caching of queries with isammerge tables forbiden using general way

SQL_SELECT_LIMIT as default will be applied only for SELECT statement if there was not explicit LIMIT clause
correct table list passed to class constructor of select_update

1 files changed, 14 insertions, 0 deletions

diff --git a/mysql-test/r/union.result b/mysql-test/r/union.result
index 54bba1fd958..bf8b8df7c65 100644
--- a/mysql-test/r/union.result
+++ b/mysql-test/r/union.result
@@ -936,3 +936,17 @@ select 1 union select 2;
 1
 2
 set sql_select_limit=default;
+create table t1 (a int);
+insert into t1 values (100), (1);
+create table t2 (a int);
+insert into t2 values (100);
+select a from t1 union select a from t2 order by a;
+a
+1
+100
+SET SQL_SELECT_LIMIT=1;
+select a from t1 union select a from t2 order by a;
+a
+1
+drop table t1, t2;
+set sql_select_limit=default;