Add libxml_get_external_entity_loader()

UPGRADING

@@ -221,6 +221,9 @@ PHP 8.2 UPGRADE NOTES
 - Curl:
   . curl_upkeep() (libcurl >= 7.62.0)
 
+- libxml:
+  . libxml_get_external_entity_loader()
+
 - mysqli:
   . mysqli_execute_query()
 

Zend/zend_API.h

@@ -1528,6 +1528,10 @@ ZEND_API ZEND_COLD void zend_argument_value_error(uint32_t arg_num, const char *
 		SEPARATE_ZVAL_NOREF(_arg); \
 	}
 
+/* get the zval* for a previously parsed argument */
+#define Z_PARAM_GET_PREV_ZVAL(dest) \
+	zend_parse_arg_zval_deref(_arg, &dest, 0);
+
 /* old "|" */
 #define Z_PARAM_OPTIONAL \
 	_optional = 1;
@@ -1690,6 +1694,10 @@ ZEND_API ZEND_COLD void zend_argument_value_error(uint32_t arg_num, const char *
 #define Z_PARAM_FUNC_OR_NULL(dest_fci, dest_fcc) \
 	Z_PARAM_FUNC_EX(dest_fci, dest_fcc, 1, 0)
 
+#define Z_PARAM_FUNC_OR_NULL_WITH_ZVAL(dest_fci, dest_fcc, dest_zp) \
+	Z_PARAM_FUNC_EX(dest_fci, dest_fcc, 1, 0) \
+	Z_PARAM_GET_PREV_ZVAL(dest_zp)
+
 /* old "h" */
 #define Z_PARAM_ARRAY_HT_EX2(dest, check_null, deref, separate) \
 		Z_PARAM_PROLOGUE(deref, separate); \

ext/libxml/libxml.c

@@ -228,23 +228,11 @@ static PHP_GINIT_FUNCTION(libxml)
 	ZVAL_UNDEF(&libxml_globals->stream_context);
 	libxml_globals->error_buffer.s = NULL;
 	libxml_globals->error_list = NULL;
-	ZVAL_UNDEF(&libxml_globals->entity_loader.object);
+	ZVAL_NULL(&libxml_globals->entity_loader.callback);
 	libxml_globals->entity_loader.fci.size = 0;
 	libxml_globals->entity_loader_disabled = 0;
 }
 
-static void _php_libxml_destroy_fci(zend_fcall_info *fci, zval *object)
-{
-	if (fci->size > 0) {
-		zval_ptr_dtor(&fci->function_name);
-		fci->size = 0;
-	}
-	if (!Z_ISUNDEF_P(object)) {
-		zval_ptr_dtor(object);
-		ZVAL_UNDEF(object);
-	}
-}
-
 /* Channel libxml file io layer through the PHP streams subsystem.
  * This allows use of ftps:// and https:// urls */
 
@@ -851,7 +839,9 @@ static PHP_RINIT_FUNCTION(libxml)
 
 static PHP_RSHUTDOWN_FUNCTION(libxml)
 {
-	_php_libxml_destroy_fci(&LIBXML(entity_loader).fci, &LIBXML(entity_loader).object);
+	LIBXML(entity_loader).fci.size = 0;
+	zval_ptr_dtor_nogc(&LIBXML(entity_loader).callback);
+	ZVAL_NULL(&LIBXML(entity_loader).callback);
 
 	return SUCCESS;
 }
@@ -1071,29 +1061,36 @@ PHP_FUNCTION(libxml_disable_entity_loader)
 /* {{{ Changes the default external entity loader */
 PHP_FUNCTION(libxml_set_external_entity_loader)
 {
+	zval					*callback;
 	zend_fcall_info			fci;
 	zend_fcall_info_cache	fcc;
 
 	ZEND_PARSE_PARAMETERS_START(1, 1)
-		Z_PARAM_FUNC_OR_NULL(fci, fcc)
+		Z_PARAM_FUNC_OR_NULL_WITH_ZVAL(fci, fcc, callback)
 	ZEND_PARSE_PARAMETERS_END();
 
-	_php_libxml_destroy_fci(&LIBXML(entity_loader).fci, &LIBXML(entity_loader).object);
-
 	if (ZEND_FCI_INITIALIZED(fci)) { /* argument not null */
 		LIBXML(entity_loader).fci = fci;
-		Z_ADDREF(fci.function_name);
-		if (fci.object != NULL) {
-			ZVAL_OBJ(&LIBXML(entity_loader).object, fci.object);
-			Z_ADDREF(LIBXML(entity_loader).object);
-		}
 		LIBXML(entity_loader).fcc = fcc;
+	} else {
+		LIBXML(entity_loader).fci.size = 0;
 	}
-
+	if (!Z_ISNULL(LIBXML(entity_loader).callback)) {
+		zval_ptr_dtor_nogc(&LIBXML(entity_loader).callback);
+	}
+	ZVAL_COPY(&LIBXML(entity_loader).callback, callback);
 	RETURN_TRUE;
 }
 /* }}} */
 
+/* {{{ Get the current external entity loader, or null if the default loader is installer. */
+PHP_FUNCTION(libxml_get_external_entity_loader)
+{
+	ZEND_PARSE_PARAMETERS_NONE();
+	RETURN_COPY(&LIBXML(entity_loader).callback);
+}
+/* }}} */
+
 /* {{{ Common functions shared by extensions */
 int php_libxml_xmlCheckUTF8(const unsigned char *s)
 {

ext/libxml/libxml.stub.php

@@ -177,3 +177,5 @@ function libxml_clear_errors(): void {}
 function libxml_disable_entity_loader(bool $disable = true): bool {}
 
 function libxml_set_external_entity_loader(?callable $resolver_function): bool {}
+
+function libxml_get_external_entity_loader(): ?callable {}

ext/libxml/php_libxml.h

@@ -43,8 +43,8 @@ ZEND_BEGIN_MODULE_GLOBALS(libxml)
 	smart_str error_buffer;
 	zend_llist *error_list;
 	struct _php_libxml_entity_resolver {
-		zval                    object;
-		zend_fcall_info			fci;
+		zval 					callback;
+		zend_fcall_info 		fci;
 		zend_fcall_info_cache	fcc;
 	} entity_loader;
 	bool entity_loader_disabled;

ext/libxml/tests/libxml_get_external_entity_loader.phpt

@@ -0,0 +1,36 @@
+--TEST--
+libxml_get_external_entity_loader() returns current handler
+--EXTENSIONS--
+libxml
+--FILE--
+<?php
+
+class Handler {
+	private $name;
+
+	public function __construct($name) {
+		$this->name = $name;
+	}
+
+	public function handle($public, $system, $context) {
+		return null;
+	}
+
+	public function __toString() {
+		return "Handler#{$this->name}";
+	}
+}
+
+var_dump(libxml_get_external_entity_loader());
+libxml_set_external_entity_loader([new Handler('A'), 'handle']);
+print libxml_get_external_entity_loader()[0] . "\n";
+libxml_set_external_entity_loader([new Handler('B'), 'handle']);
+print libxml_get_external_entity_loader()[0] . "\n";
+libxml_set_external_entity_loader(null);
+var_dump(libxml_get_external_entity_loader());
+
+--EXPECT--
+NULL
+Handler#A
+Handler#B
+NULL

ext/libxml/tests/libxml_set_external_entity_loader_error2.phpt

@@ -0,0 +1,14 @@
+--TEST--
+libxml_set_external_entity_loader() with non-callable argument
+--EXTENSIONS--
+libxml
+--FILE--
+<?php
+try {
+	libxml_set_external_entity_loader('nonexistent_function');
+} catch (Throwable $e) {
+	echo "Exception: " . $e->getMessage() . "\n";
+}
+?>
+--EXPECT--
+Exception: libxml_set_external_entity_loader(): Argument #1 ($resolver_function) must be a valid callback or null, function "nonexistent_function" not found or invalid function name