Changes

vendor/phpoffice/math/src/Math/Reader/MathML.php

@@ -10,6 +10,7 @@ use PhpOffice\Math\Element;
 use PhpOffice\Math\Exception\InvalidInputException;
 use PhpOffice\Math\Exception\NotImplementedException;
 use PhpOffice\Math\Math;
+use PhpOffice\Math\Reader\Security\XmlScanner;
 
 class MathML implements ReaderInterface
 {
@@ -22,8 +23,17 @@ class MathML implements ReaderInterface
     /** @var DOMXPath */
     private $xpath;
 
+    /** @var XmlScanner */
+    private $xmlScanner;
+
+    public function __construct()
+    {
+        $this->xmlScanner = XmlScanner::getInstance();
+    }
+
     public function read(string $content): ?Math
     {
+        $content = $this->xmlScanner->scan($content);
         $content = str_replace(
             [
                 '⁢',
@@ -35,7 +45,7 @@ class MathML implements ReaderInterface
         );
 
         $this->dom = new DOMDocument();
-        $this->dom->loadXML($content, LIBXML_DTDLOAD);
+        $this->dom->loadXML($content);
 
         $this->math = new Math();
         $this->parseNode(null, $this->math);

vendor/phpoffice/math/src/Math/Writer/MathML.php

@@ -40,6 +40,26 @@ class MathML implements WriterInterface
     {
         $tagName = $this->getElementTagName($element);
 
+        // Element\AbstractGroupElement
+        if ($element instanceof Element\Semantics) {
+            $this->output->startElement($tagName);
+            // Write elements
+            foreach ($element->getElements() as $childElement) {
+                $this->writeElementItem($childElement);
+            }
+
+            // Write annotations
+            foreach ($element->getAnnotations() as $encoding => $annotation) {
+                $this->output->startElement('annotation');
+                $this->output->writeAttribute('encoding', $encoding);
+                $this->output->text($annotation);
+                $this->output->endElement();
+            }
+            $this->output->endElement();
+
+            return;
+        }
+
         // Element\AbstractGroupElement
         if ($element instanceof Element\AbstractGroupElement) {
             $this->output->startElement($tagName);
@@ -121,6 +141,9 @@ class MathML implements WriterInterface
         if ($element instanceof Element\Operator) {
             return 'mo';
         }
+        if ($element instanceof Element\Semantics) {
+            return 'semantics';
+        }
 
         throw new NotImplementedException(sprintf(
             '%s : The element of the class `%s` has no tag name',