Migrations: gracefully handle missing migration files. Closes #5857.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4809 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

 *SVN*
 
+* Migrations: gracefully handle missing migration files.  #5857 [eli.gordon@gmail.com]
+
 * MySQL: update test schema for MySQL 5 strict mode.  #5861 [Tom Ward]
 
 * to_xml: correct naming of included associations.  #5831 [josh.starcher@gmail.com]

activerecord/lib/active_record/migration.rb

@@ -382,7 +382,8 @@ def down?
       end
       
       def reached_target_version?(version)
-        (up? && version.to_i - 1 == @target_version) || (down? && version.to_i == @target_version)
+        return false if @target_version == nil
+        (up? && version.to_i - 1 >= @target_version) || (down? && version.to_i <= @target_version)
       end
       
       def irrelevant_migration?(version)

activerecord/test/fixtures/migrations_with_missing_versions/1000_people_have_middle_names.rb

+class PeopleHaveMiddleNames < ActiveRecord::Migration
+  def self.up
+    add_column "people", "middle_name", :string
+  end
+  
+  def self.down
+    remove_column "people", "middle_name"
+  end
+end
\ No newline at end of file

activerecord/test/fixtures/migrations_with_missing_versions/1_people_have_last_names.rb

+class PeopleHaveLastNames < ActiveRecord::Migration
+  def self.up
+    add_column "people", "last_name", :string
+  end
+  
+  def self.down
+    remove_column "people", "last_name"
+  end
+end
\ No newline at end of file

activerecord/test/fixtures/migrations_with_missing_versions/3_we_need_reminders.rb

+class WeNeedReminders < ActiveRecord::Migration
+  def self.up
+    create_table("reminders") do |t|
+      t.column :content, :text
+      t.column :remind_at, :datetime
+    end
+  end
+  
+  def self.down
+    drop_table "reminders"
+  end
+end
\ No newline at end of file

activerecord/test/fixtures/migrations_with_missing_versions/4_innocent_jointable.rb

+class InnocentJointable < ActiveRecord::Migration
+  def self.up
+    create_table("people_reminders", :id => false) do |t|
+      t.column :reminder_id, :integer
+      t.column :person_id, :integer
+    end
+  end
+
+  def self.down
+    drop_table "people_reminders"
+  end
+end
\ No newline at end of file

activerecord/test/migration_test.rb

@@ -44,6 +44,7 @@ def teardown
         Person.connection.remove_column('people', column) rescue nil
       end
       Person.connection.remove_column("people", "first_name") rescue nil
+      Person.connection.remove_column("people", "middle_name") rescue nil
       Person.connection.add_column("people", "first_name", :string, :limit => 40)
       Person.reset_column_information
     end
@@ -661,5 +662,18 @@ def test_migrator_with_duplicates
         ActiveRecord::Migrator.migrate(File.dirname(__FILE__) + '/fixtures/migrations_with_duplicate/', nil)
       end
     end
+
+    def test_migrator_with_missing_version_numbers
+      ActiveRecord::Migrator.migrate(File.dirname(__FILE__) + '/fixtures/migrations_with_missing_versions/', 500)
+      assert !Person.column_methods_hash.include?(:middle_name)
+    	assert_equal 4, ActiveRecord::Migrator.current_version
+			
+			ActiveRecord::Migrator.migrate(File.dirname(__FILE__) + '/fixtures/migrations_with_missing_versions/', 2)
+			assert !Reminder.table_exists?
+      assert Person.column_methods_hash.include?(:last_name)			
+			assert_equal 2, ActiveRecord::Migrator.current_version
+    end
+    
+    
   end
 end