v10-0004-CREATE-COLLATION-default-provider.patch

From ea72d9f8baae263af0f7ce1b80bf624e0496a571 Mon Sep 17 00:00:00 2001
From: Jeff Davis <jeff@j-davis.com>
Date: Wed, 24 May 2023 09:53:02 -0700
Subject: [PATCH v10 4/4] CREATE COLLATION default provider.

If the LC_COLLATE or LC_CTYPE are specified for a new collation, the
default provider is libc. Otherwise, the default provider is the same
as the provider for the database default collation.

Previously, the default provider was always libc.
---
 contrib/citext/expected/create_index_acl.out     |  2 +-
 contrib/citext/sql/create_index_acl.sql          |  2 +-
 doc/src/sgml/ref/create_collation.sgml           | 12 +++++++++---
 src/backend/commands/collationcmds.c             |  7 ++++++-
 src/test/regress/expected/collate.linux.utf8.out | 10 +++++-----
 src/test/regress/sql/collate.linux.utf8.sql      | 10 +++++-----
 6 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/contrib/citext/expected/create_index_acl.out b/contrib/citext/expected/create_index_acl.out
index 33be13a92d..765867d36d 100644
--- a/contrib/citext/expected/create_index_acl.out
+++ b/contrib/citext/expected/create_index_acl.out
@@ -43,7 +43,7 @@ REVOKE ALL ON FUNCTION s.index_row_if FROM PUBLIC;
 -- Even for an empty table, CREATE INDEX checks ii_Predicate permissions.
 GRANT EXECUTE ON FUNCTION s.index_row_if TO regress_minimal;
 -- Non-extension, non-function objects.
-CREATE COLLATION s.coll (LOCALE="C");
+CREATE COLLATION s.coll (PROVIDER=libc, LOCALE="C");
 CREATE TABLE s.x (y s.citext);
 ALTER TABLE s.x OWNER TO regress_minimal;
 -- Empty-table DefineIndex()
diff --git a/contrib/citext/sql/create_index_acl.sql b/contrib/citext/sql/create_index_acl.sql
index 10b5225569..e338ac8799 100644
--- a/contrib/citext/sql/create_index_acl.sql
+++ b/contrib/citext/sql/create_index_acl.sql
@@ -45,7 +45,7 @@ REVOKE ALL ON FUNCTION s.index_row_if FROM PUBLIC;
 -- Even for an empty table, CREATE INDEX checks ii_Predicate permissions.
 GRANT EXECUTE ON FUNCTION s.index_row_if TO regress_minimal;
 -- Non-extension, non-function objects.
-CREATE COLLATION s.coll (LOCALE="C");
+CREATE COLLATION s.coll (PROVIDER=libc, LOCALE="C");
 CREATE TABLE s.x (y s.citext);
 ALTER TABLE s.x OWNER TO regress_minimal;
 -- Empty-table DefineIndex()
diff --git a/doc/src/sgml/ref/create_collation.sgml b/doc/src/sgml/ref/create_collation.sgml
index 48b62f77cb..2b25eff44e 100644
--- a/doc/src/sgml/ref/create_collation.sgml
+++ b/doc/src/sgml/ref/create_collation.sgml
@@ -136,9 +136,15 @@ CREATE COLLATION [ IF NOT EXISTS ] <replaceable>name</replaceable> FROM <replace
        Specifies the provider to use for locale services associated with this
        collation.  Possible values are <literal>builtin</literal>,
        <literal>icu</literal><indexterm><primary>ICU</primary></indexterm> (if
-       the server was built with ICU support) or <literal>libc</literal>.
-       <literal>libc</literal> is the default.  See <xref
-       linkend="locale-providers"/> for details.
+       the server was built with ICU support) or <literal>libc</literal>. See
+       <xref linkend="locale-providers"/> for details.
+      </para>
+      <para>
+       If <replaceable>lc_colllate</replaceable> or
+       <replaceable>lc_ctype</replaceable> is specified, the default is
+       <literal>libc</literal>; otherwise, the default is the same as the
+       provider for the database default collation (see <xref
+       linkend="sql-createdatabase"/>).
       </para>
       <para>
        If the provider is <literal>icu</literal> and the locale is
diff --git a/src/backend/commands/collationcmds.c b/src/backend/commands/collationcmds.c
index 58316ec19e..f2264000cb 100644
--- a/src/backend/commands/collationcmds.c
+++ b/src/backend/commands/collationcmds.c
@@ -229,7 +229,12 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
 								collproviderstr)));
 		}
 		else
-			collprovider = COLLPROVIDER_LIBC;
+		{
+			if (lccollateEl || lcctypeEl)
+				collprovider = COLLPROVIDER_LIBC;
+			else
+				collprovider = default_locale.provider;
+		}
 
 		if (localeEl)
 		{
diff --git a/src/test/regress/expected/collate.linux.utf8.out b/src/test/regress/expected/collate.linux.utf8.out
index 01664f7c1b..588198d13e 100644
--- a/src/test/regress/expected/collate.linux.utf8.out
+++ b/src/test/regress/expected/collate.linux.utf8.out
@@ -1026,7 +1026,7 @@ CREATE SCHEMA test_schema;
 -- We need to do this this way to cope with varying names for encodings:
 do $$
 BEGIN
-  EXECUTE 'CREATE COLLATION test0 (locale = ' ||
+  EXECUTE 'CREATE COLLATION test0 (provider = libc, locale = ' ||
           quote_literal((SELECT datcollate FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
@@ -1034,7 +1034,7 @@ CREATE COLLATION test0 FROM "C"; -- fail, duplicate name
 ERROR:  collation "test0" already exists
 CREATE COLLATION IF NOT EXISTS test0 FROM "C"; -- ok, skipped
 NOTICE:  collation "test0" already exists, skipping
-CREATE COLLATION IF NOT EXISTS test0 (locale = 'foo'); -- ok, skipped
+CREATE COLLATION IF NOT EXISTS test0 (provider = libc, locale = 'foo'); -- ok, skipped
 NOTICE:  collation "test0" for encoding "UTF8" already exists, skipping
 do $$
 BEGIN
@@ -1046,7 +1046,7 @@ END
 $$;
 CREATE COLLATION test3 (lc_collate = 'en_US.utf8'); -- fail, need lc_ctype
 ERROR:  parameter "lc_ctype" must be specified
-CREATE COLLATION testx (locale = 'nonsense'); -- fail
+CREATE COLLATION testx (provider = libc, locale = 'nonsense'); -- fail
 ERROR:  could not create locale "nonsense": No such file or directory
 DETAIL:  The operating system could not find any locale data for the locale name "nonsense".
 CREATE COLLATION test4 FROM nonsense;
@@ -1166,8 +1166,8 @@ SELECT * FROM collate_test2 ORDER BY b COLLATE UCS_BASIC;
 
 -- nondeterministic collations
 -- (not supported with libc provider)
-CREATE COLLATION ctest_det (locale = 'en_US.utf8', deterministic = true);
-CREATE COLLATION ctest_nondet (locale = 'en_US.utf8', deterministic = false);
+CREATE COLLATION ctest_det (provider = libc, locale = 'en_US.utf8', deterministic = true);
+CREATE COLLATION ctest_nondet (provider = libc, locale = 'en_US.utf8', deterministic = false);
 ERROR:  nondeterministic collations not supported with this provider
 -- cleanup
 SET client_min_messages TO warning;
diff --git a/src/test/regress/sql/collate.linux.utf8.sql b/src/test/regress/sql/collate.linux.utf8.sql
index 132d13af0a..2d031293d1 100644
--- a/src/test/regress/sql/collate.linux.utf8.sql
+++ b/src/test/regress/sql/collate.linux.utf8.sql
@@ -358,13 +358,13 @@ CREATE SCHEMA test_schema;
 -- We need to do this this way to cope with varying names for encodings:
 do $$
 BEGIN
-  EXECUTE 'CREATE COLLATION test0 (locale = ' ||
+  EXECUTE 'CREATE COLLATION test0 (provider = libc, locale = ' ||
           quote_literal((SELECT datcollate FROM pg_database WHERE datname = current_database())) || ');';
 END
 $$;
 CREATE COLLATION test0 FROM "C"; -- fail, duplicate name
 CREATE COLLATION IF NOT EXISTS test0 FROM "C"; -- ok, skipped
-CREATE COLLATION IF NOT EXISTS test0 (locale = 'foo'); -- ok, skipped
+CREATE COLLATION IF NOT EXISTS test0 (provider = libc, locale = 'foo'); -- ok, skipped
 do $$
 BEGIN
   EXECUTE 'CREATE COLLATION test1 (lc_collate = ' ||
@@ -374,7 +374,7 @@ BEGIN
 END
 $$;
 CREATE COLLATION test3 (lc_collate = 'en_US.utf8'); -- fail, need lc_ctype
-CREATE COLLATION testx (locale = 'nonsense'); -- fail
+CREATE COLLATION testx (provider = libc, locale = 'nonsense'); -- fail
 
 CREATE COLLATION test4 FROM nonsense;
 CREATE COLLATION test5 FROM test0;
@@ -455,8 +455,8 @@ SELECT * FROM collate_test2 ORDER BY b COLLATE UCS_BASIC;
 -- nondeterministic collations
 -- (not supported with libc provider)
 
-CREATE COLLATION ctest_det (locale = 'en_US.utf8', deterministic = true);
-CREATE COLLATION ctest_nondet (locale = 'en_US.utf8', deterministic = false);
+CREATE COLLATION ctest_det (provider = libc, locale = 'en_US.utf8', deterministic = true);
+CREATE COLLATION ctest_nondet (provider = libc, locale = 'en_US.utf8', deterministic = false);
 
 
 -- cleanup
-- 
2.34.1