MDEV-9084 Calling a stored function from a nested select from tempora…

…ry table causes unpredictable behavior

Cherry-pick: f4a0af070ce49abae60040f6f32e1074309c27fb
Author: Dmitry Lenev <dmitry.lenev@oracle.com>
Date:   Mon Jul 25 16:06:52 2016 +0300

  Fix for bug #16672723 "CAN'T FIND TEMPORARY TABLE".

  Attempt to execute prepared CREATE TABLE SELECT statement which used
  temporary table in the subquery in FROM clause and stored function
  failed with unwarranted ER_NO_SUCH_TABLE error. The same happened
  when such statement was used in stored procedure and this procedure
  was re-executed.

  The problem occurred because execution of such prepared statement/its
  re-execution as part of stored procedure incorrectly set
  Query_table_list::query_tables_own_last marker, indicating the last
  table which is directly used by statement. As result temporary table
  used in the subquery was treated as indirectly used/belonging to
  prelocking list and was not pre-opened by open_temporary_tables()
  call before statement execution. Thus causing ER_NO_SUCH_TABLE errors
  since our code assumes that temporary tables need to be correctly
  pre-opened before statement execution.

  This problem became visible only in version 5.6 after patches related to
  bug 11746602/27480 "EXTEND CREATE TEMPORARY TABLES PRIVILEGE TO ALLOW
  TEMP TABLE OPERATIONS" since they have introduced pre-opening of temporary
  tables for statements.

  Incorrect setting of Query_table_list::query_tables_own_last happened
  in LEX::first_lists_tables_same() method which is called by CREATE TABLE
  SELECT implementation as part of LEX::unlink_first_table(), which temporary
  excludes table list element for table being created from the query table
  list before handling SELECT part.

  LEX::first_lists_tables_same() tries to ensure that global table list of
  the statement starts with the first table list element from the first
  statement select. To do this it moves such table list element to the head
  of the global table list. If this table happens to be last directly-used
  table for the statement, query_tables_own_last marker is pointing to it.
  Since this marker was not updated when table list element was moved we
  ended up with all tables except the first table separated by it as if
  they were not directly used by statement (i.e. belonged to prelocked
  tables list).

  This fix changes code of LEX::first_lists_tables_same() to update
  query_tables_own_last marker in cases when it points to the table
  being moved. It is set to the table which precedes table being moved
  in this case.

mysql-test/r/sp-prelocking.result

@@ -340,3 +340,26 @@ f1()
 DROP FUNCTION f1;
 DROP VIEW v1;
 DROP TABLE t1,t2;
+#
+# Bug #16672723 "CAN'T FIND TEMPORARY TABLE".
+#
+CREATE FUNCTION f1() RETURNS INT RETURN 1;
+CREATE TEMPORARY TABLE tmp1(a INT);
+PREPARE stmt1 FROM "CREATE TEMPORARY TABLE tmp2 AS SELECT b FROM (SELECT f1() AS b FROM tmp1) AS t";
+# The below statement failed before the fix.
+EXECUTE stmt1;
+DROP TEMPORARY TABLES tmp1, tmp2;
+DEALLOCATE PREPARE stmt1;
+DROP FUNCTION f1;
+create procedure sp1()
+begin
+drop table if exists t1, t2;
+create temporary table t1 select 1 v;
+create table t2 (col varchar(45)) select distinct col from (select sf1() as col from t1) t;
+end$$
+create function sf1() returns text return 'blah';
+call test.sp1();
+call test.sp1();
+drop procedure sp1;
+drop function sf1;
+drop table t2;

mysql-test/t/sp-prelocking.test

@@ -414,3 +414,33 @@ SELECT f1();
 DROP FUNCTION f1;
 DROP VIEW v1;
 DROP TABLE t1,t2;
+
+--echo #
+--echo # Bug #16672723 "CAN'T FIND TEMPORARY TABLE".
+--echo #
+CREATE FUNCTION f1() RETURNS INT RETURN 1;
+CREATE TEMPORARY TABLE tmp1(a INT);
+PREPARE stmt1 FROM "CREATE TEMPORARY TABLE tmp2 AS SELECT b FROM (SELECT f1() AS b FROM tmp1) AS t";
+--echo # The below statement failed before the fix.
+EXECUTE stmt1;
+DROP TEMPORARY TABLES tmp1, tmp2;
+DEALLOCATE PREPARE stmt1;
+DROP FUNCTION f1;
+
+#
+# MDEV-9084 Calling a stored function from a nested select from temporary table causes unpredictable behavior
+#
+delimiter $$;
+create procedure sp1()
+begin
+  drop table if exists t1, t2;
+  create temporary table t1 select 1 v;
+  create table t2 (col varchar(45)) select distinct col from (select sf1() as col from t1) t;
+end$$
+delimiter ;$$
+create function sf1() returns text return 'blah';
+call test.sp1();
+call test.sp1();
+drop procedure sp1;
+drop function sf1;
+drop table t2;

sql/sql_lex.cc

@@ -3158,6 +3158,9 @@ void LEX::first_lists_tables_same()
     if (query_tables_last == &first_table->next_global)
       query_tables_last= first_table->prev_global;
 
+    if (query_tables_own_last == &first_table->next_global)
+      query_tables_own_last= first_table->prev_global;
+
     if ((next= *first_table->prev_global= first_table->next_global))
       next->prev_global= first_table->prev_global;
     /* include in new place */