TYPO3 Core

mm-joining a table on itself via pi_exec_query //-> pi_list_query results an incorrect mysql query.
(But only if you join it on ITSELF!)

This is what pi_list_query does (the crucial part is right in the first line):

if (is_array($mm_cat))    {
        $query='FROM '.$table.','.$mm_cat['table'].','.$mm_cat['mmtable'].chr(10).
                        ' WHERE '.$table.'.uid='.$mm_cat['mmtable'].'.uid_local AND '.$mm_cat ...

This makes a query like "FROM fe_users,fe_users,fe_users_tx_extension_mm ...

To get it right you need a uniquely specified table which creates something like

FROM fe_users,fe_users_tx_extension_mm,fe_users AS fe_users_join449d75344c5d1 ...

(have a look in the db class, there mm joins are prefixed correctly).

I hotfixed pi_list_query for myself with

if (is_array($mm_cat))    {

if($table == $mm_cat['table']) 
{
                    $mm_cat['table_2']=$mm_cat['table'];
                    $mm_cat['unique_table']=$mm_cat['table'].$mm_cat['unique_identifier'];
                    $mm_cat['table']=$mm_cat['unique_table'];
                    $as = ' AS '.$mm_cat['unique_table'];
                }
                else
{
                    $as='';
                    $mm_cat['table_2']=$mm_cat['table'];
                }
$query=    'FROM '.$table.','.$mm_cat['mmtable'].','.$mm_cat['table_2'].$as.' '.chr(10).
                        'WHERE '.$table.'.uid='.$mm_cat['mmtable'].'.uid_local AND '.$mm_cat['table'].'.uid='.$mm_cat['mmtable'].'.uid_foreign '.chr(10) ...

But observe that the unique identifier MUST NOT be defined in pi_list_query itself because it would break standard extension behavior of pi_exec_query in freshly created kickstarter extensions. To make it work the unique identifier would have to be defined previously. $this->internal array could be a good place for that .
(issue imported from #M3737)