The function generate_derived_keys_for_table should set the value of
the number of keys for the derived table to 0 before it starts
generating key definitions for the table. It's important as the
function can be called twice by the optimizer for a derived table
if the query contains a subquery to which the IN-EXIST transformation
is applicable.
Fixed a valgrind complain.
If the expression for a derived table contained a clause LIMIT 0
SELECT from such derived table incorrectly returned a non-empty set.
Fixed by ensuring JOIN::do_send_rows to be updated after the call
of st_select_lex_unit::set_limit that sets the value of
JOIN::unit->select_limit_cnt.
Due to this bug in the function generate_derived_keys_for_table some
key definitions to access materialized derived tables or materialized
views were constructed with invalid info for their key parts.
This could make the server crash when it optimized queries using
materialized derived tables or materialized views.
Changed the code that processing of multi-updates and multi-deletes
with multitable views at the prepare stage.
A proper solution would be: never to perform any transformations of views
before and at the prepare stage. Yet it would require re-engineering
of the code that checks privileges and updatability of views.
Ultimately this re-engineering has to be done to provide a clean solution
for INSERT/UPDATE/DELETE statements that use views.
Fixed a valgrind problem in the function TABLE::use_index.
The function generate_derived_keys did not take into account the fact
that the last element in the array of keyuses could be just a barrier
element. In some cases it could lead to a crash of the server.
Also fixed a couple of other bugs in generate_derived_keys: the inner
loop in the body of if this function did not change the cycle variables
properly.
Resolved all conflicts, bad merges and fixed a few minor bugs in the code.
Commented out the queries from multi_update, view, subselect_sj, func_str,
derived_view, view_grant that failed either with crashes in ps-protocol or
with wrong results.
The failures are clear indications of some bugs in the code and these bugs
are to be fixed.
