Stdlib: Locale::getDisplayName()/getDisplayLanguage()/getDisplayRegion() ignore $displayLocale — always English (ext/intl/locale)

[PurHur]

Category

bug · php-src-strict · Locale display names

Problem

VmLocale::getDisplayName / getDisplayLanguage / getDisplayRegion explicitly unset($displayLocale) and return a fixed English approximation. Zend uses ICU uloc_getDisplayName (etc.) so Locale::getDisplayName('en_US', 'fr') is French. Keyword display APIs already call ICU; name/language/region/script/variant still stub English.

Repro	Zend 8.2+	VM (2026-07-24)
Locale::getDisplayName('en_US', 'fr')	anglais (États-Unis)	English (United States)
Locale::getDisplayLanguage('en_US', 'fr')	anglais	English
Locale::getDisplayRegion('en_US', 'fr')	États-Unis	United States

php-src reference

• php/php-src ext/intl/locale/locale_methods.c — uloc_getDisplayName / uloc_getDisplayLanguage / uloc_getDisplayCountry
• Prior stubs: Stdlib: Locale class — getDefault()/getDisplayName() ICU locale API missing (ext/intl/locale) #6696, Stdlib: Locale::getDisplayLanguage()/getDisplayRegion()/getKeywordValue() missing after #20738 (ext/intl/locale) #20755 (methods exist; display-locale still deferred — comment cites Stdlib: extension_loaded('intl') phantom true — partial grapheme builtins register unloaded ext (ext/standard/info.c) #11472)

PHP implementation target

• ext/intl/VmLocale.php — wire getDisplayName/getDisplayLanguage/getDisplayRegion/getDisplayScript/getDisplayVariant through ICU like getDisplayKeyword* (reuse ulocDisplay* FFI path)
• PHP-in-PHP; thin ICU ABI only if already used for keywords

Repro

./script/docker-exec.sh -- bash -lc 'cat >/tmp/locale_display_fr.php <<'"'"'PHP'"'"'
<?php
echo Locale::getDisplayName("en_US", "fr"), "\n";
echo Locale::getDisplayLanguage("en_US", "fr"), "\n";
echo Locale::getDisplayRegion("en_US", "fr"), "\n";
PHP
php /tmp/locale_display_fr.php
php bin/vm.php /tmp/locale_display_fr.php'

Done when

• $displayLocale changes output to match Zend/ICU for name/language/region (and script/variant if in scope)
• Default/null display locale still sensible vs Zend
• Compliance .phpt; php-src-strict