Bug#28846 Use of undocumented Prepared Statements crashes server

ALTER VIEW is currently not supported as a prepared statement
and should be disabled as such as they otherwise could cause server crashes.

ALTER VIEW is currently not supported when called from stored
procedures or functions for related reasons and should also be disabled.

This patch disables these DDL statements and adjusts the appropriate test
cases accordingly.

Additional tests has been added to reflect on the fact that we do support
CREATE/ALTER/DROP TABLE for Prepared Statements (PS), Stored Procedures (SP)
and PS within SP.


mysql-test/r/ps_1general.result:
  - Updated test to reflect on the new policy to disallow ALTER VIEW within SP.
mysql-test/r/sp-dynamic.result:
  - Added PS ALTER TABLE test from within SP-context to demonstrate that CREATE/ALTER/DROP
  TABLE statements is working.
  - Added PS CREATE/ALTER/DROP VIEW tests from within SP-context to show that
  ALTER VIEW is not supported, CREATE VIEW/DROP VIEW are supported.
mysql-test/r/sp-error.result:
  - Updated test to reflect on the new policy to disallow VIEW DDL within SP.
mysql-test/t/ps_1general.test:
  - Updated test to reflect on the new policy to disallow VIEW DDL within SP.
mysql-test/t/sp-dynamic.test:
  - Add PS ALTER TABLE test from within SP to demonstrate that CREATE/ALTER/DROP
  TABLE statements are supported.
mysql-test/t/sp-error.test:
  - Updated test to reflect on the new policy to disallow ALTER VIEW
  within SP-context.
  - Changed error code 1314 to the more abstract ER_SP_BADSTATEMENT.
sql/sql_class.h:
  - Added comment for clarity
sql/sql_parse.cc:
  - Added comment for clarity
sql/sql_prepare.cc:
  - Disallow ALTER VIEW as prepared statements until they are
    properly supported. Note that SQLCOM_CREATE_VIEW also handles ALTER VIEW
    statements.
sql/sql_view.cc:
  - converted to doxygen comments
  - Added comment for clarity
sql/sql_yacc.yy:
  - Disallow ALTER VIEW statements within a SP.
  If the parser is operating within the SP context, this is shown
  on the sp->sphead pointer. If this flag is set for view DDL operations
  we stop parsing with the error 'ER_SP_BAD_STATEMENT'.

1 files changed, 2 insertions, 2 deletions

diff --git a/mysql-test/r/sp-error.result b/mysql-test/r/sp-error.result
index 7a2f812cde4..bd0640b2b14 100644
--- a/mysql-test/r/sp-error.result
+++ b/mysql-test/r/sp-error.result
@@ -982,9 +982,9 @@ ERROR HY000: Explicit or implicit commit is not allowed in stored function or tr
 CREATE FUNCTION bug_13627_f() returns int BEGIN create view v1 as select 1; return 1; END |
 ERROR HY000: Explicit or implicit commit is not allowed in stored function or trigger.
 CREATE TRIGGER tr1 BEFORE INSERT ON t1 FOR EACH ROW BEGIN alter view v1 as select 1; END |
-ERROR HY000: Explicit or implicit commit is not allowed in stored function or trigger.
+ERROR 0A000: ALTER VIEW is not allowed in stored procedures
 CREATE FUNCTION bug_13627_f() returns int BEGIN alter view v1 as select 1; return 1; END |
-ERROR HY000: Explicit or implicit commit is not allowed in stored function or trigger.
+ERROR 0A000: ALTER VIEW is not allowed in stored procedures
 CREATE TRIGGER tr1 BEFORE INSERT ON t1 FOR EACH ROW BEGIN drop view v1; END |
 ERROR HY000: Explicit or implicit commit is not allowed in stored function or trigger.
 CREATE FUNCTION bug_13627_f() returns int BEGIN drop view v1; return 1; END |