rails/rails — pull request #16145 by phoet (2014-07-11 23:49:03+00:00)
Title: don't log errors when all is fine

this change prevents rails from logging verbose stack-traces when the exceptional case has already been handled by the developers.

so when your config looks like this

```ruby
class ActiveSupport::TestCase
set_fixture_class fixture_class_name: SomeModel, [...]
fixtures :all
[...]
```

it does not print a warning containing a possible 100 lines long stack-trace.

the problem only occurs on weird edge-cases where models are inherited+inlined in other model-classes. so something like this

```ruby
class User < ActiveRecord::Base
class Admin < User
end
end
```

what would be a good way to test this?