Commit 21e79331 authored by Sergei Petrunia's avatar Sergei Petrunia

MDEV-22779: Crash: Prepared Statement with a '?' parameter inside a re-used CTE

When a prepared statement parameter '?' is used in a CTE that is used
multiple times, the following happens:
- The CTE definition is re-parsed multiple times.
- There are multiple Item_param objects referring to the same "?" in
the original query.
- Prepared_statement::param has a pointer to the first of them, the
  others are "clones".
- When prepared statement parameter gets the value, it should be passed
  over to clones with param->sync_clones() call.

This call is made in insert_params(), etc. It was not made in
insert_params_with_log().

This would cause Item_param to not have any value which would confuse
the query optimizer.

Added the missing call.
parent 2cd6afb0
......@@ -903,6 +903,8 @@ static bool insert_params_with_log(Prepared_statement *stmt, uchar *null_array,
if (param->convert_str_value(thd))
DBUG_RETURN(1); /* out of memory */
param->sync_clones();
}
if (acc.finalize())
DBUG_RETURN(1);
......
......@@ -5997,6 +5997,7 @@ static void optimize_keyuse(JOIN *join, DYNAMIC_ARRAY *keyuse_array)
uint n_tables= my_count_bits(map);
if (n_tables == 1) // Only one table
{
DBUG_ASSERT(!(map & PSEUDO_TABLE_BITS)); // Must be a real table
Table_map_iterator it(map);
int tablenr= it.next_bit();
DBUG_ASSERT(tablenr != Table_map_iterator::BITMAP_END);
......
......@@ -19843,6 +19843,57 @@ static void test_bulk_replace()
}
#endif
static void test_ps_params_in_ctes()
{
int rc;
const char *query;
MYSQL_BIND ps_params[1];
int int_data[1];
MYSQL_STMT *stmt;
rc= mysql_query(mysql, "create table t1(a int, b int, key(a))");
myquery(rc);
rc= mysql_query(mysql, "insert into t1 (a) values "
"(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)");
myquery(rc);
query=
"explain "
"with T as "
"( "
" select * from t1 where t1.a=? limit 2 "
") "
"select * from T as TA, T as TB;";
stmt= mysql_stmt_init(mysql);
check_stmt(stmt);
rc= mysql_stmt_prepare(stmt, query, (uint) strlen(query));
check_execute(stmt, rc);
int_data[0]=2;
ps_params[0].buffer_type= MYSQL_TYPE_LONG;
ps_params[0].buffer= (char *) &int_data[0];
ps_params[0].length= 0;
ps_params[0].is_null= 0;
rc= mysql_stmt_bind_param(stmt, ps_params);
check_execute(stmt, rc);
rc= mysql_stmt_execute(stmt);
check_execute(stmt, rc);
rc= mysql_stmt_store_result(stmt);
check_execute(stmt, rc);
rc= mysql_query(mysql, "drop table t1");
myquery(rc);
}
static struct my_tests_st my_tests[]= {
{ "disable_query_logs", disable_query_logs },
{ "test_view_sp_list_fields", test_view_sp_list_fields },
......@@ -20127,6 +20178,7 @@ static struct my_tests_st my_tests[]= {
{ "test_bulk_delete", test_bulk_delete },
{ "test_bulk_replace", test_bulk_replace },
#endif
{ "test_ps_params_in_ctes", test_ps_params_in_ctes },
{ 0, 0 }
};
......
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