Reduce icu_validation_level default to WARNING.

Discussion: https://postgr.es/m/daa9f060aa2349ebc84444515efece49e7b32c5d.camel@j-davis.com

doc/src/sgml/config.sgml

@@ -9841,7 +9841,7 @@ SET XML OPTION { DOCUMENT | CONTENT };
        <para>
         If set to <literal>DISABLED</literal>, does not report validation
         problems at all. Otherwise reports problems at the given message
-        level. The default is <literal>ERROR</literal>.
+        level. The default is <literal>WARNING</literal>.
        </para>
       </listitem>
      </varlistentry>

src/backend/utils/adt/pg_locale.c

@@ -96,7 +96,7 @@ char	   *locale_monetary;
 char	   *locale_numeric;
 char	   *locale_time;
 
-int			icu_validation_level = ERROR;
+int			icu_validation_level = WARNING;
 
 /*
  * lc_time localization cache.

src/backend/utils/misc/guc_tables.c

@@ -4689,7 +4689,7 @@ struct config_enum ConfigureNamesEnum[] =
 		 NULL
 		},
 		&icu_validation_level,
-		ERROR, icu_validation_level_options,
+		WARNING, icu_validation_level_options,
 		NULL, NULL, NULL
 	},
 

src/backend/utils/misc/postgresql.conf.sample

@@ -734,7 +734,7 @@
 #lc_numeric = 'C'			# locale for number formatting
 #lc_time = 'C'				# locale for time formatting
 
-#icu_validation_level = ERROR		# report ICU locale validation
+#icu_validation_level = WARNING		# report ICU locale validation
 					# errors at the given level
 
 # default configuration for text search

src/test/regress/expected/collate.icu.utf8.out

@@ -1037,18 +1037,18 @@ $$;
 RESET client_min_messages;
 CREATE COLLATION test3 (provider = icu, lc_collate = 'en_US.utf8'); -- fail, needs "locale"
 ERROR:  parameter "locale" must be specified
+SET icu_validation_level = ERROR;
 CREATE COLLATION testx (provider = icu, locale = 'nonsense-nowhere'); -- fails
 ERROR:  ICU locale "nonsense-nowhere" has unknown language "nonsense"
 HINT:  To disable ICU locale validation, set parameter icu_validation_level to DISABLED.
 CREATE COLLATION testx (provider = icu, locale = '@colStrength=primary;nonsense=yes'); -- fails
 ERROR:  could not convert locale name "@colStrength=primary;nonsense=yes" to language tag: U_ILLEGAL_ARGUMENT_ERROR
-SET icu_validation_level = WARNING;
+RESET icu_validation_level;
 CREATE COLLATION testx (provider = icu, locale = '@colStrength=primary;nonsense=yes'); DROP COLLATION testx;
 WARNING:  could not convert locale name "@colStrength=primary;nonsense=yes" to language tag: U_ILLEGAL_ARGUMENT_ERROR
 CREATE COLLATION testx (provider = icu, locale = 'nonsense-nowhere'); DROP COLLATION testx;
 WARNING:  ICU locale "nonsense-nowhere" has unknown language "nonsense"
 HINT:  To disable ICU locale validation, set parameter icu_validation_level to DISABLED.
-RESET icu_validation_level;
 CREATE COLLATION test4 FROM nonsense;
 ERROR:  collation "nonsense" for encoding "UTF8" does not exist
 CREATE COLLATION test5 FROM test0;

src/test/regress/sql/collate.icu.utf8.sql

@@ -376,12 +376,12 @@ $$;
 RESET client_min_messages;
 
 CREATE COLLATION test3 (provider = icu, lc_collate = 'en_US.utf8'); -- fail, needs "locale"
+SET icu_validation_level = ERROR;
 CREATE COLLATION testx (provider = icu, locale = 'nonsense-nowhere'); -- fails
 CREATE COLLATION testx (provider = icu, locale = '@colStrength=primary;nonsense=yes'); -- fails
-SET icu_validation_level = WARNING;
+RESET icu_validation_level;
 CREATE COLLATION testx (provider = icu, locale = '@colStrength=primary;nonsense=yes'); DROP COLLATION testx;
 CREATE COLLATION testx (provider = icu, locale = 'nonsense-nowhere'); DROP COLLATION testx;
-RESET icu_validation_level;
 
 CREATE COLLATION test4 FROM nonsense;
 CREATE COLLATION test5 FROM test0;