Function preg_replace could return null in case of an error (#11)

CHANGELOG.md

@@ -22,7 +22,7 @@ All notable changes to this project will be documented in this file, in reverse
 
 ## Fixed
 
-- Nothing.
+- Throw exception when preg_replace in XML serialization returns null in case of invalid utf-8 string passed
 
 ## 1.0.2 - 2022-11-25
 

src/Serialization/MarcXml.php

@@ -176,6 +176,7 @@ public static function fromString(string $marc): array
      *
      * @param array $record Record data
      *
+     * @throws \Exception
      * @return string
      */
     public static function toString(array $record): string
@@ -230,11 +231,15 @@ public static function toString(array $record): string
         $xml->endDocument();
 
         // Strip illegal characters from XML:
-        return preg_replace(
+        $xmlString = preg_replace(
             '/[^\x{0009}\x{000a}\x{000d}\x{0020}-\x{D7FF}\x{E000}-\x{FFFD}]+/u',
             '',
             $xml->outputMemory(true)
         );
+        if ($xmlString === null) {
+            throw new \Exception('Error processing XML');
+        }
+        return $xmlString;
     }
 
     /**

tests/Serialization/MarcXmlTest.php

@@ -29,6 +29,8 @@
 
 namespace VuFindTest\Marc\Serialization;
 
+use VuFind\Marc\MarcReader;
+
 /**
  * MarcXml Test Class
  *
@@ -40,6 +42,8 @@
  */
 class MarcXmlTest extends \PHPUnit\Framework\TestCase
 {
+    use \VuFind\Marc\Test\Feature\FixtureTrait;
+
     /**
      * Test rewind
      *
@@ -63,4 +67,19 @@ public function testGetNextRecordWithoutFile()
         $class = new \VuFind\Marc\Serialization\MarcXml();
         $class->getNextRecord();
     }
+
+    /**
+     * Test bad record
+     *
+     * @return void
+     * @throws \Exception
+     */
+    public function testToStringException()
+    {
+        $xmlFile = $this->getFixture('marc/bad.mrc');
+        $reader = new MarcReader($xmlFile);
+        $this->expectException(\Exception::class);
+        $this->expectExceptionMessage('Error processing XML');
+        $xml = $reader->toFormat('MARCXML');
+    }
 }