Hello
On Czech pg mailing list was reported issue about problems with
boolean based domains and XML functions.
There are maybe more issues, but probably there is little bit strange
and unexpected result
postgres=# CREATE DOMAIN booldomain as bool;
CREATE DOMAIN
-- fully expected behave
postgres=# select true, true::booldomain;
bool | booldomain
------+------------
t | t
(1 row)
postgres=# select true::text, true::booldomain::text;
text | text
------+------
true | true
(1 row)
-- unexpected behave
postgres=# select xmlforest(true as bool, true::booldomain as booldomain);
xmlforest
---------------------------------------------
<bool>true</bool><booldomain>t</booldomain>
(1 row)
Best regards
Pavel Stehule