Fix for nightly build test failure (test update).

More messages.
Testcase for bug 651.


client/mysqltest.c:
  More explicit error message if MASTER_POS_WAIT() returns NULL.
mysql-test/r/rpl_loaddata.result:
  result update
mysql-test/r/rpl_master_pos_wait.result:
  result update
mysql-test/t/rpl000001.test:
  sync_with_master (=MASTER_POS_WAIT()) was called when we could expect the SQL slave thread had stopped.
  As I yesterday changed code so that "SQL thread stops => MASTER_POS_WAIT() returns NULL immediately" (bugfix),
  sync_with_master received NULL (on build.mysql.com, not on my machine; this is a question of milliseconds,
  if the slave server will process MASTER_POS_WAIT() before or after the slave SQL thread has stopped), and
  in mysqltest.c, sync_with_master complained that it could not sync.
  So I just remove this sync_with_master, which does not make sense anymore: we just wait for the slave SQL
  thread to stop.
mysql-test/t/rpl_loaddata.test:
  Discovered we had wait_for_slave_to_stop, so used it as it automates things.
mysql-test/t/rpl_master_pos_wait.test:
  Discovered we had 'send' to send a query without waiting for the resultn so could had a testcase for bug 651.
  Shorter timeouts as there is no risk the position is reached.
sql/slave.cc:
  A longer DBUG_PRINT.

1 files changed, 6 insertions, 2 deletions

diff --git a/mysql-test/r/rpl_master_pos_wait.result b/mysql-test/r/rpl_master_pos_wait.result
index 22c7aef621c..cb6ee31a54d 100644
--- a/mysql-test/r/rpl_master_pos_wait.result
+++ b/mysql-test/r/rpl_master_pos_wait.result
@@ -4,6 +4,10 @@ reset master;
 reset slave;
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
 slave start;
-select master_pos_wait('master-bin.999999',0,10);
-master_pos_wait('master-bin.999999',0,10)
+select master_pos_wait('master-bin.999999',0,2);
+master_pos_wait('master-bin.999999',0,2)
 -1
+ select master_pos_wait('master-bin.999999',0);
+stop slave sql_thread;
+master_pos_wait('master-bin.999999',0)
+NULL