GH-18344 add Locale::addLikelySubtags/Locale::minimizeSubtags support.

NEWS

@@ -94,6 +94,8 @@ PHP                                                                        NEWS
     (David Carlier)
   . Added null bytes presence in locale inputs for Locale class. (David Carlier)
   . Added grapheme_levenshtein() function. (Yuya Hamada)
+  . Added Locale::addLikelySubtags/Locale::minimizeSubtags to handle
+    adding/removing likely subtags to a locale. (David Carlier)
 
 - MySQLi:
   . Fixed bugs GH-17900 and GH-8084 (calling mysqli::__construct twice).

UPGRADING

@@ -178,6 +178,8 @@ PHP 8.5 UPGRADE NOTES
     NumberFormatter::CURRENCY_PLURAL, NumberFormatter::CASH_CURRENCY,
     and NumberFormatter::CURRENCY_STANDARD for various currency-related
     number formats.
+  . Added Locale::addLikelySubtags and Locale::minimizeSubtags to
+    handle likely tags on a given locale.
 
 - XSL:
   . The $namespace argument of XSLTProcessor::getParameter(),

ext/intl/locale/locale.stub.php

@@ -138,4 +138,14 @@ public static function acceptFromHttp(string $header): string|false {}
      * @alias locale_is_right_to_left
      */
     public static function isRightToLeft(string $locale): bool {}
+
+    /**
+     * @alias locale_add_likely_subtags
+     */
+    public static function addLikelySubtags(string $locale): string|false {}
+
+    /**
+     * @alias locale_minimize_subtags
+     */
+    public static function minimizeSubtags(string $locale): string|false {}
 }

ext/intl/locale/locale_methods.c

@@ -1639,3 +1639,49 @@ PHP_FUNCTION(locale_is_right_to_left)
 
 	RETURN_BOOL(uloc_isRightToLeft(locale));
 }
+
+PHP_FUNCTION(locale_add_likely_subtags)
+{
+	char *locale, maximized_locale[ULOC_FULLNAME_CAPACITY];
+	UErrorCode status = 0;
+	size_t locale_len;
+
+	ZEND_PARSE_PARAMETERS_START(1, 1)
+		Z_PARAM_PATH(locale, locale_len)
+	ZEND_PARSE_PARAMETERS_END();
+
+	if (!locale_len) {
+		locale = (char *)intl_locale_get_default();
+	}
+
+	int32_t maximized_locale_len = uloc_addLikelySubtags(locale, maximized_locale, sizeof(maximized_locale), &status);
+	INTL_CHECK_STATUS(status, "locale_add_likely_subtags: invalid locale");
+	if (maximized_locale_len < 0) {
+		RETURN_FALSE;
+	}
+
+	RETURN_STRINGL(maximized_locale, maximized_locale_len);
+}
+
+PHP_FUNCTION(locale_minimize_subtags)
+{
+	char *locale, minimized_locale[ULOC_FULLNAME_CAPACITY];
+	UErrorCode status = 0;
+	size_t locale_len;
+
+	ZEND_PARSE_PARAMETERS_START(1, 1)
+		Z_PARAM_PATH(locale, locale_len)
+	ZEND_PARSE_PARAMETERS_END();
+
+	if (!locale_len) {
+		locale = (char *)intl_locale_get_default();
+	}
+
+	int32_t minimized_locale_len = uloc_minimizeSubtags(locale, minimized_locale, sizeof(minimized_locale), &status);
+	INTL_CHECK_STATUS(status, "locale_minimize_subtags: invalid locale");
+	if (minimized_locale_len < 0) {
+		RETURN_FALSE;
+	}
+
+	RETURN_STRINGL(minimized_locale, minimized_locale_len);
+}

ext/intl/php_intl.stub.php

@@ -505,6 +505,10 @@ function locale_accept_from_http(string $header): string|false {}
 
 function locale_is_right_to_left(string $locale): bool {}
 
+function locale_add_likely_subtags(string $locale): string|false {}
+
+function locale_minimize_subtags(string $locale): string|false {}
+
 /* msgformat */
 
 function msgfmt_create(string $locale, string $pattern): ?MessageFormatter {}

ext/intl/tests/locale_subtags.phpt

@@ -0,0 +1,35 @@
+--TEST--
+Locale::addLikelySubtags/Locale::minimizeSubtags usage
+--EXTENSIONS--
+intl
+--FILE--
+<?php
+$locale = "en";
+$max = Locale::addLikelySubtags($locale);
+$min = Locale::minimizeSubtags($max);
+var_dump($min === $locale);
+var_dump($max !== $locale && strlen($max) > strlen($locale));
+var_dump(Locale::addLikelySubtags($max) === $max);
+var_dump(Locale::minimizeSubtags($locale) === $locale);
+var_dump(Locale::addLikelySubtags("%%%invalid%%%locale%%%"));
+var_dump(intl_get_error_message());
+var_dump(Locale::minimizeSubtags("%%%Invalid%%%maximized%%%locale%%%"));
+var_dump(intl_get_error_message());
+var_dump(Locale::addLikelySubTags(str_repeat($locale, 1024)));
+var_dump(intl_get_error_message());
+var_dump(Locale::minimizeSubTags(str_repeat($max, 1024)));
+var_dump(intl_get_error_message());
+?>
+--EXPECTF--
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(false)
+string(67) "locale_add_likely_subtags: invalid locale: U_ILLEGAL_ARGUMENT_ERROR"
+bool(false)
+string(65) "locale_minimize_subtags: invalid locale: U_ILLEGAL_ARGUMENT_ERROR"
+bool(false)
+string(%d) "locale_add_likely_subtags: invalid locale: %s"
+bool(false)
+string(%d) "locale_minimize_subtags: invalid locale: %s"