -364,8 +364,10 @@ module ActiveRecord
       end
 
       def current_version
-        Base.connection.select_values(
-          "SELECT version FROM #{schema_migrations_table_name}").map(&:to_i).max || 0
+        version = Base.connection.select_values(
+          "SELECT version FROM #{schema_migrations_table_name}"
+        ).map(&:to_i).max rescue nil
+        version || 0
       end
 
       def proper_table_name(name)

activerecord/test/cases/migration_test.rb

@@ -813,6 +813,13 @@ if ActiveRecord::Base.connection.supports_migrations?
       end
     end
 
+    def test_migrator_db_has_no_schema_migrations_table
+      ActiveRecord::Base.connection.execute("DROP TABLE schema_migrations;")
+      assert_nothing_raised do
+        ActiveRecord::Migrator.migrate(MIGRATIONS_ROOT + "/valid", 1)
+      end
+    end
+
     def test_migrator_verbosity
       ActiveRecord::Migrator.up(MIGRATIONS_ROOT + "/valid", 1)
       assert PeopleHaveLastNames.message_count > 0
@@ -1010,7 +1017,7 @@ if ActiveRecord::Base.connection.supports_migrations?
       end
 
   end
-
+  
   uses_mocha 'Sexy migration tests' do
     class SexyMigrationsTest < ActiveRecord::TestCase
       def test_references_column_type_adds_id