Fixed LP bug #879871.

The function add_ref_to_table_cond missed updating the value of
join_tab->pre_idx_push_select_cond after having updated the value
of join_tab->select->pre_idx_push_select_cond.

mysql-test/include/icp_tests.inc

@@ -724,3 +724,23 @@ SELECT t1.b, t1.c FROM t1, t2 WHERE t1.a = t2.a AND t1.b != 0
   HAVING t1.c != 5 ORDER BY t1.c;
 
 DROP TABLE t1,t2;
+
+--echo #
+--echo # Bug#879871: InnoDB: possible ICP + GROUP BY primary index  
+--echo #
+
+CREATE TABLE t1 (
+  a int NOT NULL, b int, c varchar(1), d varchar(1),
+ PRIMARY KEY (a), KEY c (c,b)
+);
+INSERT INTO t1 VALUES (10,8,'g','g');
+
+SET SESSION optimizer_switch='index_condition_pushdown=off';
+SELECT a FROM t1 WHERE c IS NULL AND d IS NOT NULL GROUP BY 1;
+
+SET SESSION optimizer_switch='index_condition_pushdown=on';
+SELECT a FROM t1 WHERE c IS NULL AND d IS NOT NULL GROUP BY 1;
+
+DROP TABLE t1;
+
+

mysql-test/r/innodb_icp.result

@@ -686,5 +686,20 @@ HAVING t1.c != 5 ORDER BY t1.c;
 b	c
 1	4
 DROP TABLE t1,t2;
+#
+# Bug#879871: InnoDB: possible ICP + GROUP BY primary index  
+#
+CREATE TABLE t1 (
+a int NOT NULL, b int, c varchar(1), d varchar(1),
+PRIMARY KEY (a), KEY c (c,b)
+);
+INSERT INTO t1 VALUES (10,8,'g','g');
+SET SESSION optimizer_switch='index_condition_pushdown=off';
+SELECT a FROM t1 WHERE c IS NULL AND d IS NOT NULL GROUP BY 1;
+a
+SET SESSION optimizer_switch='index_condition_pushdown=on';
+SELECT a FROM t1 WHERE c IS NULL AND d IS NOT NULL GROUP BY 1;
+a
+DROP TABLE t1;
 set optimizer_switch=@innodb_icp_tmp;
 set storage_engine= @save_storage_engine;

mysql-test/r/maria_icp.result

@@ -692,5 +692,20 @@ HAVING t1.c != 5 ORDER BY t1.c;
 b	c
 1	4
 DROP TABLE t1,t2;
+#
+# Bug#879871: InnoDB: possible ICP + GROUP BY primary index  
+#
+CREATE TABLE t1 (
+a int NOT NULL, b int, c varchar(1), d varchar(1),
+PRIMARY KEY (a), KEY c (c,b)
+);
+INSERT INTO t1 VALUES (10,8,'g','g');
+SET SESSION optimizer_switch='index_condition_pushdown=off';
+SELECT a FROM t1 WHERE c IS NULL AND d IS NOT NULL GROUP BY 1;
+a
+SET SESSION optimizer_switch='index_condition_pushdown=on';
+SELECT a FROM t1 WHERE c IS NULL AND d IS NOT NULL GROUP BY 1;
+a
+DROP TABLE t1;
 set storage_engine= @save_storage_engine;
 set optimizer_switch=@maria_icp_tmp;

mysql-test/r/myisam_icp.result

@@ -690,6 +690,21 @@ HAVING t1.c != 5 ORDER BY t1.c;
 b	c
 1	4
 DROP TABLE t1,t2;
+#
+# Bug#879871: InnoDB: possible ICP + GROUP BY primary index  
+#
+CREATE TABLE t1 (
+a int NOT NULL, b int, c varchar(1), d varchar(1),
+PRIMARY KEY (a), KEY c (c,b)
+);
+INSERT INTO t1 VALUES (10,8,'g','g');
+SET SESSION optimizer_switch='index_condition_pushdown=off';
+SELECT a FROM t1 WHERE c IS NULL AND d IS NOT NULL GROUP BY 1;
+a
+SET SESSION optimizer_switch='index_condition_pushdown=on';
+SELECT a FROM t1 WHERE c IS NULL AND d IS NOT NULL GROUP BY 1;
+a
+DROP TABLE t1;
 drop table if exists t0, t1, t1i, t1m;
 #
 # BUG#826935 Assertion `!table || (!table->read_set || bitmap_is_set(table->read_set, field_index))' failed

sql/sql_select.cc

@@ -19969,7 +19969,8 @@ static bool add_ref_to_table_cond(THD *thd, JOIN_TAB *join_tab)
       Item *new_cond= and_conds(cond_copy, join_tab->select->pre_idx_push_select_cond);
       if (!new_cond->fixed && new_cond->fix_fields(thd, &new_cond))
         error= 1;
-      join_tab->select->pre_idx_push_select_cond= new_cond;
+      join_tab->pre_idx_push_select_cond=
+        join_tab->select->pre_idx_push_select_cond= new_cond;
     }
     join_tab->set_select_cond(cond, __LINE__);
   }