between 5.0 and 5.1.
The problem was that in the patch for Bug#11986 it was decided
to store original query in UTF8 encoding for the INFORMATION_SCHEMA.
This approach however turned out to be quite difficult to implement
properly. The main problem is to preserve the same IS-output after
dump/restore.
So, the fix is to rollback to the previous functionality, but also
to fix it to support multi-character-set-queries properly. The idea
is to generate INFORMATION_SCHEMA-query from the item-tree after
parsing view declaration. The IS-query should:
- be completely in UTF8;
- not contain character set introducers.
For more information, see WL4052.
suite)
Under some circumstances a combination of aggregate functions and
GROUP BY in a SELECT query over a VIEW could lead to incorrect
calculation of the result type of the aggregate function. This in
turn could result in incorrect results, or assertion failures on debug
builds.
Fixed by changing the logic in Item_sum_hybrid::fix_fields() so that
the argument's item is dereferenced before calling its type() method.
The problem is that CREATE VIEW statements inside prepared statements
weren't being expanded during the prepare phase, which leads to objects
not being allocated in the appropriate memory arenas.
The solution is to perform the validation of CREATE VIEW statements
during the prepare phase of a prepared statement. The validation
during the prepare phase assures that transformations of the parsed
tree will use the permanent arena of the prepared statement.
sending SIGHUP.
There were two problems:
- after some recent fix, the server started to crash after
receiving SIGHUP. That happened because LEX of new THD-object
was not properly initialized.
- user-specified log options were ignored when logs were reopened.
The fix is to 1) initialize LEX and 2) take user-specified options
into account.
There is no test case in this CS, because our test suite does not
support sending SIGHUP to the server.
a table name.
The problem was that fill_defined_view_parts() did not return
an error if a table is going to be altered. That happened if
the table was already in the table cache. In that case,
open_table() returned non-NULL value (valid TABLE-instance from
the cache).
The fix is to ensure that an error is thrown even if the table
is in the cache.
(This is a backport of the original patch for 5.1)
The problem is that when a stored procedure is being parsed for
the first execution, the body is copied to a temporary buffer
which is disregarded sometime after the statement is parsed.
And during this parsing phase, the rule for CREATE VIEW was
holding a reference to the string being parsed for use during
the execution of the CREATE VIEW statement, leading to invalid
memory access later.
The solution is to allocate and copy the SELECT of a CREATE
VIEW statement using the thread memory root, which is set to
the permanent arena of the stored procedure.
Executing a prepared statement associated with a materialized
cursor yields to the client a metadata packet with wrong table
and database names. The problem was occurring because the server
was sending the the name of the temporary table used by the cursor
instead of the table name of the original table. The same problem
occurs when selecting from views, in which case the table name was
being sent and not the name of the view.
The solution is to fill the list item from the temporary table but
preserving the table and database names of the original fields. This
is achieved by tweaking the Select_materialize to accept a pointer to
the Materialized_cursor class which contains the item list to be filled.
a table name.
The problem was that fill_defined_view_parts() did not return
an error if a table is going to be altered. That happened if
the table was already in the table cache. In that case,
open_table() returned non-NULL value (valid TABLE-instance from
the cache).
The fix is to ensure that an error is thrown even if the table
is in the cache.
The test case for the bug#31048 checks that there is no crash on stack
overrun. But due to different stack sizes on different platforms it failed
on some of them.
The new test case check that a query with at least 4 level subquery nesting
works without the stack overrun nesting and other levels of nesting doesn't
cause a crash.
floating point numbers
Some math functions did not check if the result is a valid number
(i.e. neither of +-inf or nan).
Fixed by validating the result where necessary and returning NULL in
case of invalid result.
