Fix a race condition in the PBXT test for MAX_JOIN_SIZE in select_safe.test

The statistics after a sequence of inserts/deletes are updated asynchronously
in PBXT, causing unpredictable test results. Fix by running the test on a
fresh copy of the table with no deletes performed, to get stable results.

mysql-test/suite/pbxt/r/select_safe.result

-drop table if exists t1;
+drop table if exists t1,t2;
 SET SQL_SAFE_UPDATES=1,SQL_SELECT_LIMIT=4, SQL_MAX_JOIN_SIZE=9;
 create table t1 (a int auto_increment primary key, b char(20));
 insert into t1 values(1,"test");
@@ -13,10 +13,12 @@ a	b
 1	test
 2	test2
 update t1 set b="a" where a=1;
-analyze table t1;
+create table t2 like t1;
+insert into t2 select * from t1;
+analyze table t2;
 Table	Op	Msg_type	Msg_text
-test.t1	analyze	status	OK
-select 1 from t1,t1 as t2,t1 as t3;
+test.t2	analyze	status	OK
+select 1 from t2 as t1,t2,t2 as t3;
 1
 1
 1
@@ -77,7 +79,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	b	NULL	NULL	NULL	21	
 1	SIMPLE	t2	ref	b	b	21	test.t1.b	1	Using where
 SET MAX_SEEKS_FOR_KEY=DEFAULT;
-drop table t1;
+drop table t1, t2;
 create table t1 (a int);
 insert into t1 values (1),(2),(3),(4),(5);
 insert into t1 select * from t1;

mysql-test/suite/pbxt/t/select_safe.test

@@ -3,7 +3,7 @@
 #
 
 --disable_warnings
-drop table if exists t1;
+drop table if exists t1,t2;
 --enable_warnings
 
 SET SQL_SAFE_UPDATES=1,SQL_SELECT_LIMIT=4, SQL_MAX_JOIN_SIZE=9;
@@ -15,8 +15,13 @@ delete from t1 where a=1;
 insert into t1 values(1,"test"),(2,"test2");
 SELECT SQL_BUFFER_RESULT * from t1 order by a; # PBXT required for consistent result
 update t1 set b="a" where a=1;
-analyze table t1; # PBXT: required to get the correct COUNT(*)
-select 1 from t1,t1 as t2,t1 as t3;
+
+# Test MAX_JOIN_SIZE in a fresh table, as insert/delete combination
+# makes PBXT statistics non-deterministic
+create table t2 like t1;
+insert into t2 select * from t1;
+analyze table t2; # PBXT: required to get the correct COUNT(*)
+select 1 from t2 as t1,t2,t2 as t3;
 
 # The following should give errors:
 --error 1175
@@ -64,7 +69,7 @@ set MAX_SEEKS_FOR_KEY=1;
 explain select STRAIGHT_JOIN * from t1,t1 as t2 where t1.b=t2.b;
 SET MAX_SEEKS_FOR_KEY=DEFAULT;
 
-drop table t1;
+drop table t1, t2;
 
 # BUG#8726
 create table t1 (a int);