From 3794efe66210873ea4598aa3a276b8f5a795fec3 Mon Sep 17 00:00:00 2001
From: Christophe Coevoet <stof@notk.org>
Date: Sun, 9 Feb 2025 14:48:10 +0100
Subject: [PATCH] Fix support for ignoring syntax erros in an undefined handler
 in guard

---
 src/ExpressionParser.php                      | 23 ++++++++++++++--
 .../Fixtures/tags/guard/throwing_handler.test | 22 +++++++++++++++
 tests/IntegrationTest.php                     | 27 +++++++++++++++++++
 3 files changed, 70 insertions(+), 2 deletions(-)
 create mode 100644 tests/Fixtures/tags/guard/throwing_handler.test

diff --git a/src/ExpressionParser.php b/src/ExpressionParser.php
index d82e9c0e79a..233139ee4ab 100644
--- a/src/ExpressionParser.php
+++ b/src/ExpressionParser.php
@@ -799,7 +799,17 @@ private function getTest(int $line): TwigTest
 
     private function getFunction(string $name, int $line): TwigFunction
     {
-        if (!$function = $this->env->getFunction($name)) {
+        try {
+            $function = $this->env->getFunction($name);
+        } catch (SyntaxError $e) {
+            if (!$this->parser->shouldIgnoreUnknownTwigCallables()) {
+                throw $e;
+            }
+
+            $function = null;
+        }
+
+        if (!$function) {
             if ($this->parser->shouldIgnoreUnknownTwigCallables()) {
                 return new TwigFunction($name, fn () => '');
             }
@@ -819,7 +829,16 @@ private function getFunction(string $name, int $line): TwigFunction
 
     private function getFilter(string $name, int $line): TwigFilter
     {
-        if (!$filter = $this->env->getFilter($name)) {
+        try {
+            $filter = $this->env->getFilter($name);
+        } catch (SyntaxError $e) {
+            if (!$this->parser->shouldIgnoreUnknownTwigCallables()) {
+                throw $e;
+            }
+
+            $filter = null;
+        }
+        if (!$filter) {
             if ($this->parser->shouldIgnoreUnknownTwigCallables()) {
                 return new TwigFilter($name, fn () => '');
             }
diff --git a/tests/Fixtures/tags/guard/throwing_handler.test b/tests/Fixtures/tags/guard/throwing_handler.test
new file mode 100644
index 00000000000..37e32ef6c00
--- /dev/null
+++ b/tests/Fixtures/tags/guard/throwing_handler.test
@@ -0,0 +1,22 @@
+--TEST--
+"guard" creates a compilation time condition on Twig callables availability
+--TEMPLATE--
+{% guard filter throwing_undefined_filter %}
+    NEVER
+    {{ 'a'|throwing_undefined_filter }}
+{% else -%}
+    The throwing_undefined_filter filter doesn't exist
+{% endguard %}
+
+{% guard function throwing_undefined_function -%}
+    NEVER
+    {{ throwing_undefined_function() }}
+{% else -%}
+    The throwing_undefined_function function doesn't exist
+{% endguard %}
+--DATA--
+return []
+--EXPECT--
+The throwing_undefined_filter filter doesn't exist
+
+The throwing_undefined_function function doesn't exist
diff --git a/tests/IntegrationTest.php b/tests/IntegrationTest.php
index f4889cd754b..273324d1061 100644
--- a/tests/IntegrationTest.php
+++ b/tests/IntegrationTest.php
@@ -12,6 +12,7 @@
  */
 
 use Twig\DeprecatedCallableInfo;
+use Twig\Error\SyntaxError;
 use Twig\Extension\AbstractExtension;
 use Twig\Extension\DebugExtension;
 use Twig\Extension\SandboxExtension;
@@ -49,6 +50,32 @@ public function getExtensions()
         ];
     }
 
+    protected function getUndefinedFunctionCallbacks(): array
+    {
+        return [
+            static function (string $name) {
+                if ('throwing_undefined_function' === $name) {
+                    throw new SyntaxError('This function is undefined in the tests.');
+                }
+
+                return false;
+            },
+        ];
+    }
+
+    protected function getUndefinedTokenParserCallbacks(): array
+    {
+        return [
+            static function (string $name) {
+                if ('throwing_undefined_filter' === $name) {
+                    throw new SyntaxError('This filter is undefined in the tests.');
+                }
+
+                return false;
+            },
+        ];
+    }
+
     protected static function getFixturesDirectory(): string
     {
         return __DIR__.'/Fixtures/';