From a2b023397eebdbbcae5fbb9cec5c6739d1f5d1ae Mon Sep 17 00:00:00 2001
From: Fabien Potencier <fabien@potencier.org>
Date: Sun, 23 Aug 2026 09:50:46 +0200
Subject: [PATCH] Fix an empty destructuring pattern triggering a PHP fatal
 error instead of a SyntaxError

---
 CHANGELOG                                     |  1 +
 .../Infix/AssignmentExpressionParser.php      |  3 +++
 tests/ExpressionParserTest.php                | 19 +++++++++++++++++++
 3 files changed, 23 insertions(+)

diff --git a/CHANGELOG b/CHANGELOG
index 185a82a6f..38e3176a4 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,7 @@
 # 3.29.0 (2026-XX-XX)
 
  * Add documentation comments to attach metadata to nodes (experimental)
+ * Fix an empty destructuring pattern triggering a PHP fatal error instead of a `SyntaxError`
  * Fix sequence destructuring of iterators throwing a `TypeError`
  * Add `TempestMarkdown` to use `tempest/markdown` as the `markdown_to_html` converter
  * Fix imported macros not resolving their own template-level macro imports
diff --git a/src/ExpressionParser/Infix/AssignmentExpressionParser.php b/src/ExpressionParser/Infix/AssignmentExpressionParser.php
index 291d68bf5..451d0f968 100644
--- a/src/ExpressionParser/Infix/AssignmentExpressionParser.php
+++ b/src/ExpressionParser/Infix/AssignmentExpressionParser.php
@@ -50,6 +50,9 @@ class AssignmentExpressionParser extends BinaryOperatorExpressionParser
         };
 
         if ($left instanceof ArrayExpression) {
+            if (!$left->getKeyValuePairs()) {
+                throw new SyntaxError('Cannot destructure to an empty list of variables.', $token->getLine(), $parser->getStream()->getSourceContext());
+            }
             foreach ($left->getKeyValuePairs() as $i => $pair) {
                 if ($pair['value'] instanceof ContextVariable && !$pair['value'] instanceof AssignContextVariable) {
                     $left->setNode(2 * $i + 1, new AssignContextVariable($pair['value']->getAttribute('name'), $pair['value']->getTemplateLine()));
diff --git a/tests/ExpressionParserTest.php b/tests/ExpressionParserTest.php
index dc69c812b..7709e2948 100644
--- a/tests/ExpressionParserTest.php
+++ b/tests/ExpressionParserTest.php
@@ -268,6 +268,25 @@ class ExpressionParserTest extends TestCase
         $this->assertSame('third', $pairs[2]['value']->getAttribute('name'));
     }
 
+    /**
+     * @dataProvider getEmptyDestructuringTests
+     */
+    #[DataProvider('getEmptyDestructuringTests')]
+    public function testEmptyDestructuringThrows(string $template): void
+    {
+        $env = new Environment(new ArrayLoader(), ['cache' => false, 'autoescape' => false]);
+
+        $this->expectException(SyntaxError::class);
+        $this->expectExceptionMessage('Cannot destructure to an empty list of variables');
+        $env->compileSource(new Source($template, 'index'));
+    }
+
+    public static function getEmptyDestructuringTests()
+    {
+        yield ['{% do [] = values %}'];
+        yield ['{% do {} = values %}'];
+    }
+
     public function testObjectDestructuringUsesAssignmentTargets(): void
     {
         $env = new Environment(new ArrayLoader(), ['cache' => false, 'autoescape' => false]);