Merge branch 'master' into laurocaetano-fix_send_file

* master: (536 commits)
  doc, API example on how to use `Model#exists?` with multiple IDs. [ci skip]
  Restore DATABASE_URL even if it's nil in connection_handler test
  [ci skip] - error_messages_for has been deprecated since 2.3.8 - lets reduce any confusion for users
  Ensure Active Record connection consistency
  Revert "ask the fixture set for the sql statements"
  Check `respond_to` before delegation due to: https://github.com/ruby/ruby/commit/d781caaf313b8649948c107bba277e5ad7307314
  Adding Hash#compact and Hash#compact! methods
  MySQL version 4.1 was EOL on December 31, 2009 We should at least recommend modern versions of MySQL to users.
  clear cache on body close so that cache remains during rendering
  add a more restricted codepath for templates fixes #13390
  refactor generator tests to use block form of Tempfile
  Fix typo [ci skip]
  Move finish_template as the last public method in the generator
  Minor typos fix [ci skip]
  make `change_column_null` reversible. Closes #13576.
  create/drop test and development databases only if RAILS_ENV is nil
  Revert "Speedup String#to"
  typo fix in test name. [ci skip].
  `core_ext/string/access.rb` test what we are documenting.
  Fix typo in image_tag documentation
  ...

Conflicts:
	actionpack/CHANGELOG.md

2 files changed, 20 insertions, 32 deletions

diff --git a/activesupport/lib/active_support/values/time_zone.rb b/activesupport/lib/active_support/values/time_zone.rb
index 3cf82a24b9..beaac42fa1 100644
--- a/activesupport/lib/active_support/values/time_zone.rb
+++ b/activesupport/lib/active_support/values/time_zone.rb
@@ -1,3 +1,5 @@
+require 'tzinfo'
+require 'thread_safe'
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/object/try'
 
@@ -184,6 +186,8 @@ module ActiveSupport
     UTC_OFFSET_WITH_COLON = '%s%02d:%02d'
     UTC_OFFSET_WITHOUT_COLON = UTC_OFFSET_WITH_COLON.sub(':', '')
 
+    @lazy_zones_map = ThreadSafe::Cache.new
+
     # Assumes self represents an offset from UTC in seconds (as returned from
     # Time#utc_offset) and turns this into an +HH:MM formatted string.
     #
@@ -205,8 +209,6 @@ module ActiveSupport
     # (GMT). Seconds were chosen as the offset unit because that is the unit
     # that Ruby uses to represent time zone offsets (see Time#utc_offset).
     def initialize(name, utc_offset = nil, tzinfo = nil)
-      self.class.send(:require_tzinfo)
-
       @name = name
       @utc_offset = utc_offset
       @tzinfo = tzinfo || TimeZone.find_tzinfo(name)
@@ -232,6 +234,7 @@ module ActiveSupport
     # Compare this time zone to the parameter. The two are compared first on
     # their offsets, and then by name.
     def <=>(zone)
+      return unless zone.respond_to? :utc_offset
       result = (utc_offset <=> zone.utc_offset)
       result = (name <=> zone.name) if result == 0
       result
@@ -314,6 +317,16 @@ module ActiveSupport
       tzinfo.now.to_date
     end
 
+    # Returns the next date in this time zone.
+    def tomorrow
+      today + 1
+    end
+
+    # Returns the previous date in this time zone.
+    def yesterday
+      today - 1
+    end
+
     # Adjust the given time to the simultaneous time in the time zone
     # represented by +self+. Returns a Time.utc() instance -- if you want an
     # ActiveSupport::TimeWithZone instance, use Time#in_time_zone() instead.
@@ -346,14 +359,14 @@ module ActiveSupport
     class << self
       alias_method :create, :new
 
-      # Return a TimeZone instance with the given name, or +nil+ if no
+      # Returns a TimeZone instance with the given name, or +nil+ if no
       # such TimeZone instance exists. (This exists to support the use of
       # this class with the +composed_of+ macro.)
       def new(name)
         self[name]
       end
 
-      # Return an array of all TimeZone objects. There are multiple
+      # Returns an array of all TimeZone objects. There are multiple
       # TimeZone objects per time zone, in many cases, to make it easier
       # for users to find their own time zone.
       def all
@@ -362,10 +375,8 @@ module ActiveSupport
 
       def zones_map
         @zones_map ||= begin
-          new_zones_names = MAPPING.keys - lazy_zones_map.keys
-          new_zones       = Hash[new_zones_names.map { |place| [place, create(place)] }]
-
-          lazy_zones_map.merge(new_zones)
+          MAPPING.each_key {|place| self[place]} # load all the zones
+          @lazy_zones_map
         end
       end
 
@@ -378,7 +389,7 @@ module ActiveSupport
         case arg
           when String
           begin
-            lazy_zones_map[arg] ||= lookup(arg).tap { |tz| tz.utc_offset }
+            @lazy_zones_map[arg] ||= create(arg).tap { |tz| tz.utc_offset }
           rescue TZInfo::InvalidTimezoneIdentifier
             nil
           end
@@ -395,29 +406,6 @@ module ActiveSupport
       def us_zones
         @us_zones ||= all.find_all { |z| z.name =~ /US|Arizona|Indiana|Hawaii|Alaska/ }
       end
-
-      protected
-
-        def require_tzinfo
-          require 'tzinfo' unless defined?(::TZInfo)
-        rescue LoadError
-          $stderr.puts "You don't have tzinfo installed in your application. Please add it to your Gemfile and run bundle install"
-          raise
-        end
-
-      private
-
-        def lookup(name)
-          (tzinfo = find_tzinfo(name)) && create(tzinfo.name.freeze)
-        end
-
-        def lazy_zones_map
-          require_tzinfo
-
-          @lazy_zones_map ||= Hash.new do |hash, place|
-            hash[place] = create(place) if MAPPING.has_key?(place)
-          end
-        end
     end
 
     private
diff --git a/activesupport/lib/active_support/values/unicode_tables.dat b/activesupport/lib/active_support/values/unicode_tables.dat
index 2571faa019..394ee95f4b 100644
--- a/activesupport/lib/active_support/values/unicode_tables.dat
+++ b/activesupport/lib/active_support/values/unicode_tables.dat