https://github.com/php/php-src/issues/12965     Build Failure With libxml2-2.12.3 #12965
https://github.com/php/php-src/commit/0a39890   Fix libxml2 2.12 build due to API breaks
https://github.com/php/php-src/commit/8a95e61   Fix GH-12702: libxml2 2.12.0 issue building from src

/ext/xml/compat.c:569:35: warning: 'lastError' is deprecated [-Wdeprecated-declarations]
/opt/local/include/libxml2/libxml/parser.h:597:24: note: 'lastError' has been explicitly marked deprecated here
return !error && parser->parser->lastError.level <= XML_ERR_WARNING;
backporting from php81

--- a/ext/dom/document.c
+++ b/ext/dom/document.c
@@ -25,6 +25,7 @@
 #if HAVE_LIBXML && HAVE_DOM
 #include "php_dom.h"
 #include <libxml/SAX.h>
+#include <libxml/xmlsave.h>
 #ifdef LIBXML_SCHEMAS_ENABLED
 #include <libxml/relaxng.h>
 #include <libxml/xmlschemas.h>
--- a/ext/libxml/php_libxml.h
+++ b/ext/libxml/php_libxml.h
@@ -37,6 +37,7 @@ extern zend_module_entry libxml_module_entry;
 
 #include "zend_smart_str.h"
 #include <libxml/tree.h>
+#include <libxml/parser.h>
 
 #define LIBXML_SAVE_NOEMPTYTAG 1<<2
 
--- a/ext/soap/php_sdl.c
+++ b/ext/soap/php_sdl.c
@@ -333,7 +333,7 @@ static void load_wsdl_ex(zval *this_ptr, char *struri, sdlCtx *ctx, int include)
 	sdl_restore_uri_credentials(ctx);
 
 	if (!wsdl) {
-		xmlErrorPtr xmlErrorPtr = xmlGetLastError();
+		const xmlError *xmlErrorPtr = xmlGetLastError();
 
 		if (xmlErrorPtr) {
 			soap_error2(E_ERROR, "Parsing WSDL: Couldn't load from '%s' : %s", struri, xmlErrorPtr->message);
--- a/ext/libxml/libxml.c
+++ b/ext/libxml/libxml.c
@@ -476,7 +476,7 @@ php_libxml_input_buffer_create_filename(const char *URI, xmlCharEncoding enc)
 static xmlOutputBufferPtr
 php_libxml_output_buffer_create_filename(const char *URI,
                               xmlCharEncodingHandlerPtr encoder,
-                              int compression ATTRIBUTE_UNUSED)
+                              int compression __attribute__((__unused__)))
 {
 	xmlOutputBufferPtr ret;
 	xmlURIPtr puri;
--- a/ext/libxml/libxml.c
+++ b/ext/libxml/libxml.c
@@ -530,7 +530,11 @@ static int _php_libxml_free_error(xmlErrorPtr error)
 	return 1;
 }
 
-static void _php_list_set_error_structure(xmlErrorPtr error, const char *msg)
+#if LIBXML_VERSION >= 21200
+static void _php_list_set_error_structure(const xmlError *error, const char *msg)
+#else
+static void _php_list_set_error_structure(xmlError *error, const char *msg)
+#endif
 {
 	xmlError error_copy;
 	int ret;
@@ -782,7 +786,11 @@ PHP_LIBXML_API void php_libxml_ctx_warning(void *ctx, const char *msg, ...)
 	va_end(args);
 }
 
+#if LIBXML_VERSION >= 21200
+PHP_LIBXML_API void php_libxml_structured_error_handler(void *userData, const xmlError *error)
+#else
 PHP_LIBXML_API void php_libxml_structured_error_handler(void *userData, xmlErrorPtr error)
+#endif
 {
 	_php_list_set_error_structure(error, NULL);
 
--- a/ext/libxml/libxml.c
+++ b/ext/libxml/libxml.c
@@ -1069,9 +1069,7 @@ static PHP_FUNCTION(libxml_use_internal_errors)
    Retrieve last error from libxml */
 static PHP_FUNCTION(libxml_get_last_error)
 {
-	xmlErrorPtr error;
-
-	error = xmlGetLastError();
+	const xmlError *error = xmlGetLastError();
 
 	if (error) {
 		object_init_ex(return_value, libxmlerror_class_entry);
--- a/ext/xml/compat.c	2026-04-10 10:23:52
+++ b/ext/xml/compat.c	2026-04-10 10:19:04
@@ -563,10 +563,14 @@
 PHP_XML_API int
 XML_Parse(XML_Parser parser, const XML_Char *data, int data_len, int is_final)
 {
-	int error;
+	int error = xmlParseChunk(parser->parser, (char *) data, data_len, is_final);
 
-	error = xmlParseChunk(parser->parser, (char *) data, data_len, is_final);
-	return !error && parser->parser->lastError.level <= XML_ERR_WARNING;
+	if (!error) {
+		const xmlError *error_data = xmlCtxtGetLastError(parser->parser);
+		return !error_data || error_data->level <= XML_ERR_WARNING;
+	}
+
+	return 0;
 }
 
 PHP_XML_API int
