MySQL: work around ruby-mysql/mysql-ruby inconsistency with mysql.stat. ...

MySQL: work around ruby-mysql/mysql-ruby inconsistency with mysql.stat.  Eliminate usage of mysql.ping because it doesn't guarantee reconnect.  Explicitly close and reopen the connection instead.  References #428.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3216 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

 *SVN*
 
+* MySQL: work around ruby-mysql/mysql-ruby inconsistency with mysql.stat.  Eliminate usage of mysql.ping because it doesn't guarantee reconnect.  Explicitly close and reopen the connection instead.  [Jeremy Kemper]
+
 * Added preliminary support for polymorphic associations [DHH]
 
 * Added preliminary support for join models [DHH]

activerecord/lib/active_record/connection_adapters/mysql_adapter.rb

@@ -155,18 +155,20 @@ def active?
         else
           @connection.query 'select 1'
         end
-        true
+
+        # mysql-ruby doesn't raise an exception when stat fails.
+        if @connection.respond_to?(:errno)
+          @connection.errno.zero?
+        else
+          true
+        end
       rescue Mysql::Error
         false
       end
 
       def reconnect!
-        if @connection.respond_to?(:ping)
-          @connection.ping
-        else
-          @connection.close rescue nil
-          connect
-        end
+        @connection.close rescue nil
+        connect
       end