Allow using a different socket to test mysql

Author: rafaelfranca

activerecord/Rakefile

@@ -197,7 +197,7 @@ namespace :db do
   namespace :mysql do
     connection_arguments = lambda do |connection_name|
       config = ARTest.config["connections"]["mysql2"][connection_name]
-      ["--user=#{config["username"]}", "--password=#{config["password"]}", ("--host=#{config["host"]}" if config["host"])].join(" ")
+      ["--user=#{config["username"]}", "--password=#{config["password"]}", ("--host=#{config["host"]}" if config["host"]), ("--socket=#{config["socket"]}" if config["socket"])].join(" ")
     end
 
     desc "Build the MySQL test databases"

activerecord/test/config.example.yml

@@ -45,6 +45,9 @@ connections:
 <% end %>
 <% if ENV['MYSQL_HOST'] %>
       host: <%= ENV['MYSQL_HOST'] %>
+<% end %>
+<% if ENV['MYSQL_SOCK'] %>
+      socket: "<%= ENV['MYSQL_SOCK'] %>"
 <% end %>
     arunit2:
       username: rails
@@ -56,6 +59,9 @@ connections:
 <% if ENV['MYSQL_HOST'] %>
       host: <%= ENV['MYSQL_HOST'] %>
 <% end %>
+<% if ENV['MYSQL_SOCK'] %>
+      socket: "<%= ENV['MYSQL_SOCK'] %>"
+<% end %>
 
   oracle:
      arunit: