SELECT getdatabaseencoding() <> 'UTF8' AS skip_test \gset
\if :skip_test
\quit
\endif
SELECT U&'\0061\0308bc' <> U&'\00E4bc' COLLATE "C" AS sanity_check;
 sanity_check 
--------------
 t
(1 row)

SELECT unicode_version() IS NOT NULL;
 ?column? 
----------
 t
(1 row)

SELECT unicode_assigned(U&'abc');
 unicode_assigned 
------------------
 t
(1 row)

SELECT unicode_assigned(U&'abc\+10FFFF');
 unicode_assigned 
------------------
 f
(1 row)

SELECT normalize('');
 normalize 
-----------
 
(1 row)

SELECT normalize(U&'\0061\0308\24D1c') = U&'\00E4\24D1c' COLLATE "C" AS test_default;
 test_default 
--------------
 t
(1 row)

SELECT normalize(U&'\0061\0308\24D1c', NFC) = U&'\00E4\24D1c' COLLATE "C" AS test_nfc;
 test_nfc 
----------
 t
(1 row)

SELECT normalize(U&'\00E4bc', NFC) = U&'\00E4bc' COLLATE "C" AS test_nfc_idem;
 test_nfc_idem 
---------------
 t
(1 row)

SELECT normalize(U&'\00E4\24D1c', NFD) = U&'\0061\0308\24D1c' COLLATE "C" AS test_nfd;
 test_nfd 
----------
 t
(1 row)

SELECT normalize(U&'\0061\0308\24D1c', NFKC) = U&'\00E4bc' COLLATE "C" AS test_nfkc;
 test_nfkc 
-----------
 t
(1 row)

SELECT normalize(U&'\00E4\24D1c', NFKD) = U&'\0061\0308bc' COLLATE "C" AS test_nfkd;
 test_nfkd 
-----------
 t
(1 row)

SELECT "normalize"('abc', 'def');  -- run-time error
ERROR:  invalid normalization form: def
SELECT U&'\00E4\24D1c' IS NORMALIZED AS test_default;
 test_default 
--------------
 t
(1 row)

SELECT U&'\00E4\24D1c' IS NFC NORMALIZED AS test_nfc;
 test_nfc 
----------
 t
(1 row)

SELECT num, val,
    val IS NFC NORMALIZED AS NFC,
    val IS NFD NORMALIZED AS NFD,
    val IS NFKC NORMALIZED AS NFKC,
    val IS NFKD NORMALIZED AS NFKD
FROM
  (VALUES (1, U&'\00E4bc'),
          (2, U&'\0061\0308bc'),
          (3, U&'\00E4\24D1c'),
          (4, U&'\0061\0308\24D1c'),
          (5, '')) vals (num, val)
ORDER BY num;
 num | val | nfc | nfd | nfkc | nfkd 
-----+-----+-----+-----+------+------
   1 | äbc | t   | f   | t    | f
   2 | äbc | f   | t   | f    | t
   3 | äⓑc | t   | f   | f    | f
   4 | äⓑc | f   | t   | f    | f
   5 |     | t   | t   | t    | t
(5 rows)

SELECT is_normalized('abc', 'def');  -- run-time error
ERROR:  invalid normalization form: def