Update workaround for "Outside the Scope of Strong Parameters" 

The previous example of how to permit a hash of unknown keys used .tap, but had the side effect of logging an "Unpermitted parameters" message despite being a successful workaround. The proposed workaround is ever so slightly better, imo, because it won't result in an "Unpermitted parameters" message being logged.
Fix undefined method error for NilClass

Add .try to prevent undefined method error for NilClass.
Add test for ActiveRecord::Relation YAML serialization, for #5303 issue
Improve Errors when Controller Name or Action isn't specfied

These errors occur when, there routes are wrongly defined.

example, the following line would cause a missing :action error

    root "welcomeindex"

Mostly beginners are expected to hit these errors, so lets improve the error message a bit to make their learning experience bit better.
Don't swallow exceptions in transctional statements

The MySQL connection adapater swallows all StandardError exceptions,
which includes Mysql::Error and Mysql2::Error. The comment in the
exception clause claims errors thrown here indicate that transactions
aren't supported by the server but that isn't necessarily true. It's
possible the MySQL server has gone away and swallowing a failed commit
may let the application return a successful response when the data has
not been saved. Also, replication libraries like Galera require that the
application handle exceptions thrown at BEGIN/COMMIT.

I'm unable to determine what version of MySQL threw an exception for
transactional statements. I tried as far back as 3.23.49 with InnoDB
disabled but BEGIN & COMMIT statements do not throw an error. If there's
a real case for this logic to continue, we could instead push this
behavior into a configuration setting.

The exception swallowing has been there since the beginning:
db045dbbf60b53dbe013ef25554fd013baf88134
add autoload :TransactionState to fix Marshal.load issues
revised changelog comment to be less than 80 chars
Fixed plugin_generator test

Template replay needs to happen after bundle.

As we are doing TemplateRecording in apply_rails_template.

here are few commits for changes

8beb42cfbc41753ae4dbb91e16abcd1fb7d00356
9104702be61253f9448ca070a22fc86bb4299555
Merge pull request #12798 from arunagw/plugin-generators-test

Fixed plugin_generator test
sub! can return nil

Revert "drop one more string allocation"

This reverts commit 4d15661d6c46c86a62ee1fc358f4b3ef9dd9f2ea.
Merge pull request #12799 from arunagw/aa-av-test-fixes

Don't call sub! since it may return nil. Reverts 4d15661.
Added platform dependent gems


See #12475

If people are on rbx they will get the desired gem
Warning removed for ruby-head
Merge pull request #12800 from raysrashmi/warning-removed-ruby-trunk

Warning removed for ruby-head
Merge pull request #12795 from arunagw/plateform-dependent-gems

Added platform dependent gems
Merge pull request #12791 from jasonayre/ja/fix_autoload_error

add autoload :TransactionState to fix Marshal.load issues
Removed unused require
Extract common database defaults; better use of YAML
Merge pull request #12292 from bf4/better_database_yaml

Extract common database defaults; better use of YAML
Merge pull request #12803 from arunagw/remove-unused-require

Removed unused require