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FIxed bug #14927.

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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.
This commit is contained in:
igor@rurik.mysql.com
2006-01-31 21:48:32 -08:00
parent 7e5108392d
commit d6370b48a7
6 changed files with 57 additions and 11 deletions
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10
sql/sql_prepare.cc
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@ -1665,10 +1665,11 @@ int mysql_stmt_prepare(THD *thd, char *packet, uint packet_length,
for (; sl; sl= sl->next_select_in_list())
{
/*
Save WHERE clause pointers, because they may be changed
Save WHERE, HAVING clause pointers, because they may be changed
during query optimisation.
*/
sl->prep_where= sl->where;
sl->prep_having= sl->having;
/*
Switch off a temporary flag that prevents evaluation of
subqueries in statement prepare.
@ -1694,13 +1695,18 @@ static void reset_stmt_for_execute(Prepared_statement *stmt)
/* remove option which was put by mysql_explain_union() */
sl->options&= ~SELECT_DESCRIBE;
/*
Copy WHERE clause pointers to avoid damaging they by optimisation
Copy WHERE, HAVING clause pointers to avoid damaging they by optimisation
*/
if (sl->prep_where)
{
sl->where= sl->prep_where->copy_andor_structure(thd);
sl->where->cleanup();
}
if (sl->prep_having)
{
sl->having= sl->prep_having->copy_andor_structure(thd);
sl->having->cleanup();
}
DBUG_ASSERT(sl->join == 0);
ORDER *order;
/* Fix GROUP list */