This was introduced in [2684f17a] 💣

* Fix the problem on manipulating on the `ActiveSupport::SafeBuffer`
* Make sure that we run `escape_javascript` on the `String`, to avoid unexpected behavior.

Adapt [823aa223] to make sure we perform cloning before manipulation only on `OutputBuffer`.

After the fragment rendering, `Builder` returns the `String` object instead of `ActionView::OutputBuffer`. Somehow the same procedure which was in [823aa223] does not play nice with the String, and result in the fragment got lost.

Fragment caching needs to operate on the pure output, not the safebuffer.

safebuffer.

Also make sure that the versions of those methods which modify a string in place such as gsub! can't be called on safe buffers at all.

Conflicts:

	activesupport/test/safe_buffer_test.rb

Allow polymorphic has_one to work when the association is set before the owner has been saved. Fixes #1524.

When you add a record to a polymorphic has_one, you should be able to access the owner from the associated record

Fix typo

Fixes #1489

Rails::Server#app should be nice with Rack::URLMap

Fix a couple of helper requires that were missed. This was causing the tests to fail to run on 1.8.7.

added  tests for update_column

Added missing assert to test checking form with namespaced isolated model and fixed helpers to work correctly in such case

Don't ensure all keys in build_results are only written once, otherwise we get false positive builds reported.