[mysql] allow encoding to be server-detected (using encoding: false)

due compatibility we still default to `encoding: utf8` if not set (fixes #481)

Author: kares

lib/arjdbc/mysql/connection_methods.rb

@@ -25,8 +25,9 @@ def mysql_connection(config)
     properties = ( config[:properties] ||= {} )
     properties['zeroDateTimeBehavior'] ||= 'convertToNull'
     properties['jdbcCompliantTruncation'] ||= 'false'
-    properties['useUnicode'] ||= 'true'
-    properties['characterEncoding'] = config[:encoding] || 'utf8'
+    properties['useUnicode'] = 'true' unless properties.key?('useUnicode') # otherwise platform default
+    encoding = config.key?(:encoding) ? config[:encoding] : 'utf8'
+    properties['characterEncoding'] = encoding if encoding
 
     jdbc_connection(config)
   end

test/simple.rb

@@ -1260,7 +1260,8 @@ module MultibyteTestMethods
     def setup
       super
       config = ActiveRecord::Base.connection.config
-      jdbc_driver = ActiveRecord::ConnectionAdapters::JdbcDriver.new(config[:driver])
+      properties = config[:properties] || {}
+      jdbc_driver = ActiveRecord::ConnectionAdapters::JdbcDriver.new(config[:driver], properties)
       @java_connection = jdbc_driver.connection(config[:url], config[:username], config[:password])
       @java_connection.setAutoCommit(true)
     end