Fixed bug #26830: a crash for the query with a subselect containing ROLLUP.

Crash happened because the function get_best_group_min_max detected
joins with ROLLUP incorrectly.

mysql-test/r/olap.result

@@ -645,3 +645,12 @@ a	LENGTH(a)	COUNT(*)
 NULL	NULL	2
 DROP VIEW v1;
 DROP TABLE t1;
+CREATE TABLE t1 (a int, KEY (a));
+INSERT INTO t1 VALUES (3), (1), (4), (1), (3), (1), (1);
+SELECT * FROM (SELECT a, SUM(a) FROM t1 GROUP BY a WITH ROLLUP) as t;
+a	SUM(a)
+1	4
+3	6
+4	4
+NULL	14
+DROP TABLE t1;

mysql-test/t/olap.test

@@ -327,3 +327,18 @@ SELECT * FROM v1;
 
 DROP VIEW v1;
 DROP TABLE t1;
+
+#
+# Bug #26830: derived table with ROLLUP 
+#
+
+CREATE TABLE t1 (a int, KEY (a));
+INSERT INTO t1 VALUES (3), (1), (4), (1), (3), (1), (1);
+
+SELECT * FROM (SELECT a, SUM(a) FROM t1 GROUP BY a WITH ROLLUP) as t;
+
+DROP TABLE t1;
+
+
+
+

sql/opt_range.cc

@@ -7504,7 +7504,7 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree)
   if ((join->tables != 1) ||  /* The query must reference one table. */
       ((!join->group_list) && /* Neither GROUP BY nor a DISTINCT query. */
        (!join->select_distinct)) ||
-      (thd->lex->select_lex.olap == ROLLUP_TYPE)) /* Check (B3) for ROLLUP */
+      (join->select_lex->olap == ROLLUP_TYPE)) /* Check (B3) for ROLLUP */
     DBUG_RETURN(NULL);
   if (table->s->keys == 0)        /* There are no indexes to use. */
     DBUG_RETURN(NULL);