Problem: GROUP BY on empty ucs2 strings crashed server.
Reason: sometimes mi_unique_hash() is executed with
ptr=null and length=0, which means "empty string".
The branch of code handling UCS2 character set
was not safe against ptr=null and fell into and
endless loop even if length=0 because of poiter
arithmetic overflow.
Fix: adding special check for length=0 to avoid pointer arithmetic
overflow.
to 0 causes wrong (large) length to be read
from the row in _mi_calc_blob_length() when
storing NULL values in (e.g) POINT columns.
This large length is then used to allocate
a block of memory that (on some OSes) causes
trouble.
Fixed by calling the base class's
Field_blob::reset() from Field_geom::reset()
that is called when storing a NULL value into
the column.
This may lead to buffer overflow.
The String::qs_append() function will append a string
without checking if there's enough space.
So qs_append() must be called beforehand to ensure
there's enough space in the buffer for the subsequent
qs_append() calls.
Fixed Item_case_expr::print() to make sure there's
enough space before appending data by adding a call to
String::reserve() to make sure qs_append() will have
enough space.
* Modified Federated memory allocation to use MEM_ROOT
* Modified sql_servers and federated to allocate share connection
parameters to use MEM_ROOT
* Modified Federated to allow tablename in addition to server name
* Implicit flushing of tables using altered/dropped server name
* Added tests to prove new functionality works
Contributors to this patch: Patrick Galbraith, Antony Curtis
"Concurrent ALTER/CREATE SERVER can lead to deadlock"
Deadlock caused by inconsistant use of mutexes in sql_server.cc
One mutex has been removed to resolve deadlock.
Many functions were made private which should not be exported.
Unused variables and function removed.
context was used as an argument of GROUP_CONCAT.
Ensured correct setting of the depended_from field in references
generated for set functions aggregated in outer selects.
A wrong value of this field resulted in wrong maps returned by
used_tables() for these references.
Made sure that a temporary table field is added for any set function
aggregated in outer context when creation of a temporary table is
needed to execute the inner subquery.
another user.
When the DEFINER clause isn't specified in the ALTER statement then it's loaded
from the view definition. If the definer differs from the current user then
the error is thrown because only a super-user can set other users as a definers.
Now if the DEFINER clause is omitted in the ALTER VIEW statement then the
definer from the original view is used without check.
