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
Update README.rdoc [ci skip]

Highlighted code
Update commands.rb content in initialization guide

[ci skip]
Add section for command_tasks in initialization guide

[ci skip]
Update security.md

Hi Guys 
I was reading through this guide last night and noticed a small mistake, would be great if you could update it. 
I changed the word 'building' to 'build' in line 20. 
"Web application frameworks are made to help developers building web applications"
Also dup `column_types` in AR::Result `initialize_copy`
Merge pull request #12749 from iantropov/issue_5303

Add test for ActiveRecord::Relation YAML serialization, for #5303 issue
Merge pull request #12740 from gaurish/patch-1

Improve Errors when Controller Name or Action isn't specfied
Remove order attribute from collector

Ruby 1.8 legacy. Since 1.9 hash preserves insertion order. No need for additional array to achieve this
Merge pull request #12838 from strzalek/remove_mime_type_order_var

Remove @order attribute from collector
Array#split preserving the calling array
Array#in_groups: documentation updated
Merge pull request #12839 from kuldeepaggarwal/array_split

Array#split preserving the calling array
Fix missing line and shadow on static error pages [ci skip]
Merge pull request #12841 from kuldeepaggarwal/in-group-documentation

Array#in_groups: documentation updated [ci skip]
autoload ChangeColumnDefinition (Fixes #12835)
Speed up Array#split
Ruby 2.0.0p247
Rehearsal ---------------------------------------
old  10.670000   0.150000  10.820000 ( 10.822651)
new   8.520000   0.050000   8.570000 (  8.571825)
----------------------------- total: 19.390000sec

          user     system      total        real
old  10.620000   0.170000  10.790000 ( 10.790409)
new   8.570000   0.110000   8.680000 (  8.686051)
Merge pull request #12842 from kuldeepaggarwal/array_split

Speed up Array#split when block is passed