Merge branch 'PHP-7.4'

* PHP-7.4:
  Fixed bug #79839

Author: nikic

ext/standard/array.c

@@ -1391,6 +1391,16 @@ static int php_array_walk(zval *array, zval *userdata, int recursive) /* {{{ */
 				zend_hash_move_forward_ex(target_hash, &pos);
 				continue;
 			}
+
+			/* Add type source for property references. */
+			if (Z_TYPE_P(zv) != IS_REFERENCE && Z_TYPE_P(array) == IS_OBJECT) {
+				zend_property_info *prop_info =
+					zend_get_typed_property_info_for_slot(Z_OBJ_P(array), zv);
+				if (prop_info) {
+					ZVAL_NEW_REF(zv, zv);
+					ZEND_REF_ADD_TYPE_SOURCE(Z_REF_P(zv), prop_info);
+				}
+			}
 		}
 
 		/* Ensure the value is a reference. Otherwise the location of the value may be freed. */

ext/standard/tests/array/bug79839.phpt

@@ -0,0 +1,26 @@
+--TEST--
+Bug #79839: array_walk() does not respect property types
+--FILE--
+<?php
+
+class Test {
+    public int $prop = 42;
+}
+
+$test = new Test;
+try {
+    array_walk($test, function(&$ref) {
+        $ref = []; // Should throw
+    });
+} catch (TypeError $e) {
+    echo $e->getMessage(), "\n";
+}
+var_dump($test);
+
+?>
+--EXPECT--
+Cannot assign array to reference held by property Test::$prop of type int
+object(Test)#1 (1) {
+  ["prop"]=>
+  &int(42)
+}