fix checking covariant on override static with self & add tests for overriding static with self in non-final classes

Author: rekmixa

Zend/tests/type_declarations/override_static_type_with_self_in_non_final_class_with_abstract_class.phpt

@@ -0,0 +1,24 @@
+--TEST--
+Overriding static return types with self in non-final class with abstract class
+--FILE--
+<?php
+
+abstract class B
+{
+    abstract public function method2(): static;
+}
+
+class Foo extends B
+{
+    public function method2(): self
+    {
+        return $this;
+    }
+}
+
+$foo = new Foo();
+
+var_dump($foo->method2());
+?>
+--EXPECT--
+Fatal error: Declaration of Foo::method2(): Foo must be compatible with B::method2(): static in /app/Zend/tests/type_declarations/override_static_type_with_self_in_non_final_class_with_abstract_class.php on line 10

Zend/tests/type_declarations/override_static_type_with_self_in_non_final_class_with_interface.phpt

@@ -0,0 +1,24 @@
+--TEST--
+Overriding static return types with self in non-final class with interface
+--FILE--
+<?php
+
+interface A
+{
+    public function method1(): static;
+}
+
+class Foo implements A
+{
+    public function method1(): self
+    {
+        return $this;
+    }
+}
+
+$foo = new Foo();
+
+var_dump($foo->method1());
+?>
+--EXPECT--
+Fatal error: Declaration of Foo::method1(): Foo must be compatible with A::method1(): static in /app/Zend/tests/type_declarations/override_static_type_with_self_in_non_final_class_with_interface.php on line 10

Zend/tests/type_declarations/override_static_type_with_self_in_non_final_class_with_trait.phpt

@@ -0,0 +1,26 @@
+--TEST--
+Overriding static return types with self in non-final class with trait
+--FILE--
+<?php
+
+trait C
+{
+    abstract public function method3(): static;
+}
+
+class Foo
+{
+    use C;
+
+    public function method3(): self
+    {
+        return $this;
+    }
+}
+
+$foo = new Foo();
+
+var_dump($foo->method3());
+?>
+--EXPECT--
+Fatal error: Declaration of Foo::method3(): Foo must be compatible with C::method3(): static in /app/Zend/tests/type_declarations/override_static_type_with_self_in_non_final_class_with_trait.php on line 12

Zend/zend_inheritance.c

@@ -677,20 +677,21 @@ ZEND_API inheritance_status zend_perform_covariant_type_check(
 	uint32_t fe_type_mask = ZEND_TYPE_PURE_MASK(fe_type);
 	uint32_t proto_type_mask = ZEND_TYPE_PURE_MASK(proto_type);
 	uint32_t added_types = fe_type_mask & ~proto_type_mask;
+
+	if (proto_type_mask & MAY_BE_STATIC && fe_type_mask | MAY_BE_STATIC &&
+		fe_scope->ce_flags & ZEND_ACC_FINAL &&
+		instanceof_function(fe_scope, proto_scope)) {
+		/* Replacing type that accepts static with self in final classes is okay */
+		return INHERITANCE_SUCCESS;
+	}
+
 	if (added_types) {
 		if ((added_types & MAY_BE_STATIC)
 				&& zend_type_permits_self(proto_type, proto_scope, fe_scope)) {
 			/* Replacing type that accepts self with static is okay */
 			added_types &= ~MAY_BE_STATIC;
 		}
 
-		if (proto_type_mask & MAY_BE_STATIC && fe_type_mask | MAY_BE_STATIC &&
-			fe_scope->ce_flags & ZEND_ACC_FINAL &&
-			zend_is_intersection_subtype_of_type(fe_scope, fe_type, proto_scope, proto_type) == INHERITANCE_SUCCESS) {
-			/* Replacing type that accepts static with self in final classes is okay */
-			return INHERITANCE_SUCCESS
-		}
-
 		if (added_types == MAY_BE_NEVER) {
 			/* never is the bottom type */
 			return INHERITANCE_SUCCESS;