OC_Util: Add fallbacks to check if current locale is UTF8

Using escapeshellcmd to get current locale causes error
if the function is disabled.

Add fallbacks to prevent the error.

Signed-off-by: Naoto Kobayashi <naoto.kobayashi4c@gmail.com>

lib/private/legacy/OC_Util.php

@@ -1238,6 +1238,21 @@ class OC_Util {
 		return $content !== $testContent && $fallbackContent !== $testContent;
 	}
 
+	/**
+	 * Check if current locale is non-UTF8
+	 *
+	 * @return bool
+	 */
+	private static function isNonUTF8Locale() {
+		if (function_exists("escapeshellcmd")) {
+			return ('' === escapeshellcmd('§'));
+		} else if (function_exists("escapeshellarg")) {
+			return ('\'\'' === escapeshellarg('§'));
+		} else {
+			return (0 === preg_match('/utf-?8/i', setlocale(LC_CTYPE, 0)));
+		}
+	}
+
 	/**
 	 * Check if the setlocal call does not work. This can happen if the right
 	 * local packages are not available on the server.
@@ -1245,13 +1260,13 @@ class OC_Util {
 	 * @return bool
 	 */
 	public static function isSetLocaleWorking() {
-		if ('' === escapeshellcmd('§')) {
+		if (self::isNonUTF8Locale()) {
 			// Borrowed from \Patchwork\Utf8\Bootup::initLocale
 			setlocale(LC_ALL, 'C.UTF-8', 'C');
 			setlocale(LC_CTYPE, 'en_US.UTF-8', 'fr_FR.UTF-8', 'es_ES.UTF-8', 'de_DE.UTF-8', 'ru_RU.UTF-8', 'pt_BR.UTF-8', 'it_IT.UTF-8', 'ja_JP.UTF-8', 'zh_CN.UTF-8', '0');
 
 			// Check again
-			if ('' === escapeshellcmd('§')) {
+			if (self::isNonUTF8Locale()) {
 				return false;
 			}
 		}

tests/lib/UtilTest.php

@@ -74,13 +74,15 @@ class UtilTest extends \Test\TestCase {
 		$this->assertEquals("/%C2%A7%23%40test%25%26%5E%C3%A4/-child", $result);
 	}
 
-	public function testIsSetLocaleWorking() {
-		// OC_Util::isSetLocaleWorking() assumes escapeshellcmd('§') returns '' with non-UTF-8 locale.
+	public function testIsNonUTF8Locale() {
+		// OC_Util::isNonUTF8Locale() assumes escapeshellcmd('§') returns '' with non-UTF-8 locale.
 		$locale = setlocale(LC_CTYPE, 0);
 		setlocale(LC_CTYPE, 'C');
 		$this->assertEquals('', escapeshellcmd('§'));
+		$this->assertEquals('\'\'', escapeshellarg('§'));
 		setlocale(LC_CTYPE, 'C.UTF-8');
 		$this->assertEquals('§', escapeshellcmd('§'));
+		$this->assertEquals('\'§\'', escapeshellarg('§'));
 		setlocale(LC_CTYPE, $locale);
 	}