Fix for the following bugs:

  - BUG#15166: Wrong update permissions required to execute triggers
  - BUG#15196: Wrong select permission required to execute triggers

The idea of the fix is to check necessary privileges
in Item_trigger_field::fix_fields(), instead of having "special variables"
technique. To achieve this, we should pass to an Item_trigger_field instance
a flag, which will indicate the usage/access type of this trigger variable.


mysql-test/r/trigger-grant.result:
  Update the result file.
mysql-test/t/trigger-grant.test:
  Add test cases for BUG#15166 and BUG#15196
sql/item.cc:
  Item_trigger_field: check appropriate (SELECT/UPDATE) privilege in fix_fields().
sql/item.h:
  Add a flag to specify access type for trigger field.
sql/sql_trigger.cc:
  "Special variable" technique of checking privileges for NEW/OLD variables
  was replaced by checking table- and column-level privileges in
  Item_trigger_field::fix_fields().
sql/sql_trigger.h:
  "Special variable" technique of checking privileges for NEW/OLD variables
  was replaced by checking table- and column-level privileges in
  Item_trigger_field::fix_fields().
sql/sql_yacc.yy:
  Specify access type for trigger fields.

1 files changed, 184 insertions, 103 deletions

diff --git a/mysql-test/r/trigger-grant.result b/mysql-test/r/trigger-grant.result
index 858cab7a04a..87e5e11d779 100644
--- a/mysql-test/r/trigger-grant.result
+++ b/mysql-test/r/trigger-grant.result
@@ -65,109 +65,6 @@ user_str
 mysqltest_dfn@localhost
 mysqltest_dfn@localhost
 
----> connection: default
-use mysqltest_db1;
-REVOKE SELECT ON mysqltest_db1.t1 FROM mysqltest_dfn@localhost;
-
----> connection: wl2818_definer_con
-use mysqltest_db1;
-DROP TRIGGER trg1;
-SET @new_sum = 0;
-SET @old_sum = 0;
----> INSERT INTO statement; BEFORE timing
-CREATE TRIGGER trg1 BEFORE INSERT ON t1
-FOR EACH ROW
-SET @new_sum = @new_sum + NEW.num_value;
-INSERT INTO t1 VALUES(4);
-ERROR 42000: SELECT command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
----> INSERT INTO statement; AFTER timing
-DROP TRIGGER trg1;
-CREATE TRIGGER trg1 AFTER INSERT ON t1
-FOR EACH ROW
-SET @new_sum = @new_sum + NEW.num_value;
-INSERT INTO t1 VALUES(5);
-ERROR 42000: SELECT command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
----> UPDATE statement; BEFORE timing
-DROP TRIGGER trg1;
-CREATE TRIGGER trg1 BEFORE UPDATE ON t1
-FOR EACH ROW
-SET @old_sum = @old_sum + OLD.num_value;
-UPDATE t1 SET num_value = 10;
-ERROR 42000: SELECT command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
----> UPDATE statement; AFTER timing
-DROP TRIGGER trg1;
-CREATE TRIGGER trg1 AFTER UPDATE ON t1
-FOR EACH ROW
-SET @new_sum = @new_sum + NEW.num_value;
-UPDATE t1 SET num_value = 20;
-ERROR 42000: SELECT command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
----> DELETE statement; BEFORE timing
-DROP TRIGGER trg1;
-CREATE TRIGGER trg1 BEFORE DELETE ON t1
-FOR EACH ROW
-SET @old_sum = @old_sum + OLD.num_value;
-DELETE FROM t1;
-ERROR 42000: SELECT command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
----> DELETE statement; AFTER timing
-DROP TRIGGER trg1;
-CREATE TRIGGER trg1 AFTER DELETE ON t1
-FOR EACH ROW
-SET @old_sum = @old_sum + OLD.num_value;
-DELETE FROM t1;
-ERROR 42000: SELECT command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
-
----> connection: default
-use mysqltest_db1;
-GRANT SELECT ON mysqltest_db1.t1 TO mysqltest_dfn@localhost;
-REVOKE UPDATE ON mysqltest_db1.t1 FROM mysqltest_dfn@localhost;
-
----> connection: wl2818_definer_con
-use mysqltest_db1;
-DROP TRIGGER trg1;
-SET @new_sum = 0;
-SET @old_sum = 0;
----> INSERT INTO statement; BEFORE timing
-CREATE TRIGGER trg1 BEFORE INSERT ON t1
-FOR EACH ROW
-SET @new_sum = @new_sum + NEW.num_value;
-INSERT INTO t1 VALUES(4);
-ERROR 42000: UPDATE command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
----> INSERT INTO statement; AFTER timing
-DROP TRIGGER trg1;
-CREATE TRIGGER trg1 AFTER INSERT ON t1
-FOR EACH ROW
-SET @new_sum = @new_sum + NEW.num_value;
-INSERT INTO t1 VALUES(5);
-ERROR 42000: UPDATE command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
----> UPDATE statement; BEFORE timing
-DROP TRIGGER trg1;
-CREATE TRIGGER trg1 BEFORE UPDATE ON t1
-FOR EACH ROW
-SET @old_sum = @old_sum + OLD.num_value;
-UPDATE t1 SET num_value = 10;
-ERROR 42000: UPDATE command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
----> UPDATE statement; AFTER timing
-DROP TRIGGER trg1;
-CREATE TRIGGER trg1 AFTER UPDATE ON t1
-FOR EACH ROW
-SET @new_sum = @new_sum + NEW.num_value;
-UPDATE t1 SET num_value = 20;
-ERROR 42000: UPDATE command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
----> DELETE statement; BEFORE timing
-DROP TRIGGER trg1;
-CREATE TRIGGER trg1 BEFORE DELETE ON t1
-FOR EACH ROW
-SET @old_sum = @old_sum + OLD.num_value;
-DELETE FROM t1;
-ERROR 42000: UPDATE command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
----> DELETE statement; AFTER timing
-DROP TRIGGER trg1;
-CREATE TRIGGER trg1 AFTER DELETE ON t1
-FOR EACH ROW
-SET @old_sum = @old_sum + OLD.num_value;
-DELETE FROM t1;
-ERROR 42000: UPDATE command denied to user 'mysqltest_dfn'@'localhost' for table 't1'
-
 ---> connection: wl2818_definer_con
 use mysqltest_db1;
 DROP TRIGGER trg1;
@@ -229,3 +126,187 @@ DROP USER mysqltest_inv@localhost;
 DROP DATABASE mysqltest_db1;
 Warnings:
 Warning	1454	No definer attribute for trigger 'mysqltest_db1'.'trg1'. The trigger will be activated under the authorization of the invoker, which may have insufficient privileges. Please recreate the trigger.
+DELETE FROM mysql.user WHERE User LIKE 'mysqltest_%';
+DELETE FROM mysql.db WHERE User LIKE 'mysqltest_%';
+DELETE FROM mysql.tables_priv WHERE User LIKE 'mysqltest_%';
+DELETE FROM mysql.columns_priv WHERE User LIKE 'mysqltest_%';
+FLUSH PRIVILEGES;
+DROP DATABASE IF EXISTS mysqltest_db1;
+CREATE DATABASE mysqltest_db1;
+use mysqltest_db1;
+CREATE TABLE t1(col CHAR(20));
+CREATE TABLE t2(col CHAR(20));
+CREATE TABLE t3(col CHAR(20));
+CREATE TABLE t4(col CHAR(20));
+CREATE USER mysqltest_u1@localhost;
+REVOKE ALL PRIVILEGES, GRANT OPTION FROM mysqltest_u1@localhost;
+GRANT SUPER ON *.* TO mysqltest_u1@localhost;
+GRANT SELECT ON mysqltest_db1.t1 TO mysqltest_u1@localhost;
+SET @mysqltest_var = NULL;
+
+---> connection: default
+use mysqltest_db1;
+REVOKE SELECT ON mysqltest_db1.t1 FROM mysqltest_u1@localhost;
+GRANT DELETE ON mysqltest_db1.* TO mysqltest_u1@localhost;
+SHOW GRANTS FOR mysqltest_u1@localhost;
+Grants for mysqltest_u1@localhost
+GRANT SUPER ON *.* TO 'mysqltest_u1'@'localhost'
+GRANT DELETE ON `mysqltest_db1`.* TO 'mysqltest_u1'@'localhost'
+
+---> connection: bug15166_u1_con
+use mysqltest_db1;
+CREATE TRIGGER t1_trg_after_delete AFTER DELETE ON t1
+FOR EACH ROW
+SET @mysqltest_var = 'Hello, world!';
+
+---> connection: default
+use mysqltest_db1;
+GRANT UPDATE ON mysqltest_db1.t1 TO mysqltest_u1@localhost;
+GRANT UPDATE ON mysqltest_db1.t2 TO mysqltest_u1@localhost;
+GRANT UPDATE(col) ON mysqltest_db1.t3 TO mysqltest_u1@localhost;
+GRANT UPDATE(col) ON mysqltest_db1.t4 TO mysqltest_u1@localhost;
+
+---> connection: bug15166_u1_con
+use mysqltest_db1;
+CREATE TRIGGER t1_trg_err_1 BEFORE INSERT ON t1
+FOR EACH ROW
+SET @mysqltest_var = NEW.col;
+DROP TRIGGER t1_trg_err_1;
+CREATE TRIGGER t1_trg_err_2 BEFORE DELETE ON t1
+FOR EACH ROW
+SET @mysqltest_var = OLD.col;
+DROP TRIGGER t1_trg_err_2;
+CREATE TRIGGER t2_trg_before_insert BEFORE INSERT ON t2
+FOR EACH ROW
+SET NEW.col = 't2_trg_before_insert';
+CREATE TRIGGER t3_trg_err_1 BEFORE INSERT ON t3
+FOR EACH ROW
+SET @mysqltest_var = NEW.col;
+DROP TRIGGER t3_trg_err_1;
+CREATE TRIGGER t3_trg_err_2 BEFORE DELETE ON t3
+FOR EACH ROW
+SET @mysqltest_var = OLD.col;
+DROP TRIGGER t3_trg_err_2;
+CREATE TRIGGER t4_trg_before_insert BEFORE INSERT ON t4
+FOR EACH ROW
+SET NEW.col = 't4_trg_before_insert';
+
+---> connection: default
+use mysqltest_db1;
+REVOKE UPDATE ON mysqltest_db1.t1 FROM mysqltest_u1@localhost;
+REVOKE UPDATE ON mysqltest_db1.t2 FROM mysqltest_u1@localhost;
+GRANT SELECT ON mysqltest_db1.t1 TO mysqltest_u1@localhost;
+GRANT SELECT ON mysqltest_db1.t2 TO mysqltest_u1@localhost;
+REVOKE UPDATE(col) ON mysqltest_db1.t3 FROM mysqltest_u1@localhost;
+REVOKE UPDATE(col) ON mysqltest_db1.t4 FROM mysqltest_u1@localhost;
+GRANT SELECT(col) on mysqltest_db1.t3 TO mysqltest_u1@localhost;
+GRANT SELECT(col) on mysqltest_db1.t4 TO mysqltest_u1@localhost;
+
+---> connection: bug15166_u1_con
+use mysqltest_db1;
+CREATE TRIGGER t1_trg_after_insert AFTER INSERT ON t1
+FOR EACH ROW
+SET @mysqltest_var = NEW.col;
+CREATE TRIGGER t1_trg_after_update AFTER UPDATE ON t1
+FOR EACH ROW
+SET @mysqltest_var = OLD.col;
+CREATE TRIGGER t2_trg_err_1 BEFORE UPDATE ON t2
+FOR EACH ROW
+SET NEW.col = 't2_trg_err_1';
+DROP TRIGGER t2_trg_err_1;
+CREATE TRIGGER t2_trg_err_2 BEFORE UPDATE ON t2
+FOR EACH ROW
+SET NEW.col = CONCAT(OLD.col, '(updated)');
+DROP TRIGGER t2_trg_err_2;
+CREATE TRIGGER t3_trg_after_insert AFTER INSERT ON t3
+FOR EACH ROW
+SET @mysqltest_var = NEW.col;
+CREATE TRIGGER t3_trg_after_update AFTER UPDATE ON t3
+FOR EACH ROW
+SET @mysqltest_var = OLD.col;
+CREATE TRIGGER t4_trg_err_1 BEFORE UPDATE ON t4
+FOR EACH ROW
+SET NEW.col = 't4_trg_err_1';
+DROP TRIGGER t4_trg_err_1;
+CREATE TRIGGER t4_trg_err_2 BEFORE UPDATE ON t4
+FOR EACH ROW
+SET NEW.col = CONCAT(OLD.col, '(updated)');
+DROP TRIGGER t4_trg_err_2;
+
+---> connection: default
+use mysqltest_db1;
+REVOKE SELECT ON mysqltest_db1.t1 FROM mysqltest_u1@localhost;
+REVOKE SELECT ON mysqltest_db1.t2 FROM mysqltest_u1@localhost;
+GRANT UPDATE ON mysqltest_db1.t1 TO mysqltest_u1@localhost;
+GRANT UPDATE ON mysqltest_db1.t2 TO mysqltest_u1@localhost;
+REVOKE SELECT(col) ON mysqltest_db1.t3 FROM mysqltest_u1@localhost;
+REVOKE SELECT(col) ON mysqltest_db1.t4 FROM mysqltest_u1@localhost;
+GRANT UPDATE(col) ON mysqltest_db1.t3 TO mysqltest_u1@localhost;
+GRANT UPDATE(col) ON mysqltest_db1.t4 TO mysqltest_u1@localhost;
+INSERT INTO t1 VALUES('line1');
+ERROR 42000: SELECT command denied to user 'mysqltest_u1'@'localhost' for column 'col' in table 't1'
+SELECT * FROM t1;
+col
+line1
+SELECT @mysqltest_var;
+@mysqltest_var
+NULL
+INSERT INTO t2 VALUES('line2');
+SELECT * FROM t2;
+col
+t2_trg_before_insert
+INSERT INTO t3 VALUES('t3_line1');
+ERROR 42000: SELECT command denied to user 'mysqltest_u1'@'localhost' for column 'col' in table 't3'
+SELECT * FROM t3;
+col
+t3_line1
+SELECT @mysqltest_var;
+@mysqltest_var
+NULL
+INSERT INTO t4 VALUES('t4_line2');
+SELECT * FROM t4;
+col
+t4_trg_before_insert
+
+---> connection: default
+use mysqltest_db1;
+REVOKE UPDATE ON mysqltest_db1.t1 FROM mysqltest_u1@localhost;
+REVOKE UPDATE ON mysqltest_db1.t2 FROM mysqltest_u1@localhost;
+GRANT SELECT ON mysqltest_db1.t1 TO mysqltest_u1@localhost;
+GRANT SELECT ON mysqltest_db1.t2 TO mysqltest_u1@localhost;
+REVOKE UPDATE(col) ON mysqltest_db1.t3 FROM mysqltest_u1@localhost;
+REVOKE UPDATE(col) ON mysqltest_db1.t4 FROM mysqltest_u1@localhost;
+GRANT SELECT(col) ON mysqltest_db1.t3 TO mysqltest_u1@localhost;
+GRANT SELECT(col) ON mysqltest_db1.t4 TO mysqltest_u1@localhost;
+INSERT INTO t1 VALUES('line3');
+SELECT * FROM t1;
+col
+line1
+line3
+SELECT @mysqltest_var;
+@mysqltest_var
+line3
+INSERT INTO t2 VALUES('line4');
+ERROR 42000: UPDATE command denied to user 'mysqltest_u1'@'localhost' for column 'col' in table 't2'
+SELECT * FROM t2;
+col
+t2_trg_before_insert
+INSERT INTO t3 VALUES('t3_line2');
+SELECT * FROM t3;
+col
+t3_line1
+t3_line2
+SELECT @mysqltest_var;
+@mysqltest_var
+t3_line2
+INSERT INTO t4 VALUES('t4_line2');
+ERROR 42000: UPDATE command denied to user 'mysqltest_u1'@'localhost' for column 'col' in table 't4'
+SELECT * FROM t4;
+col
+t4_trg_before_insert
+DELETE FROM t1;
+SELECT @mysqltest_var;
+@mysqltest_var
+Hello, world!
+DROP USER mysqltest_u1@localhost;
+DROP DATABASE mysqltest_db1;