src/Translator.php

@@ -3242,6 +3242,7 @@ CODE;
             return $arg->typeCheck;
         }
 
+        $declaredClass = $arg->declaredClass ?: $arg->class;
         return match ($arg->type) {
             Type::INT => [['kind' => 'isInt']],
             Type::FLOAT => [['kind' => 'isFloat']],
@@ -3249,8 +3250,8 @@ CODE;
             Type::STR => [['kind' => 'isString']],
             Type::ARRAY => [['kind' => 'isArray']],
             Type::RESOURCE => [['kind' => 'isResource']],
-            Type::OBJECT => $arg->class
-                ? [['kind' => 'instanceof', 'class' => $arg->class]]
+            Type::OBJECT => $declaredClass
+                ? [['kind' => 'instanceof', 'class' => $declaredClass]]
                 : [['kind' => 'isObject']],
             default => null,
         };

tests/compiler/namespace/interface-impl-param-type-cross-ns.phpt

@@ -0,0 +1,62 @@
+--TEST--
+Cross-namespace interface implementation parameter compatibility is declaration-order independent
+--FILE--
+<?php
+namespace A {
+    use B\I0;
+    use B\I1;
+    use B\I2;
+
+    abstract class Test implements I2
+    {
+        public function test(I1 $a): bool
+        {
+            return true;
+        }
+
+        public function testParent(I0 $a): bool
+        {
+            return true;
+        }
+    }
+}
+
+namespace B {
+    interface I0
+    {
+    }
+
+    interface I1 extends I0
+    {
+    }
+
+    interface I2
+    {
+        public function test(I1 $a): bool;
+
+        public function testParent(I1 $a): bool;
+    }
+
+    class Impl1 implements I1
+    {
+    }
+}
+
+namespace {
+    class Concrete extends \A\Test
+    {
+    }
+
+    function main()
+    {
+        $obj = new Concrete();
+        var_dump($obj->test(new \B\Impl1()));
+        var_dump($obj->testParent(new \B\Impl1()));
+        echo "done\n";
+    }
+}
+?>
+--EXPECT--
+bool(true)
+bool(true)
+done