RENAME TABLE against a table with DATA/INDEX DIRECTORY overwrites
the file to which the symlink points.
This is security issue, because it is possible to create a table with
some name in some non-system database and set DATA/INDEX DIRECTORY
to mysql system database. Renaming this table to one of mysql system
tables (e.g. user, host) would overwrite the system table.
Return an error when the file to which the symlink points exist.
(This is a copy of changeset 2007/11/06 18:09:33+04:00 svoj@mysql.com
and its merge changesets on the way from 4.0 up to 5.0)
were accidentally removed during a previous rototill of this
code. Fixes bug#27692.
While it can be argued we should strive to provide a 'secure by
default' installation, this happens to be the setup currently
documented in the manual as the default, so defer changes that
improve security out of the box to a co-ordinated effort later
on.
For now, make a note about the test databases and anonymous user
in mysql_install_db and recommend that mysql_secure_installation
be ran for users wishing to remove these defaults.
[..re-commit of previously lost change..]
"pthread_mutex_trylock" isn't implemented correctly for the Windows platform.
This temporary patch reverts the patch for bug#21074 for Windows until
pthread_mutex_trylock is properly implemented.
added get_field_default_value() function which obtains default value from the field
(used in store_create_info() & get_schema_column_record() functions)
The optimizer sets index traversal in reverse order only if there are
used key parts that are not compared to a constant.
However using the primary key as an ORDER BY suffix rendered the check
incomplete : going in reverse order must still be used even if
all the parts of the secondary key are compared to a constant.
Fixed by relaxing the check and set reverse traversal even when all
the secondary index keyparts are compared to a const.
Also account for the case when all the primary keys are compared to a
constant.
- The bug was caused by COUNT(DISTINCT ...) code using Unique object in
a way that assumed that BIT(N) column occupies a contiguous space in
temp_table->record[0] buffer.
- The fix is to make COUNT(DISTINCT ...) code instruct create_tmp_table to
create temporary table with column of type BIGINT, not BIT(N).
Declaring an all space column name in the SELECT FROM DUAL or in a view
leads to misleading warning message:
"Leading spaces are removed from name ' '".
The Item::set_name method has been modified to raise warnings like
"Name ' ' has become ''" in case of the truncation of an all
space identifier to an empty string identifier instead of the
"Leading spaces are removed from name ' '" warning message.
