Remove Unwanted Tests

src/PhpSpreadsheet/Calculation/MathTrig/Arabic.php

@@ -74,11 +74,14 @@ class Arabic
         // Convert the roman numeral to an arabic number
         $negativeNumber = $roman[0] === '-';
         if ($negativeNumber) {
-            $roman = substr($roman, 1);
+            $roman = trim(substr($roman, 1));
+            if ($roman === '') {
+                return ExcelError::NAN();
+            }
         }
 
         try {
-            $arabic = self::calculateArabic(str_split($roman));
+            $arabic = self::calculateArabic(mb_str_split($roman));
         } catch (Exception) {
             return ExcelError::VALUE(); // Invalid character detected
         }

src/PhpSpreadsheet/Reader/Security/XmlScanner.php

@@ -87,7 +87,7 @@ class XmlScanner
     public function scan($xml): string
     {
         // Don't rely purely on libxml_disable_entity_loader()
-        $pattern = '/\0*' . implode('\0*', str_split($this->pattern)) . '\0*/';
+        $pattern = '/\0*' . implode('\0*', mb_str_split($this->pattern)) . '\0*/';
 
         $xml = "$xml";
         if (preg_match($pattern, $xml)) {

tests/data/Calculation/Engineering/HEX2DEC.php

@@ -12,9 +12,7 @@ return [
     ['4886718345', '123456789'],
     [ExcelError::NAN(), '123.45'],
     ['0', '0'],
-    [11, 'A2'],
-    [0, 'A3'],
-    [0, ''],
+    ['0', ''],
     [ExcelError::NAN(), 'G3579A'],
     [ExcelError::VALUE(), true],
     [ExcelError::VALUE(), false],

tests/data/Calculation/Engineering/OCT2DEC.php

@@ -15,8 +15,6 @@ return [
     [ExcelError::NAN(), '3579'],
     ['44', '54'],
     ['-165', '7777777533'], // 2's Complement
-    ['65', 'A2'],
-    ['0', 'A3'],
     ['0', ''],
     [ExcelError::NAN(), '37777777770'], // too many digits
     ['536870911', '3777777777'], // highest positive

tests/data/Calculation/MathTrig/ARABIC.php

@@ -63,4 +63,8 @@ return [
         0,
         '',
     ],
+    [
+        '#NUM!',
+        '-',
+    ],
 ];