[master] Merge branch 'trac4281'

diff --cc src/lib/dhcpsrv/mysql_connection.cc
index e26c2332db04de3c8fd8816d9a267cbf30a0bf43,432805c34e2ccc346435d76d0acd0f3be0ef0f97..30de103d536be0797ec0e2ebf2d24df3a3994e7c
--- 1/src/lib/dhcpsrv/mysql_connection.cc
--- 2/src/lib/dhcpsrv/mysql_connection.cc
+++ b/src/lib/dhcpsrv/mysql_connection.cc
@@@ -29,8 -27,27 +29,28 @@@ const my_bool MLM_TRUE = 1
  const int MLM_MYSQL_FETCH_SUCCESS = 0;
  const int MLM_MYSQL_FETCH_FAILURE = 1;
  
 +const int MYSQL_DEFAULT_CONNECTION_TIMEOUT = 5;       // seconds
  
+ MySqlTransaction::MySqlTransaction(MySqlConnection& conn)
+     : conn_(conn), committed_(false) {
+     conn_.startTransaction();
+ }
+ 
+ MySqlTransaction::~MySqlTransaction() {
+     // Rollback if the MySqlTransaction::commit wasn't explicitly
+     // called.
+     if (!committed_) {
+         conn_.rollback();
+     }
+ }
+ 
+ void
+ MySqlTransaction::commit() {
+     conn_.commit();
+     committed_ = true;
+ }
+ 
+ 
  // Open the database using the parameters passed to the constructor.
  
  void

diff --cc src/lib/dhcpsrv/mysql_host_data_source.cc
Simple merge

diff --cc src/lib/dhcpsrv/parsers/dhcp_parsers.cc
Simple merge

diff --cc src/lib/dhcpsrv/tests/generic_host_data_source_unittest.cc
Simple merge

diff --cc src/lib/dhcpsrv/tests/mysql_host_data_source_unittest.cc
Simple merge