rails/rails — pull request #4399 by kennyj (2012-01-10 15:50:06+00:00)
Title: migrate(:down) method with table_name_prefix

I found the following issues, while a survey of GH #4259.

If we execute migrate(:down) method with table_name_prefix, an exception (table isn't exists) is raised.
When we call change method (down direction), It seems that Migrator.proper_table_name method is called twice.

For example,

```
1) ActiveRecord::Base.table_name_prefix = "foo_"
2) def change
create_table "hourses" do |t|
...
end
end

=> executed: create table foo_hourses ...

3) migrate(:down)

=> executed: drop table foo_foo_hourses ...
```