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

6 files changed, 143 insertions, 17 deletions

diff --git a/activerecord/test/cases/adapters/mysql2/boolean_test.rb b/activerecord/test/cases/adapters/mysql2/boolean_test.rb
new file mode 100644
index 0000000000..267aa232d9
--- /dev/null
+++ b/activerecord/test/cases/adapters/mysql2/boolean_test.rb
@@ -0,0 +1,91 @@
+require "cases/helper"
+
+class Mysql2BooleanTest < ActiveRecord::TestCase
+  self.use_transactional_fixtures = false
+
+  class BooleanType < ActiveRecord::Base
+    self.table_name = "mysql_booleans"
+  end
+
+  setup do
+    @connection = ActiveRecord::Base.connection
+    @connection.create_table("mysql_booleans") do |t|
+      t.boolean "archived"
+      t.string "published", limit: 1
+    end
+    BooleanType.reset_column_information
+
+    @emulate_booleans = ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans
+  end
+
+  teardown do
+    emulate_booleans @emulate_booleans
+    @connection.drop_table "mysql_booleans"
+  end
+
+  test "column type with emulated booleans" do
+    emulate_booleans true
+
+    assert_equal :boolean, boolean_column.type
+    assert_equal :string, string_column.type
+  end
+
+  test "column type without emulated booleans" do
+    emulate_booleans false
+
+    assert_equal :integer, boolean_column.type
+    assert_equal :string, string_column.type
+  end
+
+  test "test type casting with emulated booleans" do
+    emulate_booleans true
+
+    boolean = BooleanType.create!(archived: true, published: true)
+    attributes = boolean.reload.attributes_before_type_cast
+
+    assert_equal 1, attributes["archived"]
+    assert_equal "1", attributes["published"]
+
+    assert_equal 1, @connection.type_cast(true, boolean_column)
+    assert_equal 1, @connection.type_cast(true, string_column)
+  end
+
+  test "test type casting without emulated booleans" do
+    emulate_booleans false
+
+    boolean = BooleanType.create!(archived: true, published: true)
+    attributes = boolean.reload.attributes_before_type_cast
+
+    assert_equal 1, attributes["archived"]
+    assert_equal "1", attributes["published"]
+
+    assert_equal 1, @connection.type_cast(true, boolean_column)
+    assert_equal 1, @connection.type_cast(true, string_column)
+  end
+
+  test "with booleans stored as 1 and 0" do
+    @connection.execute "INSERT INTO mysql_booleans(archived, published) VALUES(1, '1')"
+    boolean = BooleanType.first
+    assert_equal true, boolean.archived
+    assert_equal "1", boolean.published
+  end
+
+  test "with booleans stored as t" do
+    @connection.execute "INSERT INTO mysql_booleans(published) VALUES('t')"
+    boolean = BooleanType.first
+    assert_equal "t", boolean.published
+  end
+
+  def boolean_column
+    BooleanType.columns.find { |c| c.name == 'archived' }
+  end
+
+  def string_column
+    BooleanType.columns.find { |c| c.name == 'published' }
+  end
+
+  def emulate_booleans(value)
+    ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans = value
+    BooleanType.reset_column_information
+  end
+end
diff --git a/activerecord/test/cases/adapters/mysql2/connection_test.rb b/activerecord/test/cases/adapters/mysql2/connection_test.rb
index fedd9f603c..9b7202c915 100644
--- a/activerecord/test/cases/adapters/mysql2/connection_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/connection_test.rb
@@ -3,14 +3,22 @@ require "cases/helper"
 class MysqlConnectionTest < ActiveRecord::TestCase
   def setup
     super
+    @subscriber = SQLSubscriber.new
+    ActiveSupport::Notifications.subscribe('sql.active_record', @subscriber)
     @connection = ActiveRecord::Base.connection
-    @connection.extend(LogIntercepter)
-    @connection.intercepted = true
   end
 
   def teardown
-    @connection.intercepted = false
-    @connection.logged = []
+    ActiveSupport::Notifications.unsubscribe(@subscriber)
+    super
+  end
+
+  def test_bad_connection
+    assert_raise ActiveRecord::NoDatabaseError do
+      configuration = ActiveRecord::Base.configurations['arunit'].merge(database: 'inexistent_activerecord_unittest')
+      connection = ActiveRecord::Base.mysql2_connection(configuration)
+      connection.exec_query('drop table if exists ex')
+    end
   end
 
   def test_no_automatic_reconnection_after_timeout
@@ -18,6 +26,11 @@ class MysqlConnectionTest < ActiveRecord::TestCase
     @connection.update('set @@wait_timeout=1')
     sleep 2
     assert !@connection.active?
+
+    # Repair all fixture connections so other tests won't break.
+    @fixture_connections.each do |c|
+      c.verify!
+    end
   end
 
   def test_successful_reconnection_after_timeout_with_manual_reconnect
@@ -72,14 +85,14 @@ class MysqlConnectionTest < ActiveRecord::TestCase
 
   def test_logs_name_show_variable
     @connection.show_variable 'foo'
-    assert_equal "SCHEMA", @connection.logged[0][1]
+    assert_equal "SCHEMA", @subscriber.logged[0][1]
   end
 
   def test_logs_name_rename_column_sql
     @connection.execute "CREATE TABLE `bar_baz` (`foo` varchar(255))"
-    @connection.logged = []
+    @subscriber.logged.clear
     @connection.send(:rename_column_sql, 'bar_baz', 'foo', 'foo2')
-    assert_equal "SCHEMA", @connection.logged[0][1]
+    assert_equal "SCHEMA", @subscriber.logged[0][1]
   ensure
     @connection.execute "DROP TABLE `bar_baz`"
   end
diff --git a/activerecord/test/cases/adapters/mysql2/explain_test.rb b/activerecord/test/cases/adapters/mysql2/explain_test.rb
index 68ed361aeb..1cd356e868 100644
--- a/activerecord/test/cases/adapters/mysql2/explain_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/explain_test.rb
@@ -10,15 +10,15 @@ module ActiveRecord
         def test_explain_for_one_query
           explain = Developer.where(:id => 1).explain
           assert_match %(EXPLAIN for: SELECT `developers`.* FROM `developers`  WHERE `developers`.`id` = 1), explain
-          assert_match %(developers | const), explain
+          assert_match %r(developers |.* const), explain
         end
 
         def test_explain_with_eager_loading
           explain = Developer.where(:id => 1).includes(:audit_logs).explain
           assert_match %(EXPLAIN for: SELECT `developers`.* FROM `developers`  WHERE `developers`.`id` = 1), explain
-          assert_match %(developers | const), explain
+          assert_match %r(developers |.* const), explain
           assert_match %(EXPLAIN for: SELECT `audit_logs`.* FROM `audit_logs`  WHERE `audit_logs`.`developer_id` IN (1)), explain
-          assert_match %(audit_logs | ALL), explain
+          assert_match %r(audit_logs |.* ALL), explain
         end
       end
     end
diff --git a/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb b/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb
index e76617b845..1a82308176 100644
--- a/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb
@@ -2,7 +2,7 @@ require "cases/helper"
 
 class Group < ActiveRecord::Base
   Group.table_name = 'group'
-  belongs_to :select, :class_name => 'Select'
+  belongs_to :select
   has_one :values
 end
 
diff --git a/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb b/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb
index 9ecd901eac..ec73ec35aa 100644
--- a/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb
@@ -4,22 +4,35 @@ module ActiveRecord
   module ConnectionAdapters
     class Mysql2Adapter
       class SchemaMigrationsTest < ActiveRecord::TestCase
-        def test_initializes_schema_migrations_for_encoding_utf8mb4
-          conn = ActiveRecord::Base.connection
+        def test_renaming_index_on_foreign_key
+          connection.add_index "engines", "car_id"
+          connection.execute "ALTER TABLE engines ADD CONSTRAINT fk_engines_cars FOREIGN KEY (car_id) REFERENCES cars(id)"
+
+          connection.rename_index("engines", "index_engines_on_car_id", "idx_renamed")
+          assert_equal ["idx_renamed"], connection.indexes("engines").map(&:name)
+        ensure
+          connection.execute "ALTER TABLE engines DROP FOREIGN KEY fk_engines_cars"
+        end
 
+        def test_initializes_schema_migrations_for_encoding_utf8mb4
           smtn = ActiveRecord::Migrator.schema_migrations_table_name
-          conn.drop_table(smtn) if conn.table_exists?(smtn)
+          connection.drop_table(smtn) if connection.table_exists?(smtn)
 
-          config = conn.instance_variable_get(:@config)
+          config = connection.instance_variable_get(:@config)
           original_encoding = config[:encoding]
 
           config[:encoding] = 'utf8mb4'
-          conn.initialize_schema_migrations_table
+          connection.initialize_schema_migrations_table
 
-          assert conn.column_exists?(smtn, :version, :string, limit: Mysql2Adapter::MAX_INDEX_LENGTH_FOR_UTF8MB4)
+          assert connection.column_exists?(smtn, :version, :string, limit: Mysql2Adapter::MAX_INDEX_LENGTH_FOR_UTF8MB4)
         ensure
           config[:encoding] = original_encoding
         end
+
+        private
+        def connection
+          @connection ||= ActiveRecord::Base.connection
+        end
       end
     end
   end
diff --git a/activerecord/test/cases/adapters/mysql2/schema_test.rb b/activerecord/test/cases/adapters/mysql2/schema_test.rb
index 5db60ff8a0..43c9116b5a 100644
--- a/activerecord/test/cases/adapters/mysql2/schema_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/schema_test.rb
@@ -65,6 +65,15 @@ module ActiveRecord
         assert_nil index_c.using
         assert_equal :fulltext, index_c.type
       end
+
+      def test_drop_temporary_table
+        @connection.transaction do
+          @connection.create_table(:temp_table, temporary: true)
+          # if it doesn't properly say DROP TEMPORARY TABLE, the transaction commit
+          # will complain that no transaction is active
+          @connection.drop_table(:temp_table, temporary: true)
+        end
+      end
     end
   end
 end