Merge branch 'master' into set_binds

* master: (2794 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:
	activerecord/lib/active_record/associations/join_dependency/join_association.rb
	activerecord/lib/active_record/relation/query_methods.rb

4 files changed, 7 insertions, 1 deletions

diff --git a/guides/code/getting_started/public/404.html b/guides/code/getting_started/public/404.html
index 3d287b135d..3265cc8e33 100644
--- a/guides/code/getting_started/public/404.html
+++ b/guides/code/getting_started/public/404.html
@@ -22,6 +22,7 @@
     border-top-right-radius: 9px;
     background-color: white;
     padding: 7px 4em 0 4em;
+    box-shadow: 0 3px 8px rgba(50, 50, 50, 0.17);
   }
 
   h1 {
@@ -37,6 +38,7 @@
     background-color: #F7F7F7;
     border: 1px solid #CCC;
     border-right-color: #999;
+    border-left-color: #999;
     border-bottom-color: #999;
     border-bottom-left-radius: 4px;
     border-bottom-right-radius: 4px;
diff --git a/guides/code/getting_started/public/422.html b/guides/code/getting_started/public/422.html
index 3b946bf4a4..d823a8fc77 100644
--- a/guides/code/getting_started/public/422.html
+++ b/guides/code/getting_started/public/422.html
@@ -22,6 +22,7 @@
     border-top-right-radius: 9px;
     background-color: white;
     padding: 7px 4em 0 4em;
+    box-shadow: 0 3px 8px rgba(50, 50, 50, 0.17);
   }
 
   h1 {
@@ -37,6 +38,7 @@
     background-color: #F7F7F7;
     border: 1px solid #CCC;
     border-right-color: #999;
+    border-left-color: #999;
     border-bottom-color: #999;
     border-bottom-left-radius: 4px;
     border-bottom-right-radius: 4px;
diff --git a/guides/code/getting_started/public/500.html b/guides/code/getting_started/public/500.html
index ccc4ad5656..ebf6d4c00c 100644
--- a/guides/code/getting_started/public/500.html
+++ b/guides/code/getting_started/public/500.html
@@ -22,6 +22,7 @@
     border-top-right-radius: 9px;
     background-color: white;
     padding: 7px 4em 0 4em;
+    box-shadow: 0 3px 8px rgba(50, 50, 50, 0.17);
   }
 
   h1 {
@@ -37,6 +38,7 @@
     background-color: #F7F7F7;
     border: 1px solid #CCC;
     border-right-color: #999;
+    border-left-color: #999;
     border-bottom-color: #999;
     border-bottom-left-radius: 4px;
     border-bottom-right-radius: 4px;
diff --git a/guides/code/getting_started/public/robots.txt b/guides/code/getting_started/public/robots.txt
index 1a3a5e4dd2..3c9c7c01f3 100644
--- a/guides/code/getting_started/public/robots.txt
+++ b/guides/code/getting_started/public/robots.txt
@@ -1,4 +1,4 @@
-# See http://www.robotstxt.org/wc/norobots.html for documentation on how to use the robots.txt file
+# See http://www.robotstxt.org/robotstxt.html for documentation on how to use the robots.txt file
 #
 # To ban all spiders from the entire site uncomment the next two lines:
 # User-agent: *