Fix for BUG#9412: Triggers: should have trigger privilege.

Implement table-level TRIGGER privilege to control access to triggers.
Before this path global SUPER privilege was used for this purpose, that
was the big security problem.

In details, before this patch SUPER privilege was required:
  - for the user at CREATE TRIGGER time to create a new trigger;
  - for the user at DROP TRIGGER time to drop the existing trigger;
  - for the definer at trigger activation time to execute the trigger (if the
    definer loses SUPER privilege, all its triggers become unavailable);

This patch changes the behaviour in the following way:
  - TRIGGER privilege on the subject table for trigger is required:
    - for the user at CREATE TRIGGER time to create a new trigger;
    - for the user at DROP TRIGGER time to drop the existing trigger;
    - for the definer at trigger activation time to execute the trigger
      (if the definer loses TRIGGER privilege on the subject table, all its
      triggers on this table become unavailable).
  - SUPER privilege is still required:
    - for the user at CREATE TRIGGER time to explicitly set the trigger
      definer to the user other than CURRENT_USER().

When the server works with database of the previous version (w/o TRIGGER
privilege), or if the database is being upgraded from the previous versions,
TRIGGER privilege is granted to whose users, who have CREATE privilege.


mysql-test/r/grant.result:
  Updated the result file after adding TRIGGER privilege.
mysql-test/r/information_schema.result:
  Updated the result file after adding TRIGGER privilege.
mysql-test/r/lowercase_table_grant.result:
  Updated the result file after adding TRIGGER privilege.
mysql-test/r/ps.result:
  Updated the result file after adding TRIGGER privilege.
mysql-test/r/sp.result:
  Updated the result file after adding TRIGGER privilege.
mysql-test/r/trigger-compat.result:
  Updated the result file after adding TRIGGER privilege.
mysql-test/r/trigger-grant.result:
  Updated the result file after adding TRIGGER privilege.
mysql-test/t/trigger-compat.test:
  Grant table-level TRIGGER privilege instead of global SUPER one.
mysql-test/t/trigger-grant.test:
  1. Grant table-level TRIGGER privilege instead of global SUPER one.
  2. Updated the test case to check that SUPER is required to specify
  the user other than the current as a definer.
scripts/mysql_create_system_tables.sh:
  Added TRIGGER privilege.
scripts/mysql_fix_privilege_tables.sql:
  Added TRIGGER privilege.
sql/sql_acl.cc:
  Added TRIGGER privilege.
sql/sql_acl.h:
  Added TRIGGER privilege.
sql/sql_show.cc:
  Added TRIGGER privilege.
sql/sql_trigger.cc:
  Check TRIGGER privilege instead of SUPER.
sql/sql_yacc.yy:
  Added TRIGGER privilege.

1 files changed, 2 insertions, 0 deletions

diff --git a/mysql-test/r/sp.result b/mysql-test/r/sp.result
index acd32564f51..b9af0a8b075 100644
--- a/mysql-test/r/sp.result
+++ b/mysql-test/r/sp.result
@@ -2197,6 +2197,7 @@ Show databases	Server Admin	To see all databases with SHOW DATABASES
 Show view	Tables	To see views with SHOW CREATE VIEW
 Shutdown	Server Admin	To shut down the server
 Super	Server Admin	To use KILL thread, SET GLOBAL, CHANGE MASTER, etc.
+Trigger	Tables	To use triggers
 Update	Tables	To update existing rows
 Usage	Server Admin	No privileges - allow connect only
 Variable_name	Value
@@ -2250,6 +2251,7 @@ Show databases	Server Admin	To see all databases with SHOW DATABASES
 Show view	Tables	To see views with SHOW CREATE VIEW
 Shutdown	Server Admin	To shut down the server
 Super	Server Admin	To use KILL thread, SET GLOBAL, CHANGE MASTER, etc.
+Trigger	Tables	To use triggers
 Update	Tables	To update existing rows
 Usage	Server Admin	No privileges - allow connect only
 Variable_name	Value