@@ -1,6 +1,6 @@

 * 2.12.5 (2020-XX-XX)

- * n/a

+ * Add a check to ensure that iconv() is defined

 * 2.12.4 (2020-02-11)

@@ -411,7 +411,7 @@ function twig_random(Environment $env, $values = null, $max = null)

         $charset = $env->getCharset();

         if ('UTF-8' !== $charset) {

-            $values = iconv($charset, 'UTF-8', $values);

+            $values = twig_convert_encoding($values, 'UTF-8', $charset);

         }

         // unicode version of str_split()

@@ -420,7 +420,7 @@ function twig_random(Environment $env, $values = null, $max = null)

         if ('UTF-8' !== $charset) {

             foreach ($values as $i => $value) {

-                $values[$i] = iconv('UTF-8', $charset, $value);

+                $values[$i] = twig_convert_encoding($value, $charset, 'UTF-8');

             }

         }

     }

@@ -885,7 +885,7 @@ function twig_reverse_filter(Environment $env, $item, $preserveKeys = false)

     $charset = $env->getCharset();

     if ('UTF-8' !== $charset) {

-        $item = iconv($charset, 'UTF-8', $string);

+        $item = twig_convert_encoding($string, 'UTF-8', $charset);

     }

     preg_match_all('/./us', $item, $matches);

@@ -893,7 +893,7 @@ function twig_reverse_filter(Environment $env, $item, $preserveKeys = false)

     $string = implode('', array_reverse($matches[0]));

     if ('UTF-8' !== $charset) {

-        $string = iconv('UTF-8', $charset, $string);

+        $string = twig_convert_encoding($string, $charset, 'UTF-8');

     }

     return $string;

@@ -997,6 +997,10 @@ function twig_spaceless($content)

 function twig_convert_encoding($string, $to, $from)

 {

+    if (!function_exists('iconv')) {

+        throw new RuntimeError('Unable to convert encoding: required function iconv() does not exist. You should install ext-iconv or symfony/polyfill-iconv.');

+    }

+

     return iconv($from, $to, $string);

 }

@@ -244,7 +244,7 @@ function twig_escape_filter(Environment $env, $string, $strategy = 'html', $char

                 return htmlspecialchars($string, ENT_QUOTES | ENT_SUBSTITUTE, $charset);

             }

-            $string = iconv($charset, 'UTF-8', $string);

+            $string = twig_convert_encoding($string, 'UTF-8', $charset);

             $string = htmlspecialchars($string, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');

             return iconv('UTF-8', $charset, $string);

@@ -253,7 +253,7 @@ function twig_escape_filter(Environment $env, $string, $strategy = 'html', $char

             // escape all non-alphanumeric characters

             // into their \x or \uHHHH representations

             if ('UTF-8' !== $charset) {

-                $string = iconv($charset, 'UTF-8', $string);

+                $string = twig_convert_encoding($string, 'UTF-8', $charset);

             }

             if (!preg_match('//u', $string)) {

@@ -301,7 +301,7 @@ function twig_escape_filter(Environment $env, $string, $strategy = 'html', $char

         case 'css':

             if ('UTF-8' !== $charset) {

-                $string = iconv($charset, 'UTF-8', $string);

+                $string = twig_convert_encoding($string, 'UTF-8', $charset);

             }

             if (!preg_match('//u', $string)) {

@@ -322,7 +322,7 @@ function twig_escape_filter(Environment $env, $string, $strategy = 'html', $char

         case 'html_attr':

             if ('UTF-8' !== $charset) {

-                $string = iconv($charset, 'UTF-8', $string);

+                $string = twig_convert_encoding($string, 'UTF-8', $charset);

             }

             if (!preg_match('//u', $string)) {