-- Tests for nlssort
-- Skip this test unless it's a Linux/glibc system with the "en_US.utf8" locale installed.
SELECT getdatabaseencoding() <> 'UTF8' OR
       NOT EXISTS (SELECT 1 FROM pg_collation WHERE collname = 'en_US' AND collencoding = pg_char_to_encoding('UTF8')) OR
       version() !~ 'linux-gnu'
       AS skip_test \gset
\if :skip_test
\quit
\endif
\set ECHO none
  name  
--------
 brown
 Purple
 red
 yellow
(4 rows)

  name  
--------
 Purple
 brown
 red
 yellow
(4 rows)

 set_nls_sort 
--------------
 
(1 row)

ERROR:  failed to set the requested LC_COLLATE value [invalid]
CONTEXT:  SQL function "nlssort" statement 1
 set_nls_sort 
--------------
 
(1 row)

  name  
--------
 Purple
 brown
 red
 yellow
(4 rows)

 set_nls_sort 
--------------
 
(1 row)

  name  
--------
 brown
 Purple
 red
 yellow
(4 rows)

  name  
--------
 brown
 Purple
 red
 yellow
 
(5 rows)