"Unknown column" error when using FULL JOIN with qualified field names

Running a SELECT query with FULL JOIN fails when some of the field names are qualified with their table names. The same query with a LEFT JOIN executes fine.

Code to reproduce:

create table a(aa int);
create table b(bb int);
insert into a values (12);
insert into b values (12);

/* Returns one row. */
select a.aa from a left join b on aa = bb;

/* Fails with "Unknown column 'a.aa' in 'field list'" */
select a.aa from a full join b on aa = bb;

/* Returns one row. */
select aa from a left join b on a.aa = bb;

/* Fails with "Unknown column 'a.aa' in 'on clause'" */
select aa from a full join b on a.aa = bb;