MAGETWO-97040: Magento Framework Escaper - Critical log with special symbols

Author: Oleksandr Iegorov

lib/internal/Magento/Framework/Escaper.php

@@ -91,6 +91,7 @@ function ($errorNumber, $errorString) {
                         throw new \Exception($errorString, $errorNumber);
                     }
                 );
+                $data = $this->prepareUnescapedCharacters($data);
                 $string = mb_convert_encoding($data, 'HTML-ENTITIES', 'UTF-8');
                 try {
                     $domDocument->loadHTML(
@@ -119,6 +120,19 @@ function ($errorNumber, $errorString) {
         return $result;
     }
 
+    /**
+     * Used to replace characters, that mb_convert_encoding will not process
+     *
+     * @param string $data
+     * @return string|null
+     */
+    private function prepareUnescapedCharacters(string $data): ?string
+    {
+        $patterns = ['/\&/u'];
+        $replacements = ['&'];
+        return \preg_replace($patterns, $replacements, $data);
+    }
+
     /**
      * Remove not allowed tags
      *