Forbid unbinding $this from methods

Author: nikic

UPGRADING

@@ -30,6 +30,8 @@ PHP 8.0 UPGRADE NOTES
     argument to define() may no longer be true.
   . Removed create_function(). Anonymous functions may be used instead.
   . Removed each(). foreach or ArrayIterator should be used instead.
+  . Removed ability to unbind $this from closures that were created from a
+    method, using Closure::fromCallable() or ReflectionMethod::getClosure().
 
 - Filter:
   . The FILTER_FLAG_SCHEME_REQUIRED and FILTER_FLAG_HOST_REQUIRED flags for the

Zend/tests/bug70681.phpt

@@ -12,5 +12,5 @@ var_dump($c("foo"));
 
 ?>
 --EXPECTF--
-Warning: Cannot unbind $this of internal method in %s on line %d
+Warning: Cannot unbind $this of method in %s on line %d
 int(3)

Zend/tests/closure_061.phpt

@@ -175,9 +175,7 @@ Cannot rebind scope of closure created by ReflectionFunctionAbstract::getClosure
 -------------------
 
 bindTo(null, Cls::class):
-Unbinding $this of a method is deprecated
-
-Success!
+Cannot unbind $this of method
 
 bindTo(new Cls, Cls::class):
 Success!
@@ -210,10 +208,10 @@ bindTo(new ClsUnrelated, SplDoublyLinkedList::class):
 Cannot bind method SplDoublyLinkedList::count() to object of class ClsUnrelated
 
 bindTo(null, null):
-Cannot unbind $this of internal method
+Cannot unbind $this of method
 
 bindTo(null, SplDoublyLinkedList::class):
-Cannot unbind $this of internal method
+Cannot unbind $this of method
 
 bindTo(new SplDoublyLinkedList, null):
 Cannot rebind scope of closure created by ReflectionFunctionAbstract::getClosure()

Zend/zend_closures.c

@@ -84,12 +84,8 @@ static zend_bool zend_valid_closure_binding(
 		}
 	} else if (is_fake_closure && func->common.scope
 			&& !(func->common.fn_flags & ZEND_ACC_STATIC)) {
-		if (func->type == ZEND_INTERNAL_FUNCTION) {
-			zend_error(E_WARNING, "Cannot unbind $this of internal method");
-			return 0;
-		} else {
-			zend_error(E_DEPRECATED, "Unbinding $this of a method is deprecated");
-		}
+		zend_error(E_WARNING, "Cannot unbind $this of method");
+		return 0;
 	}
 
 	if (scope && scope != func->common.scope && scope->type == ZEND_INTERNAL_CLASS) {