2 bugfixes:

- Bug #985: "Between RESET SLAVE and START SLAVE, SHOW SLAVE STATUS is wrong."
Now RESET SLAVE puts correct info in mi->host etc. A new test rpl_reset_slave
for that.
- Bug #986: "CHANGE MASTER & START SLAVE do not reset error columns in SHOW
SLAVE STATUS". Now these reset the errors.


mysql-test/r/rpl_loaddata.result:
  result update.
mysql-test/t/rpl_loaddata.test:
  Test that RESET SLAVE, START SLAVE and CHANGE MASTER all reset 
  Last_slave_error and Last_slave_errno (columns of SHOW SLAVE STATUS).
  We do it in this test because that's one of tests which have 
  an intentional query error on the slave.
sql/slave.cc:
  As we need TWICE the code to copy command-line options (--master-host etc)
  to mi (we already had it in init_master_info, but we also need it in RESET
  SLAVE to fix bug#985), I make a function of this code.
  And a function to reset Last_slave_error and Last_slave_errno (we need
  it in CHANGE MASTER, RESET SLAVE, and at the start of the SQL thread).
sql/slave.h:
  declarations for new functions.
sql/sql_repl.cc:
  copy --master-host etc to mi in RESET SLAVE, so that SHOW SLAVE STATUS
  shows correct information.

1 files changed, 53 insertions, 0 deletions

diff --git a/mysql-test/t/rpl_loaddata.test b/mysql-test/t/rpl_loaddata.test
index 96a4eb3fb76..0a07dd7549b 100644
--- a/mysql-test/t/rpl_loaddata.test
+++ b/mysql-test/t/rpl_loaddata.test
@@ -6,6 +6,9 @@
 #
 # check if duplicate entries trigger an error (they should unless IGNORE or
 # REPLACE was used on the master) (bug 571).
+#
+# check if START SLAVE, RESET SLAVE, CHANGE MASTER reset Last_slave_error and
+# Last_slave_errno in SHOW SLAVE STATUS (1st and 3rd commands did not: bug 986).
 
 source include/master-slave.inc;
 
@@ -44,3 +47,53 @@ save_master_pos;
 connection slave;
 # The SQL slave thread should be stopped now.
 wait_for_slave_to_stop;
+
+# Skip the bad event and see if error is cleared in SHOW SLAVE STATUS by START
+# SLAVE, even though we are not executing any event (as sql_slave_skip_counter
+# takes us directly to the end of the relay log).
+
+set global sql_slave_skip_counter=1;
+start slave;
+sync_with_master;
+--replace_result $MASTER_MYPORT MASTER_PORT
+show slave status;
+
+# Trigger error again to test CHANGE MASTER
+
+connection master;
+set sql_log_bin=0;
+delete from t1;
+set sql_log_bin=1;
+load data infile '../../std_data/rpl_loaddata.dat' into table t1;
+save_master_pos;
+connection slave;
+# The SQL slave thread should be stopped now.
+wait_for_slave_to_stop;
+
+# CHANGE MASTER and see if error is cleared in SHOW SLAVE STATUS.
+stop slave;
+change master to master_user='test';
+change master to master_user='root';
+--replace_result $MASTER_MYPORT MASTER_PORT
+show slave status;
+
+# Trigger error again to test RESET SLAVE
+
+set global sql_slave_skip_counter=1;
+start slave;
+sync_with_master;
+connection master;
+set sql_log_bin=0;
+delete from t1;
+set sql_log_bin=1;
+load data infile '../../std_data/rpl_loaddata.dat' into table t1;
+save_master_pos;
+connection slave;
+# The SQL slave thread should be stopped now.
+wait_for_slave_to_stop;
+
+# RESET SLAVE and see if error is cleared in SHOW SLAVE STATUS.
+stop slave;
+reset slave;
+--replace_result $MASTER_MYPORT MASTER_PORT
+show slave status;