bug #26215: mysql command line client should not strip comments
from SQL statements
and
bug #11230: Keeping comments when storing stored procedures
With the introduction of multiline comments support in the command line
client (mysql) in MySQL 4.1, it became impossible to preserve
client-side comments within single SQL statements or stored routines.
This feature was useful for monitoring tools and maintenance.
The patch adds a new option to the command line client
('--enable-comments', '-c') which allows to preserve SQL comments and
send them to the server for single SQL statements, and to keep comments
in the code for stored procedures / functions / triggers.
The patch is a modification of the contributed patch from bug #11230
with the following changes:
- code style changes to conform to the coding guidelines
- changed is_prefix() to my_strnncoll() to detect the DELIMITER
command, since the first one is case-sensitive and not charset-aware
- renamed t/comments-51.* to t/mysql_comments.*
- removed tests for comments in triggers since 5.0 does not have SHOW
CREATE TRIGGER (those tests will be added back in 5.1).
The test cases are only for bug #11230. No automated test case for bug
#26215 is possible due to the test suite deficiencies (though the cases
from the bug report were tested manually).
error evaluating WHERE"
DELETE with a subquery in WHERE clause would sometimes ignore subquery
evaluation error and proceed with deletion.
The fix is to check for an error after evaluation of the WHERE clause
in DELETE.
Addressed review comments.
If a stored function that contains a drop temporary table statement
is invoked by a create temporary table of the same name may cause
a server crash. The problem is that when dropping a table no check
is done to ensure that table is not being used by some outer query
(or outer statement), potentially leaving the outer query with a
reference to a stale (freed) table.
The solution is when dropping a temporary table, always check if
the table is being used by some outer statement as a temporary
table can be dropped inside stored procedures.
The check is performed by looking at the TABLE::query_id value for
temporary tables. To simplify this check and to solve a bug related
to handling of temporary tables in prelocked mode, this patch changes
the way in which this member is used to track the fact that table is
used/unused. Now we ensure that TABLE::query_id is zero for unused
temporary tables (which means that all temporary tables which were
used by a statement should be marked as free for reuse after it's
execution has been completed).
"ALTER SERVER can cause server to crash"
While retrieving values, it would erronously set the socket value
to NULL and attempt to use it in strcmp().
Ensure it is correctly set to "" so that strcmp may not crash.
The mysql_change_user command fails to properly update the database pointer
when no database is selected, leading to "use after free" errors. The same
happens on the user privilege pointer in the thread security context.
The solution is to properly reset and update the database name. Also update
the user_priv pointer so that it doesn't point to freed memory.
The HAVING clause is subject to the same rules as the SELECT list
about using aggregated and non-aggregated columns.
But this was not enforced when processing implicit grouping from
using aggregate functions.
Fixed by performing the same checks for HAVING as for SELECT.
fulltext index
Having a table with broken multibyte characters may cause fulltext
parser dead-loop.
Since normally it is not possible to insert broken multibyte sequence
into a table, this problem may arise only if table is damaged.
Affected statements are:
- CHECK/REPAIR against damaged table with fulltext index;
- boolean mode phrase search against damaged table with or
without fulltext inex;
- boolean mode searches without index;
- nlq searches.
No test case for this fix. Affects 5.0 only.