Fixed bug #27827.

ON conditions from JOIN expression were ignored at CHECK OPTION
check when updating a multi-table view with CHECK OPTION.

The st_table_list::prep_check_option function has been
modified to to take into account ON conditions at CHECK OPTION check
It was also changed to build the check option condition only once
for any update used in PS/SP.


sql/table.h:
  Fixed bug #27827.
  The st_table_list::check_option_processed variable has been added
  to build the check option condition only once for any update used
  in PS/SP.
sql/table.cc:
  Fixed bug #27827.
  The st_table_list::prep_check_option function has been
  modified to to take into account ON conditions at CHECK OPTION check
  It was also changed to build the check option condition only once
  for any update used in PS/SP.
mysql-test/t/view.test:
  Updated test case for bug #27827.
mysql-test/r/view.result:
  Updated test case for bug #27827.

mysql-test/r/view.result

@@ -3367,4 +3367,65 @@ SHOW CREATE VIEW v1;
 View	Create View
 v1	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1` AS select cast(1.23456789 as decimal(8,0)) AS `col`
 DROP VIEW v1;
+CREATE TABLE t1 (a1 INT, c INT DEFAULT 0);
+CREATE TABLE t2 (a2 INT);
+CREATE TABLE t3 (a3 INT);
+CREATE TABLE t4 (a4 INT);
+INSERT INTO t1 (a1) VALUES (1),(2);
+INSERT INTO t2 (a2) VALUES (1),(2);
+INSERT INTO t3 (a3) VALUES (1),(2);
+INSERT INTO t4 (a4) VALUES (1),(2);
+CREATE VIEW v1 AS
+SELECT t1.a1, t1.c FROM t1 JOIN t2 ON t1.a1=t2.a2 AND t1.c < 3
+WITH CHECK OPTION;
+SELECT * FROM v1;
+a1	c
+1	0
+2	0
+UPDATE v1 SET c=3;
+ERROR HY000: CHECK OPTION failed 'test.v1'
+PREPARE t FROM 'UPDATE v1 SET c=3';
+EXECUTE t;
+ERROR HY000: CHECK OPTION failed 'test.v1'
+EXECUTE t;
+ERROR HY000: CHECK OPTION failed 'test.v1'
+INSERT INTO v1(a1, c) VALUES (3, 3);
+ERROR HY000: CHECK OPTION failed 'test.v1'
+UPDATE v1 SET c=1 WHERE a1=1;
+SELECT * FROM v1;
+a1	c
+1	1
+2	0
+SELECT * FROM t1;
+a1	c
+1	1
+2	0
+CREATE VIEW v2 AS SELECT t1.a1, t1.c
+FROM (t1 JOIN t2 ON t1.a1=t2.a2 AND t1.c < 3)
+JOIN (t3 JOIN t4 ON t3.a3=t4.a4)
+ON t2.a2=t3.a3 WITH CHECK OPTION;
+SELECT * FROM v2;
+a1	c
+1	1
+2	0
+UPDATE v2 SET c=3;
+ERROR HY000: CHECK OPTION failed 'test.v2'
+PREPARE t FROM 'UPDATE v2 SET c=3';
+EXECUTE t;
+ERROR HY000: CHECK OPTION failed 'test.v2'
+EXECUTE t;
+ERROR HY000: CHECK OPTION failed 'test.v2'
+INSERT INTO v2(a1, c) VALUES (3, 3);
+ERROR HY000: CHECK OPTION failed 'test.v2'
+UPDATE v2 SET c=2 WHERE a1=1;
+SELECT * FROM v2;
+a1	c
+1	2
+2	0
+SELECT * FROM t1;
+a1	c
+1	2
+2	0
+DROP VIEW v1,v2;
+DROP TABLE t1,t2,t3,t4;
 End of 5.0 tests.

mysql-test/t/view.test

@@ -3233,4 +3233,56 @@ CREATE VIEW v1 AS SELECT CAST(1.23456789 AS DECIMAL(8,0)) AS col;
 SHOW CREATE VIEW v1;
 DROP VIEW v1;
 
+#
+# Bug #27827: CHECK OPTION ignores ON conditions when updating
+#             a multi-table view with CHECK OPTION.
+#
+
+CREATE TABLE t1 (a1 INT, c INT DEFAULT 0);
+CREATE TABLE t2 (a2 INT);
+CREATE TABLE t3 (a3 INT);
+CREATE TABLE t4 (a4 INT);
+INSERT INTO t1 (a1) VALUES (1),(2);
+INSERT INTO t2 (a2) VALUES (1),(2);
+INSERT INTO t3 (a3) VALUES (1),(2);
+INSERT INTO t4 (a4) VALUES (1),(2);
+
+CREATE VIEW v1 AS
+  SELECT t1.a1, t1.c FROM t1 JOIN t2 ON t1.a1=t2.a2 AND t1.c < 3
+    WITH CHECK OPTION;
+SELECT * FROM v1;
+--error 1369
+UPDATE v1 SET c=3;
+PREPARE t FROM 'UPDATE v1 SET c=3';
+--error 1369
+EXECUTE t;
+--error 1369
+EXECUTE t;
+--error 1369
+INSERT INTO v1(a1, c) VALUES (3, 3);
+UPDATE v1 SET c=1 WHERE a1=1;
+SELECT * FROM v1;
+SELECT * FROM t1;
+
+CREATE VIEW v2 AS SELECT t1.a1, t1.c
+  FROM (t1 JOIN t2 ON t1.a1=t2.a2 AND t1.c < 3)
+  JOIN (t3 JOIN t4 ON t3.a3=t4.a4)
+    ON t2.a2=t3.a3 WITH CHECK OPTION;
+SELECT * FROM v2;
+--error 1369
+UPDATE v2 SET c=3;
+PREPARE t FROM 'UPDATE v2 SET c=3';
+--error 1369
+EXECUTE t;
+--error 1369
+EXECUTE t;
+--error 1369
+INSERT INTO v2(a1, c) VALUES (3, 3);
+UPDATE v2 SET c=2 WHERE a1=1;
+SELECT * FROM v2;
+SELECT * FROM t1;
+
+DROP VIEW v1,v2;
+DROP TABLE t1,t2,t3,t4;
+
 --echo End of 5.0 tests.

sql/table.cc

@@ -1985,6 +1985,47 @@ bool st_table_list::prep_where(THD *thd, Item **conds,
 }
 
 
+/*
+  Merge ON expressions for a view
+
+  SYNOPSIS
+    merge_on_conds()
+    thd             thread handle
+    table           table for the VIEW
+    is_cascaded     TRUE <=> merge ON expressions from underlying views
+
+  DESCRIPTION
+    This function returns the result of ANDing the ON expressions
+    of the given view and all underlying views. The ON expressions
+    of the underlying views are added only if is_cascaded is TRUE.
+
+  RETURN
+    Pointer to the built expression if there is any.
+    Otherwise and in the case of a failure NULL is returned.
+*/
+
+static Item *
+merge_on_conds(THD *thd, TABLE_LIST *table, bool is_cascaded)
+{
+  DBUG_ENTER("merge_on_conds");
+
+  Item *cond= NULL;
+  DBUG_PRINT("info", ("alias: %s", table->alias));
+  if (table->on_expr)
+    cond= table->on_expr->copy_andor_structure(thd);
+  if (!table->nested_join)
+    DBUG_RETURN(cond);
+  List_iterator<TABLE_LIST> li(table->nested_join->join_list);
+  while (TABLE_LIST *tbl= li++)
+  {
+    if (tbl->view && !is_cascaded)
+      continue;
+    cond= and_conds(cond, merge_on_conds(thd, tbl, is_cascaded));
+  }
+  DBUG_RETURN(cond);
+}
+
+
 /*
   Prepare check option expression of table
 
@@ -2001,8 +2042,8 @@ bool st_table_list::prep_where(THD *thd, Item **conds,
                       VIEW_CHECK_LOCAL option.
 
   NOTE
-    This method build check options for every call
-    (usual execution or every SP/PS call)
+    This method builds check option condition to use it later on
+    every call (usual execution or every SP/PS call).
     This method have to be called after WHERE preparation
     (st_table_list::prep_where)
 
@@ -2014,38 +2055,42 @@ bool st_table_list::prep_where(THD *thd, Item **conds,
 bool st_table_list::prep_check_option(THD *thd, uint8 check_opt_type)
 {
   DBUG_ENTER("st_table_list::prep_check_option");
+  bool is_cascaded= check_opt_type == VIEW_CHECK_CASCADED;
 
   for (TABLE_LIST *tbl= merge_underlying_list; tbl; tbl= tbl->next_local)
   {
     /* see comment of check_opt_type parameter */
-    if (tbl->view &&
-        tbl->prep_check_option(thd,
-                               ((check_opt_type == VIEW_CHECK_CASCADED) ?
+    if (tbl->view && tbl->prep_check_option(thd, (is_cascaded ?
                                                   VIEW_CHECK_CASCADED :
                                                   VIEW_CHECK_NONE)))
-    {
       DBUG_RETURN(TRUE);
   }
-  }
 
-  if (check_opt_type)
+  if (check_opt_type && !check_option_processed)
   {
-    Item *item= 0;
+    Query_arena *arena= thd->stmt_arena, backup;
+    arena= thd->activate_stmt_arena_if_needed(&backup);  // For easier test
+
     if (where)
     {
       DBUG_ASSERT(where->fixed);
-      item= where->copy_andor_structure(thd);
+      check_option= where->copy_andor_structure(thd);
     }
-    if (check_opt_type == VIEW_CHECK_CASCADED)
+    if (is_cascaded)
     {
       for (TABLE_LIST *tbl= merge_underlying_list; tbl; tbl= tbl->next_local)
       {
         if (tbl->check_option)
-          item= and_conds(item, tbl->check_option);
+          check_option= and_conds(check_option, tbl->check_option);
       }
     }
-    if (item)
-      thd->change_item_tree(&check_option, item);
+    check_option= and_conds(check_option,
+                            merge_on_conds(thd, this, is_cascaded));
+
+    if (arena)
+      thd->restore_active_arena(arena, &backup);
+    check_option_processed= TRUE;
+
   }
 
   if (check_option)
@@ -2150,7 +2195,7 @@ void st_table_list::cleanup_items()
   check CHECK OPTION condition
 
   SYNOPSIS
-    check_option()
+    st_table_list::view_check_option()
     ignore_failure ignore check option fail
 
   RETURN

sql/table.h

@@ -685,6 +685,8 @@ typedef struct st_table_list
   bool          compact_view_format;    /* Use compact format for SHOW CREATE VIEW */
   /* view where processed */
   bool          where_processed;
+  /* TRUE <=> VIEW CHECK OPTION expression has been processed */
+  bool          check_option_processed;
   /* FRMTYPE_ERROR if any type is acceptable */
   enum frm_type_enum required_type;
   char		timestamp_buffer[20];	/* buffer for timestamp (19+1) */