From #14026:

    Specific rbx-2 to limit testing on Rubinius 2.x (since there will be
    other versions of Rubinius > 2.x soon).

    Also, as of Rubinius 2.2.5, it is no longer necessary to bundle the
    rubysl gem.

This is what Rails master/4.1 supports, so we don't need to add rubysl to
gemfiles anymore.

`before_add` callbacks are fired before the record is saved on
`has_and_belongs_to_many` assocations *and* on `has_many :through`
associations.  Before this change, `before_add` callbacks would be fired
before the record was saved on `has_and_belongs_to_many` associations, but
*not* on `has_many :through` associations.

Fixes #14144

Fix test name typo in app generator tests.

Conflicts:
	activerecord/CHANGELOG.md

travis s/2.1.0/2.1.1

Handle missing environment from non empty config

Skip test_migrate_revert_add_index_with_name for some databases

do not allow to create duplicate indexes on the same columns

We noticed the rails gem increased in size between the beta and rc
versions, and the reason is that some guides images were updated but not
properly optimized, and one image changed from png to jpg, way bigger.

Converting the jpg image back to png, and using ImageOptim to optimize
all the images for web view, improves the situation [ci skip].

---

In current master/4-1-stable:

    508K  guides/assets/images/getting_started/

In v4.1.0.beta1:

    268K  guides/assets/images/getting_started/

In 4-0-stable

    328K  guides/assets/images/getting_started/

After the patch:

    260K  guides/assets/images/getting_started/

Add missing parantheses in index_exists?

Remove 4-1 related entries from master [ci skip]

See 449039a8 for the original commit.

Sungularize ActionController::UnpermittedParameters error in case when only 1 parameter is unpermitted.

Standardized punctuation.

[skip ci] Fixing typo in documentation: actionview/lib/action_view/helpers/url_helper.rb

This is a follow up to #14170. While backporting I recognized
that this call is not needed at all.

there could be more than 10 nested records

Go with #presence_in instead of #present_in -- it doesnt sound quite as good, but the closer relationship to #presence over #present is ultimately worth it

Simple Sungularize ActionController::UnpermittedParameters error in case when only 1 parameter is unpermitted.

This is a follow up to #13515. It includes the name given and
the singularized version in the warning message. This will aide the user
to see wether the detected singular was right or not.

coerce strings when reading attributes

Extract local cache middleware

Extract LocalCache Middleware, so it can requires rack dependencies,
without adding rack dependencies to `AS::Cache::Strategy::LocalCache`.

conflicting private method defined on its ancestors.

The problem is that `method_defined_within?(name, klass, superklass)`
only works correclty when `klass` and `superklass` are both `Class`es.

If both `klass` and `superklass` are both `Class`es, they share the
same inheritance chain, so if a method is defined on `klass` but not
`superklass`, this method must be introduced at some point between
`klass` and `superklass`.

This does not work when `superklass` is a `Module`. A `Module`'s
inheritance chain contains just itself. So if a method is defined on
`klass` but not on `superklass`, the method could still be defined
somewhere upstream, e.g. in `Object`.

This fix works by avoiding calling `method_defined_within?` with a
module while still fufilling the requirement (checking that the
method is defined withing `superclass` but not is not a generated
attribute method).

4d8ee288 is likely an attempted partial fix for this problem. This
unrolls that fix and properly check the `superclass` as intended.

Fixes #11569.

Dynamically define PostgreSQL Range OIDs

The Ruby Range object does not support excluding beginnings.
We currently support excluding beginnings for some subtypes using
manually by incrementing them (now using the `#succ` method).
This is approach is flawed as it's not equal to an excluding beginning.

This commit deprecates the current support for excluding beginnings.
It also raises an `ArgumentError` for subtypes that do not implement the `succ`
method.

This is a temporary solution to get rid of the broken state. We might still
add complete support for excluding beginnings afterwards. (Probably with a
new `PGRange` object, which acts like a `Range` but has excluding beginnings.

This gets AR working with custom defined range types. It also
removes the need for subtype specific branches in `OID::Range`.

This expands the interface of all `OID` types with the `infinity` method.
It's responsible to provide a value for positive and negative infinity.