7 files changed, 95 insertions, 6 deletions
diff --git a/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb b/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb
new file mode 100644
index 0000000000..4efd728754
--- /dev/null
+++ b/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb
@@ -0,0 +1,44 @@
+require "cases/helper"
+
+class Mysql2AdapterTest < ActiveRecord::Mysql2TestCase
+  def setup
+    @conn = ActiveRecord::Base.connection
+  end
+
+  def test_columns_for_distinct_zero_orders
+    assert_equal "posts.id",
+      @conn.columns_for_distinct("posts.id", [])
+  end
+
+  def test_columns_for_distinct_one_order
+    assert_equal "posts.id, posts.created_at AS alias_0",
+      @conn.columns_for_distinct("posts.id", ["posts.created_at desc"])
+  end
+
+  def test_columns_for_distinct_few_orders
+    assert_equal "posts.id, posts.created_at AS alias_0, posts.position AS alias_1",
+      @conn.columns_for_distinct("posts.id", ["posts.created_at desc", "posts.position asc"])
+  end
+
+  def test_columns_for_distinct_with_case
+    assert_equal(
+      'posts.id, CASE WHEN author.is_active THEN UPPER(author.name) ELSE UPPER(author.email) END AS alias_0',
+      @conn.columns_for_distinct('posts.id',
+        ["CASE WHEN author.is_active THEN UPPER(author.name) ELSE UPPER(author.email) END"])
+    )
+  end
+
+  def test_columns_for_distinct_blank_not_nil_orders
+    assert_equal "posts.id, posts.created_at AS alias_0",
+      @conn.columns_for_distinct("posts.id", ["posts.created_at desc", "", "   "])
+  end
+
+  def test_columns_for_distinct_with_arel_order
+    order = Object.new
+    def order.to_sql
+      "posts.created_at desc"
+    end
+    assert_equal "posts.id, posts.created_at AS alias_0",
+      @conn.columns_for_distinct("posts.id", [order])
+  end
+end
diff --git a/activerecord/test/cases/adapters/mysql2/sp_test.rb b/activerecord/test/cases/adapters/mysql2/sp_test.rb
index cdaa2cca44..4197ba45f1 100644
--- a/activerecord/test/cases/adapters/mysql2/sp_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/sp_test.rb
@@ -22,6 +22,12 @@ class Mysql2StoredProcedureTest < ActiveRecord::Mysql2TestCase
     assert @connection.active?, "Bad connection use by 'Mysql2Adapter.select_rows'"
   end
 
+  def test_multi_results_from_select_one
+    row = @connection.select_one('CALL topics(1);')
+    assert_equal 'David', row['author_name']
+    assert @connection.active?, "Bad connection use by 'Mysql2Adapter.select_one'"
+  end
+
   def test_multi_results_from_find_by_sql
     topics = Topic.find_by_sql 'CALL topics(3);'
     assert_equal 3, topics.size
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index f343a15317..ba3e16bdb2 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -1252,6 +1252,7 @@ class BasicsTest < ActiveRecord::TestCase
     original_logger = ActiveRecord::Base.logger
     log = StringIO.new
     ActiveRecord::Base.logger = ActiveSupport::Logger.new(log)
+    ActiveRecord::Base.logger.level = Logger::DEBUG
     ActiveRecord::Base.benchmark("Logging", :level => :debug, :silence => false)  { ActiveRecord::Base.logger.debug "Quiet" }
     assert_match(/Quiet/, log.string)
   ensure
diff --git a/activerecord/test/cases/column_definition_test.rb b/activerecord/test/cases/column_definition_test.rb
index da0d7f5195..783a374116 100644
--- a/activerecord/test/cases/column_definition_test.rb
+++ b/activerecord/test/cases/column_definition_test.rb
@@ -49,6 +49,16 @@ module ActiveRecord
           assert_equal "a", varbinary_column.default
         end
 
+        def test_should_be_empty_string_default_for_mysql_binary_data_types
+          type = SqlTypeMetadata.new(type: :binary, sql_type: "binary(1)")
+          binary_column = AbstractMysqlAdapter::Column.new("title", "", type, false)
+          assert_equal "", binary_column.default
+
+          type = SqlTypeMetadata.new(type: :binary, sql_type: "varbinary")
+          varbinary_column = AbstractMysqlAdapter::Column.new("title", "", type, false)
+          assert_equal "", varbinary_column.default
+        end
+
         def test_should_not_set_default_for_blob_and_text_data_types
           assert_raise ArgumentError do
             AbstractMysqlAdapter::Column.new("title", "a", SqlTypeMetadata.new(sql_type: "blob"))
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index 9f90ab79a1..75a74c052d 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -19,7 +19,7 @@ require 'models/car'
 require 'models/tyre'
 
 class FinderTest < ActiveRecord::TestCase
-  fixtures :companies, :topics, :entrants, :developers, :developers_projects, :posts, :comments, :accounts, :authors, :customers, :categories, :categorizations, :cars
+  fixtures :companies, :topics, :entrants, :developers, :developers_projects, :posts, :comments, :accounts, :authors, :author_addresses, :customers, :categories, :categorizations, :cars
 
   def test_find_by_id_with_hash
     assert_raises(ActiveRecord::StatementInvalid) do
@@ -993,10 +993,13 @@ class FinderTest < ActiveRecord::TestCase
   end
 
   def test_find_with_order_on_included_associations_with_construct_finder_sql_for_association_limiting_and_is_distinct
-    assert_equal 2, Post.includes(authors: :author_address).order('author_addresses.id DESC ').limit(2).to_a.size
+    assert_equal 2, Post.includes(authors: :author_address).
+      where.not(author_addresses: { id: nil }).
+      order('author_addresses.id DESC').limit(2).to_a.size
 
     assert_equal 3, Post.includes(author: :author_address, authors: :author_address).
-                              order('author_addresses_authors.id DESC ').limit(3).to_a.size
+      where.not(author_addresses_authors: { id: nil }).
+      order('author_addresses_authors.id DESC').limit(3).to_a.size
   end
 
   def test_find_with_nil_inside_set_passed_for_one_attribute
diff --git a/activerecord/test/cases/invalid_connection_test.rb b/activerecord/test/cases/invalid_connection_test.rb
index c26623e3ca..a16b52751a 100644
--- a/activerecord/test/cases/invalid_connection_test.rb
+++ b/activerecord/test/cases/invalid_connection_test.rb
@@ -1,5 +1,6 @@
 require "cases/helper"
 
+if current_adapter?(:Mysql2Adapter)
 class TestAdapterWithInvalidConnection < ActiveRecord::TestCase
   self.use_transactional_tests = false
 
@@ -20,3 +21,4 @@ class TestAdapterWithInvalidConnection < ActiveRecord::TestCase
     assert_equal "#{Bird.name} (call '#{Bird.name}.connection' to establish a connection)", Bird.inspect
   end
 end
+end
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index 7149c7d072..0638edacbd 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -111,15 +111,38 @@ class RelationTest < ActiveRecord::TestCase
 
   def test_loaded_first
     topics = Topic.all.order('id ASC')
+    topics.to_a # force load
 
-    assert_queries(1) do
-      topics.to_a # force load
-      2.times { assert_equal "The First Topic", topics.first.title }
+    assert_no_queries do
+      assert_equal "The First Topic", topics.first.title
     end
 
     assert topics.loaded?
   end
 
+  def test_loaded_first_with_limit
+    topics = Topic.all.order('id ASC')
+    topics.to_a # force load
+
+    assert_no_queries do
+      assert_equal ["The First Topic",
+                    "The Second Topic of the day"], topics.first(2).map(&:title)
+    end
+
+    assert topics.loaded?
+  end
+
+  def test_first_get_more_than_available
+    topics = Topic.all.order('id ASC')
+    unloaded_first = topics.first(10)
+    topics.to_a # force load
+
+    assert_no_queries do
+      loaded_first = topics.first(10)
+      assert_equal unloaded_first, loaded_first
+    end
+  end
+
   def test_reload
     topics = Topic.all