Fix behaviour that proper callables could change

Author: Girgias

ext/xml/tests/xml_set_object_multiple_times.phpt

@@ -15,6 +15,9 @@ class A {
         xml_set_object($parser, $b);
         echo "A::start_element($name)\n";
     }
+    public function PIHandler($parser, $target, $data) {
+        echo "A::PIHandler($target)\n";
+    }
 }
 
 class B {
@@ -24,6 +27,9 @@ class B {
     public function end_element($parser, $name) {
         echo "B::end_element($name)\n";
     }
+    public function PIHandler($parser, $target, $data) {
+        echo "B::PIHandler($target)\n";
+    }
 }
 
 $a = new A;
@@ -32,11 +38,13 @@ $b = new B;
 $parser = xml_parser_create();
 xml_set_object($parser, $a);
 xml_set_element_handler($parser, "start_element", "end_handler");
+xml_set_processing_instruction_handler($parser, [$a, "PIHandler"]);
 xml_parse($parser, <<<XML
 <?xml version="1.0"?>
 <container>
     <child/>
 </container>
+<?pi-test data ?>
 XML);
 
 ?>
@@ -45,3 +53,4 @@ A::start_element(CONTAINER)
 B::start_element(CHILD)
 end_handler(CHILD)
 end_handler(CONTAINER)
+A::PIHandler(pi-test)

ext/xml/xml.c

@@ -1078,15 +1078,20 @@ static bool php_xml_check_string_method_arg(
 	}
 
 	parser_handler_fcc->function_handler = method_ptr;
-	parser_handler_fcc->calling_scope = ce;
+	/* We set the calling scope to NULL to be able to differentiate a "method" set from a proper callable */
+	parser_handler_fcc->calling_scope = NULL;
 	parser_handler_fcc->called_scope = ce;
 	parser_handler_fcc->object = object;
 
 	return true;
 }
 
 #define PHP_XML_CHECK_NEW_THIS_METHODS(parser_to_check, new_this_obj, fcc_field) \
-	if (ZEND_FCC_INITIALIZED(parser_to_check->fcc_field) && parser_to_check->fcc_field.object == parser_to_check->object) { \
+	if ( \
+		ZEND_FCC_INITIALIZED(parser_to_check->fcc_field) \
+		&& parser_to_check->fcc_field.object == parser_to_check->object \
+		&& parser_to_check->fcc_field.calling_scope == NULL \
+	) { \
 		zend_string *method_name = zend_string_copy(parser_to_check->fcc_field.function_handler->common.function_name); \
 		zend_fcc_dtor(&parser_to_check->fcc_field); \
 		bool status = php_xml_check_string_method_arg(2, new_this_obj, method_name, &parser_to_check->fcc_field); \