Resolve iconv //IGNORE//TRANSLIT Inconsistency Between Systems

Author: oleibman

src/PhpSpreadsheet/Shared/StringHelper.php

@@ -480,7 +480,6 @@ public static function convertEncoding(string $textValue, string $to, string $fr
             if (false !== $result) {
                 return $result;
             }
-            var_dump($textValue, $from, $to . self::$iconvOptions);
         }
 
         return (string) mb_convert_encoding($textValue, $to, $from);

tests/PhpSpreadsheetTests/Shared/StringHelperTest.php

@@ -140,12 +140,21 @@ public function testNoIconv(): void
         $to = 'UTF-8';
         self::assertSame($expected, StringHelper::convertEncoding($string, $to, $from));
         self::assertSame('EUR', StringHelper::convertEncoding('€', 'ISO-8859-1', 'UTF-8'), 'transliterated');
-        self::assertSame('', StringHelper::convertEncoding('ﾂ', 'ISO-8859-1', 'UTF-8'), 'no transliteration so ignored');
         self::assertSame($expected, StringHelperNoIconv::convertEncoding($string, $to, $from));
         self::assertSame('?', StringHelperNoIconv::convertEncoding('€', 'ISO-8859-1', 'UTF-8'), 'using MB so no transliteration - just return question mark');
         self::assertSame($expected, StringHelperNoIconv2::convertEncoding($string, $to, $from));
         self::assertSame('?', StringHelperNoIconv2::convertEncoding('€', 'ISO-8859-1', 'UTF-8'), 'using MB so no transliteration - just return question mark');
         self::assertSame($expected, StringHelperNoIconv3::convertEncoding($string, $to, $from));
         self::assertSame('?', StringHelperNoIconv3::convertEncoding('€', 'ISO-8859-1', 'UTF-8'), 'using MB so no transliteration - just return question mark');
+
+        $noTransliteration = 'ﾂ';
+        $ignoreResult = '?';
+        if (StringHelper::getIsIconvEnabled()) {
+        // There is inconsistency in how //IGNORE//TRANSLIT operates
+            $ignoreResult = iconv('UTF-8', 'ISO-8859-1//IGNORE//TRANSLIT', $noTransliteration);
+            self::assertContains($ignoreResult, ['', '?']);
+        }
+        $result = StringHelper::convertEncoding($noTransliteration, 'ISO-8859-1', 'UTF-8');
+        self::assertSame($ignoreResult, $result, 'no transliteration available');
     }
 }