Make sure to load the class for object variance

Author: nikic

Zend/tests/type_declarations/variance/enum_forward_compat.phpt

@@ -0,0 +1,26 @@
+--TEST--
+Forward compatibility with types that look like classes but aren't
+--FILE--
+<?php
+
+spl_autoload_register(function($class) {
+    var_dump($class);
+    if ($class === 'X') {
+        class X {}
+    } else {
+        class Y {}
+    }
+});
+
+class A {
+    public function method(X $param) : object {}
+}
+
+class B extends A {
+    public function method(object $param) : Y {}
+}
+
+?>
+--EXPECT--
+string(1) "Y"
+string(1) "X"

Zend/zend_inheritance.c

@@ -320,7 +320,8 @@ _inheritance_status _check_covariance(
 				code = INHERITANCE_UNRESOLVED;
 			}
 		} else if (proto_type_code == IS_OBJECT) {
-			code = INHERITANCE_SUCCESS;
+			zend_class_entry *fe_ce = lookup_class(fe_class_name);
+			code = fe_ce ? INHERITANCE_SUCCESS : INHERITANCE_UNRESOLVED;
 		} else {
 			code = INHERITANCE_ERROR;
 		}