When an ambiguous field name is used in a group by clause a warning is issued
in the find_order_in_list function by a call to push_warning_printf.
An expression that was not always valid was passed to this call as the field
name parameter.
There are (at least) two implementations of the checksum
computation. One is in MyISAM for the quick checksum. It
is executed on every row change. The other is in the
SQL layer for the extended checksum. It retrieves all rows
of a table via the respective storage engine.
In former MySQL versions varchars were stored with their
maximum length, but now with their real length similar to
blobs.
This change had been forgotten to take care of in the
extended checksum calculation. Hence too much data was
checksumed. In MyISAM this change had been taken care of
already. Only the real data is included in the checksum.
I changed mysql_checksum_table() so that it uses the
length information of true varchar fields instead
of the field length like in former varchar
implementations.
A query with a group by and having clauses could return a wrong
result set if the having condition contained a constant conjunct
evaluated to FALSE.
It happened because the pushdown condition for table with
grouping columns lost its constant conjuncts.
Pushdown conditions are always built by the function make_cond_for_table
that ignores constant conjuncts. This is apparently not correct when
constant false conjuncts are present.
- Change "mysql_create_db" to not call "send_ok" if in silent mode i.e. called from "load_master_data"
- Change mysqltest to detect when there aren't as many warnings available as was reported.
The problem has manifested itself in the cases when we have a nested outer join
for which it can be inferred that one of the inner tables is a single row table.
After trying multiple inheritance (to messy and hard make it work) and
sublassing jump_if_not (worked, but ugly), decided to on this solution
instead:
Inserting an abstract sp_instr_opt_meta class as parent for all instructions
with destinations makes it possible to handle a continuation pointer for
sp_instr_set_case_expr too.
Note: No special test case; the fix is captured by the changed behaviour of
bug14643_2, and bug14498_4 (formerly disabled), in sp.test.
Second version.
The problem was that the optimizer didn't work correctly with forwards jumps
to "no-op" hpop and cpop instructions.
Don't generate "no-op" instructions (hpop 0 and cpop 0), it isn't actually
necessary.
- BUG#15166: Wrong update permissions required to execute triggers
- BUG#15196: Wrong select permission required to execute triggers
The idea of the fix is to check necessary privileges
in Item_trigger_field::fix_fields(), instead of having "special variables"
technique. To achieve this, we should pass to an Item_trigger_field instance
a flag, which will indicate the usage/access type of this trigger variable.
