Fix leak if attribute arg evaluation fails while printing

Author: nikic

ext/reflection/php_reflection.c

@@ -6430,6 +6430,7 @@ ZEND_METHOD(ReflectionAttribute, __toString)
 		for (uint32_t i = 0; i < attr->data->argc; i++) {
 			zval tmp;
 			if (FAILURE == zend_get_attribute_value(&tmp, attr->data, i, attr->scope)) {
+				smart_str_free(&str);
 				RETURN_THROWS();
 			}
 
@@ -6440,7 +6441,9 @@ ZEND_METHOD(ReflectionAttribute, __toString)
 			}
 
 			if (format_default_value(&str, &tmp, NULL) == FAILURE) {
-				return;
+				zval_ptr_dtor(&tmp);
+				smart_str_free(&str);
+				RETURN_THROWS();
 			}
 
 			smart_str_appends(&str, " ]\n");

ext/reflection/tests/ReflectionAttribute_toString.phpt

@@ -3,14 +3,21 @@ ReflectionAttribute::__toString
 --FILE--
 <?php
 
-#[Foo, Bar(a: "foo", b: 1234), Baz("foo", 1234)]
+#[Foo, Bar(a: "foo", b: 1234), Baz("foo", 1234), XXX(ERROR)]
 function foo() {}
 
 $refl = new ReflectionFunction('foo');
 echo $refl->getAttributes()[0];
 echo $refl->getAttributes()[1];
 echo $refl->getAttributes()[2];
---EXPECTF--
+try {
+    echo $refl->getAttributes()[3];
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+
+?>
+--EXPECT--
 Attribute [ Foo ]
 Attribute [ Bar ] {
   - Arguments [2] {
@@ -24,3 +31,4 @@ Attribute [ Baz ] {
     Argument #1 [ 1234 ]
   }
 }
+Undefined constant "ERROR"