MDEV-16957: Server crashes in Field_iterator_natural_join::next upon 2nd execution of SP

The problem was that join_columns creation was not finished due to error of notfound column in USING, but next execution tried to use join_columns lists.

Solution is cleanup the lists on error. It can eat memory in statement MEM_ROOT but it is an error and error will be fixed or statement/procedure removed/altered.

Author: sanja-byelkin

mysql-test/r/join.result

@@ -1514,11 +1514,13 @@ ERROR 42S22: Unknown column 'f' in 'from clause'
 DROP TABLE t;
 CREATE TABLE t (f INT);
 CALL p;
-ERROR 42S22: Unknown column 'f' in 'from clause'
+f
 DROP TABLE t;
 CREATE TABLE t (i INT);
 CALL p;
-ERROR 42S22: Unknown column 'f' in 'from clause'
+ERROR 42S22: Unknown column 't1.f' in 'field list'
+CALL p;
+ERROR 42S22: Unknown column 't1.f' in 'field list'
 DROP PROCEDURE p;
 DROP TABLE t;
 CREATE TABLE t1 (a INT, b INT);

mysql-test/r/sp.result

@@ -8055,4 +8055,21 @@ SET S.CLOSE_YN = ''
 where 1=1;
 drop function if exists f1;
 drop table t1,t2;
+#
+# MDEV-16957: Server crashes in Field_iterator_natural_join::next
+# upon 2nd execution of SP
+#
+CREATE TABLE t1 (a INT, b VARCHAR(32));
+CREATE PROCEDURE sp() SELECT * FROM t1 AS t1x JOIN t1 AS t1y USING (c);
+CALL sp;
+ERROR 42S22: Unknown column 'c' in 'from clause'
+CALL sp;
+ERROR 42S22: Unknown column 'c' in 'from clause'
+CALL sp;
+ERROR 42S22: Unknown column 'c' in 'from clause'
+alter table t1 add column c int;
+CALL sp;
+c	a	b	a	b
+DROP PROCEDURE sp;
+DROP TABLE t1;
 # End of 5.5 test

mysql-test/t/join.test

@@ -1185,12 +1185,13 @@ CREATE TABLE t (f INT);
 #
 # The following shouldn't fail as the table is now matching the using
 #
---error ER_BAD_FIELD_ERROR
 CALL p;
 DROP TABLE t;
 CREATE TABLE t (i INT);
 --error ER_BAD_FIELD_ERROR
 CALL p;
+--error ER_BAD_FIELD_ERROR
+CALL p;
 DROP PROCEDURE p;
 DROP TABLE t;
 

mysql-test/t/sp.test

@@ -9353,4 +9353,25 @@ where 1=1;
 drop function if exists f1;
 drop table t1,t2;
 
+--echo #
+--echo # MDEV-16957: Server crashes in Field_iterator_natural_join::next
+--echo # upon 2nd execution of SP
+--echo #
+
+CREATE TABLE t1 (a INT, b VARCHAR(32));
+CREATE PROCEDURE sp() SELECT * FROM t1 AS t1x JOIN t1 AS t1y USING (c);
+--error ER_BAD_FIELD_ERROR
+CALL sp;
+--error ER_BAD_FIELD_ERROR
+CALL sp;
+--error ER_BAD_FIELD_ERROR
+CALL sp;
+alter table t1 add column c int;
+CALL sp;
+
+# Cleanup
+DROP PROCEDURE sp;
+DROP TABLE t1;
+
+
 --echo # End of 5.5 test

sql/sql_base.cc

@@ -7764,10 +7764,22 @@ store_natural_using_join_columns(THD *thd, TABLE_LIST *natural_using_join,
 
   result= FALSE;
 
-err:
   if (arena)
     thd->restore_active_arena(arena, &backup);
   DBUG_RETURN(result);
+
+err:
+  /*
+     Actually we failed to build join columns list, so we have to
+     clear it to avoid problems with half-build join on next run.
+     The list was created in mark_common_columns().
+   */
+  table_ref_1->remove_join_columns();
+  table_ref_2->remove_join_columns();
+
+  if (arena)
+    thd->restore_active_arena(arena, &backup);
+  DBUG_RETURN(TRUE);
 }
 
 

sql/table.h

@@ -2184,6 +2184,16 @@ struct TABLE_LIST
   } 
   void set_lock_type(THD* thd, enum thr_lock_type lock);
 
+  void remove_join_columns()
+  {
+    if (join_columns)
+    {
+      join_columns->empty();
+      join_columns= NULL;
+      is_join_columns_complete= FALSE;
+    }
+  }
+
 private:
   bool prep_check_option(THD *thd, uint8 check_opt_type);
   bool prep_where(THD *thd, Item **conds, bool no_where_clause);