Merge branch '50-stable' into 51-stable

* 50-stable:
  [test] on MariaDB 10.2+ we're allowed to change default
  [test] skip tests when jdbc/mysql n/a

Author: kares

test/db/mysql/change_column_test.rb

@@ -13,12 +13,12 @@ class MySQLChangeColumnTest < Test::Unit::TestCase
       ActiveRecord::Migration.add_column :people, :about, :string, :default => 'x'
       # NOTE: even in non strict mode MySQL does not allow us add or change
       # text/binary with a default ...
-      if ar_version('4.2')
+      if mariadb_server? && ActiveRecord::Base.connection.database_version >= '10.2'
+        ActiveRecord::Migration.change_column :people, :about, :text
+      else
         assert_raises ActiveRecord::StatementInvalid do
           ActiveRecord::Migration.change_column :people, :about, :text
         end
-      else
-        ActiveRecord::Migration.change_column :people, :about, :text
       end
       ActiveRecord::Migration.add_column :people, :photo, :binary
     end

test/db/mysql/unit_test.rb

@@ -110,7 +110,7 @@ def initialize; end
     end
 
     test 'configuration attempts to load MySQL driver by default' do
-      load_jdbc_mysql
+      skip 'jdbc/mysql not available' if load_jdbc_mysql.nil?
 
       connection_handler = connection_handler_stub
 
@@ -121,7 +121,7 @@ def initialize; end
     end
 
     test 'configuration uses driver_name from Jdbc::MySQL' do
-      load_jdbc_mysql
+      skip 'jdbc/mysql not available' if load_jdbc_mysql.nil?
 
       connection_handler = connection_handler_stub
 
@@ -133,7 +133,7 @@ def initialize; end
     end
 
     test 'configuration sets up properties according to connector/j driver (>= 8.0)' do
-      load_jdbc_mysql
+      skip 'jdbc/mysql not available' if load_jdbc_mysql.nil?
 
       connection_handler = connection_handler_stub
 
@@ -150,6 +150,8 @@ def initialize; end
 
     def load_jdbc_mysql
       require 'jdbc/mysql'
+    rescue LoadError
+      return nil
     end
 
   end