temporary commit - need to pull Monty's changes

mysql-test/t/rpl000001.test:
  modified test to break current replicatioin on a large log with a large lag 
  in slave thread between append and read of the relay log
mysys/mf_iocache.c:
  fixed one bug in IO_CACHE but there is another one not fixed yet
sql/slave.cc:
  fixed bug in 3.23 master replication

1 files changed, 20 insertions, 3 deletions

diff --git a/mysql-test/t/rpl000001.test b/mysql-test/t/rpl000001.test
index 57b81cb9e33..597b1c69b1e 100644
--- a/mysql-test/t/rpl000001.test
+++ b/mysql-test/t/rpl000001.test
@@ -27,21 +27,38 @@ sync_with_master;
 connection master;
 reset master;
 connection slave;
+slave stop;
 reset slave;
 
 connection master;
 drop table if exists t1,t2;
 create table t1(n int);
-let $1=10;
+#we want the log to exceed 16K to test deal with the log that is bigger than
+#IO_SIZE
+let $1=5000;
+disable_query_log;
 while ($1)
 {
- eval insert into t1 values($1);
+ eval insert into t1 values($1+get_lock("hold_slave",10)*0);
  dec $1;
 }
+enable_query_log;
+
+#try to cause a large relay log lag on the slave 
+connection slave;
+select get_lock("hold_slave",10);
+slave start;
+#hope this is long enough for I/O thread to fetch over 16K relay log data
+sleep 1;
+select release_lock("hold_slave");
+unlock tables;
+
+connection master;
 create table t2(id int);
 insert into t2 values(connection_id());
 save_master_pos;
 
+
 connection master1;
 #avoid generating result
 create temporary table t1_temp(n int);
@@ -60,7 +77,7 @@ reap;
 connection slave;
 sync_with_master ;
 #give the slave a chance to exit
-sleep 0.5;
+wait_for_slave_to_stop;
 
 # The following test can't be done because the result of Pos will differ
 # on different computers