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.

client/mysqltest.c

@@ -996,7 +996,8 @@ int do_sync_with_master2(const char* p)
   if (!(row = mysql_fetch_row(res)))
     die("line %u: empty result in %s", start_lineno, query_buf);
   if (!row[0])
-    die("Error on slave while syncing with master");
+    die("line %u: could not sync with master ('%s' returned NULL)", 
+        start_lineno, query_buf);
   mysql_free_result(res);
   last_result=0;
   if (rpl_parse)

mysql-test/r/rpl_loaddata.result

@@ -25,6 +25,3 @@ drop table t3;
 create table t1(a int, b int, unique(b));
 insert into t1 values(1,10);
 load data infile '../../std_data/rpl_loaddata.dat' into table t1;
-show status like 'slave_running';
-Variable_name	Value
-Slave_running	OFF

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

mysql-test/t/rpl000001.test

@@ -90,8 +90,8 @@ connection master;
 --error 1053;
 reap;
 connection slave;
-sync_with_master;
-#give the slave a chance to exit
+# The SQL slave thread should now have stopped because the query was killed on
+# the master (so it has a non-zero error code in the binlog).
 wait_for_slave_to_stop;
 
 # The following test can't be done because the result of Pos will differ

mysql-test/t/rpl_loaddata.test

@@ -42,9 +42,5 @@ load data infile '../../std_data/rpl_loaddata.dat' into table t1;
 
 save_master_pos;
 connection slave;
-# don't sync_with_master because the slave SQL thread should be stopped because
-# of the error so MASTER_POS_WAIT() will not return; just sleep and hope the
-# slave SQL thread will have had time to stop.
-
-sleep 1;
-show status like 'slave_running';
+# The SQL slave thread should be stopped now.
+wait_for_slave_to_stop;

mysql-test/t/rpl_master_pos_wait.test

@@ -5,5 +5,11 @@ save_master_pos;
 connection slave;
 sync_with_master;
 # Ask for a master log that has certainly not been reached yet
-# timeout= 10 seconds
-select master_pos_wait('master-bin.999999',0,10);
+# timeout= 2 seconds
+select master_pos_wait('master-bin.999999',0,2);
+# Testcase for bug 651 (master_pos_wait() hangs if slave idle and STOP SLAVE).
+send select master_pos_wait('master-bin.999999',0);
+connection slave1;
+stop slave sql_thread;
+connection slave;
+reap;

sql/slave.cc

@@ -2445,8 +2445,17 @@ reconnect done to recover from failed read");
         for no reason, but this function will do a clean read, notice the clean
         value and exit immediately.
       */
-      DBUG_PRINT("info", ("ignore_log_space_limit=%d", (int)
-                          mi->rli.ignore_log_space_limit)); 
+#ifndef DBUG_OFF
+      {
+        char llbuf1[22], llbuf2[22];
+        DBUG_PRINT("info", ("log_space_limit=%s log_space_total=%s \
+ignore_log_space_limit=%d",
+                            llstr(mi->rli.log_space_limit,llbuf1),
+                            llstr(mi->rli.log_space_total,llbuf2),
+                            (int) mi->rli.ignore_log_space_limit)); 
+      }
+#endif
+
       if (mi->rli.log_space_limit && mi->rli.log_space_limit <
 	  mi->rli.log_space_total &&
           !mi->rli.ignore_log_space_limit)