Fix global ICU collations for ICU < 54

createdb() didn't check for collation attributes validity, which has
to be done explicitly on ICU < 54.  It also forgot to close the ICU collator
opened during the check which leaks some memory.

To fix both, add a new check_icu_locale() that does all the appropriate
verification and close the ICU collator.

initdb also had some partial check for ICU < 54.  To have consistent error
reporting across major ICU versions, and get rid of the need to include ucol.h,
remove the partial check there.  The backend will report an error if needed
during the post-boostrap iniitialization phase.

Author: Julien Rouhaud <julien.rouhaud@free.fr>
Discussion: https://www.postgresql.org/message-id/20220319041459.qqqiqh335sga5ezj@jrouhaud

Author: petere

src/backend/commands/dbcommands.c

@@ -458,23 +458,7 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	}
 
 	if (dblocprovider == COLLPROVIDER_ICU)
-	{
-#ifdef USE_ICU
-		UErrorCode  status;
-
-		status = U_ZERO_ERROR;
-		ucol_open(dbiculocale, &status);
-		if (U_FAILURE(status))
-			ereport(ERROR,
-					(errmsg("could not open collator for locale \"%s\": %s",
-							dbiculocale, u_errorName(status))));
-#else
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("ICU is not supported in this build"), \
-				 errhint("You need to rebuild PostgreSQL using %s.", "--with-icu")));
-#endif
-	}
+		check_icu_locale(dbiculocale);
 
 	/*
 	 * Check that the new encoding and locale settings match the source

src/backend/utils/adt/pg_locale.c

@@ -1985,6 +1985,34 @@ icu_set_collation_attributes(UCollator *collator, const char *loc)
 
 #endif							/* USE_ICU */
 
+/*
+ * Check if the given locale ID is valid, and ereport(ERROR) if it isn't.
+ */
+void
+check_icu_locale(const char *icu_locale)
+{
+#ifdef USE_ICU
+	UCollator  *collator;
+	UErrorCode  status;
+
+	status = U_ZERO_ERROR;
+	collator = ucol_open(icu_locale, &status);
+	if (U_FAILURE(status))
+		ereport(ERROR,
+				(errmsg("could not open collator for locale \"%s\": %s",
+						icu_locale, u_errorName(status))));
+
+	if (U_ICU_VERSION_MAJOR_NUM < 54)
+		icu_set_collation_attributes(collator, icu_locale);
+	ucol_close(collator);
+#else
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("ICU is not supported in this build"), \
+			 errhint("You need to rebuild PostgreSQL using %s.", "--with-icu")));
+#endif
+}
+
 /*
  * These functions convert from/to libc's wchar_t, *not* pg_wchar_t.
  * Therefore we keep them here rather than with the mbutils code.

src/bin/initdb/Makefile

@@ -40,7 +40,7 @@ OBJS = \
 all: initdb
 
 initdb: $(OBJS) | submake-libpq submake-libpgport submake-libpgfeutils
-	$(CC) $(CFLAGS) $(OBJS) $(LDFLAGS) $(LDFLAGS_EX) $(LIBS) $(ICU_LIBS) -o $@$(X)
+	$(CC) $(CFLAGS) $(OBJS) $(LDFLAGS) $(LDFLAGS_EX) $(LIBS) -o $@$(X)
 
 # We must pull in localtime.c from src/timezones
 localtime.c: % : $(top_srcdir)/src/timezone/%

src/bin/initdb/initdb.c

@@ -55,10 +55,6 @@
 #include <signal.h>
 #include <time.h>
 
-#ifdef USE_ICU
-#include <unicode/ucol.h>
-#endif
-
 #ifdef HAVE_SHM_OPEN
 #include "sys/mman.h"
 #endif
@@ -2205,22 +2201,10 @@ setlocales(void)
 		}
 
 		/*
-		 * Check ICU locale ID
+		 * In supported builds, the ICU locale ID will be checked by the
+		 * backend when performing the post-boostrap initialization.
 		 */
-#ifdef USE_ICU
-		{
-			UErrorCode	status;
-
-			status = U_ZERO_ERROR;
-			ucol_open(icu_locale, &status);
-			if (U_FAILURE(status))
-			{
-				pg_log_error("could not open collator for locale \"%s\": %s",
-							 icu_locale, u_errorName(status));
-				exit(1);
-			}
-		}
-#else
+#ifndef USE_ICU
 		pg_log_error("ICU is not supported in this build");
 		fprintf(stderr, _("You need to rebuild PostgreSQL using %s.\n"), "--with-icu");
 		exit(1);

src/bin/initdb/t/001_initdb.pl

@@ -105,7 +105,7 @@
 		'option --icu-locale');
 
 	command_fails_like(['initdb', '--no-sync', '--locale-provider=icu', '--icu-locale=@colNumeric=lower', "$tempdir/dataX"],
-		qr/initdb: error: could not open collator for locale/,
+		qr/FATAL:  could not open collator for locale/,
 		'fails for invalid ICU locale');
 }
 else

src/include/utils/pg_locale.h

@@ -116,6 +116,7 @@ extern char *get_collation_actual_version(char collprovider, const char *collcol
 extern int32_t icu_to_uchar(UChar **buff_uchar, const char *buff, size_t nbytes);
 extern int32_t icu_from_uchar(char **result, const UChar *buff_uchar, int32_t len_uchar);
 #endif
+extern void check_icu_locale(const char *icu_locale);
 
 /* These functions convert from/to libc's wchar_t, *not* pg_wchar_t */
 extern size_t wchar2char(char *to, const wchar_t *from, size_t tolen,

src/test/icu/t/010_database.pl

@@ -16,11 +16,11 @@
 $node1->start;
 
 $node1->safe_psql('postgres',
-	q{CREATE DATABASE dbicu LOCALE_PROVIDER icu LOCALE 'C' ICU_LOCALE 'en-u-kf-upper' ENCODING 'UTF8' TEMPLATE template0});
+	q{CREATE DATABASE dbicu LOCALE_PROVIDER icu LOCALE 'C' ICU_LOCALE 'en@colCaseFirst=upper' ENCODING 'UTF8' TEMPLATE template0});
 
 $node1->safe_psql('dbicu',
 q{
-CREATE COLLATION upperfirst (provider = icu, locale = 'en-u-kf-upper');
+CREATE COLLATION upperfirst (provider = icu, locale = 'en@colCaseFirst=upper');
 CREATE TABLE icu (def text, en text COLLATE "en-x-icu", upfirst text COLLATE upperfirst);
 INSERT INTO icu VALUES ('a', 'a', 'a'), ('b', 'b', 'b'), ('A', 'A', 'A'), ('B', 'B', 'B');
 });