From e851a9eaea77eb896c14b5d57a7acb6221fea2f9 Mon Sep 17 00:00:00 2001
From: "evgen@moonbone.local" <>
Date: Wed, 29 Nov 2006 14:52:11 +0300
Subject: [PATCH] Bug#20327: Marking of a wrong field leads to a wrong result
 on select with view, prepared statement and subquery.

When a field of a view from an outer select is resolved the find_field_in_view
function creates an Item_direct_view_ref object that references the
corresponding view underlying field. After that the view_ref is marked
as a dependent one. While resolving view underlying field it also get
marked as a dependent one due to current_select still points to the subselect.
Marking the view underlying field is wrong and lead to attaching conditions
to a wrong table and thus to the wrong result of the whole statement.

Now mark_select_range_as_dependent() function isn't called for fields from a
view underlying table.
---
 mysql-test/r/ps.result | 18 ++++++++++++++++++
 mysql-test/t/ps.test   | 22 ++++++++++++++++++++++
 sql/sql_base.cc        |  6 ++++++
 3 files changed, 46 insertions(+)

diff --git a/mysql-test/r/ps.result b/mysql-test/r/ps.result
index 048c3ae46d3..2493bd372ea 100644
--- a/mysql-test/r/ps.result
+++ b/mysql-test/r/ps.result
@@ -1379,4 +1379,22 @@ i
 1
 DEALLOCATE PREPARE stmt;
 DROP TABLE t1, t2;
+CREATE TABLE t1 (i INT);
+CREATE VIEW v1 AS SELECT * FROM t1;
+INSERT INTO t1 VALUES (1), (2);
+SELECT t1.i FROM t1 JOIN v1 ON t1.i = v1.i
+WHERE EXISTS (SELECT * FROM t1 WHERE v1.i = 1);
+i
+1
+PREPARE stmt FROM "SELECT t1.i FROM t1 JOIN v1 ON t1.i = v1.i
+WHERE EXISTS (SELECT * FROM t1 WHERE v1.i = 1)";
+EXECUTE stmt;
+i
+1
+EXECUTE stmt;
+i
+1
+DEALLOCATE PREPARE stmt;
+DROP VIEW v1;
+DROP TABLE t1;
 End of 5.0 tests.
diff --git a/mysql-test/t/ps.test b/mysql-test/t/ps.test
index f1e8e77d94e..be77c2533e9 100644
--- a/mysql-test/t/ps.test
+++ b/mysql-test/t/ps.test
@@ -1437,4 +1437,26 @@ DEALLOCATE PREPARE stmt;
 DROP TABLE t1, t2;
 
 
+#
+# BUG#20327: Marking of a wrong field leads to a wrong result on select with
+#            view, prepared statement and subquery.
+#
+CREATE TABLE t1 (i INT);
+CREATE VIEW v1 AS SELECT * FROM t1;
+
+INSERT INTO t1 VALUES (1), (2);
+
+let $query = SELECT t1.i FROM t1 JOIN v1 ON t1.i = v1.i
+             WHERE EXISTS (SELECT * FROM t1 WHERE v1.i = 1);
+eval $query;
+eval PREPARE stmt FROM "$query";
+# Statement execution should return '1'.
+EXECUTE stmt;
+# Check re-execution.
+EXECUTE stmt;
+
+DEALLOCATE PREPARE stmt;
+DROP VIEW v1;
+DROP TABLE t1;
+
 --echo End of 5.0 tests.
diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 3984ceac6a9..314452fac89 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -3303,6 +3303,12 @@ find_field_in_tables(THD *thd, Item_ident *item,
     {
       if (found == WRONG_GRANT)
 	return (Field*) 0;
+
+      /*
+        Only views fields should be marked as dependent, not an underlying
+        fields.
+      */
+      if (!table_ref->belong_to_view)
       {
         SELECT_LEX *current_sel= thd->lex->current_select;
         SELECT_LEX *last_select= table_ref->select_lex;