From d851c12199933fddc0d30d75875b2e7144ede7e3 Mon Sep 17 00:00:00 2001
From: Richard Lobb <trampgeek@gmail.com>
Date: Sun, 30 Jun 2024 11:35:17 +1200
Subject: [PATCH] Catch all errors on a call to Twig render and rethrow as Twig
 Errors. [Some Twig code was giving PHP errors in PHP8]

---
 classes/twig.php | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/classes/twig.php b/classes/twig.php
index 73659843a..5bc58b8e7 100644
--- a/classes/twig.php
+++ b/classes/twig.php
@@ -88,8 +88,9 @@ private static function get_twig_environment($isstrict = false, $isdebug = false
     // which is added the STUDENT parameter.
     // Return the Twig-expanded string.
     // Any Twig exceptions raised must be caught higher up.
-    // Since Twig range functions can result in PHP ValueError being thrown (grr)
-    // ValueErrors are caught and re-thrown as TwigErrors.
+    // Since Twig range functions can result in PHP ValueError being thrown, and
+    // a call to the slice filter with a string parameter gives an error.
+    // So all errors are caught and re-thrown as TwigErrors.
     public static function render($s, $student, $parameters = [], $isstrict = false) {
         if ($s === null || trim($s) === '') {
             return '';
@@ -103,7 +104,7 @@ public static function render($s, $student, $parameters = [], $isstrict = false)
         $template = $twig->createTemplate($s);
         try {
             $renderedstring = $template->render($parameters);
-        } catch (ValueError $e) {
+        } catch (Error $e) {
             throw new \Twig\Error\Error("Twig error: " . $e->getMessage());
         }
         return $renderedstring;