Implement LIBXML_NOXMLDECL

Fixes GH-11792.

Author: nielsdos

ext/dom/document.c

@@ -23,6 +23,7 @@
 #if defined(HAVE_LIBXML) && defined(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>
@@ -1461,8 +1462,7 @@ PHP_METHOD(DOMDocument, saveXML)
 	zval *id, *nodep = NULL;
 	xmlDoc *docp;
 	xmlNode *node;
-	xmlBufferPtr buf;
-	xmlChar *mem;
+	const char *mem;
 	dom_object *intern, *nodeobj;
 	int size, format, saveempty = 0;
 	zend_long options = 0;
@@ -1477,18 +1477,20 @@ PHP_METHOD(DOMDocument, saveXML)
 	libxml_doc_props const* doc_props = dom_get_doc_props_read_only(intern->document);
 	format = doc_props->formatoutput;
 
+	xmlBufferPtr buf = xmlBufferCreate();
+	if (!buf) {
+		php_error_docref(NULL, E_WARNING, "Could not fetch buffer");
+		RETURN_FALSE;
+	}
+
 	if (nodep != NULL) {
 		/* Dump contents of Node */
 		DOM_GET_OBJ(node, nodep, xmlNodePtr, nodeobj);
 		if (node->doc != docp) {
+			xmlBufferFree(buf);
 			php_dom_throw_error(WRONG_DOCUMENT_ERR, dom_get_strict_error(intern->document));
 			RETURN_FALSE;
 		}
-		buf = xmlBufferCreate();
-		if (!buf) {
-			php_error_docref(NULL, E_WARNING, "Could not fetch buffer");
-			RETURN_FALSE;
-		}
 		if (options & LIBXML_SAVE_NOEMPTYTAG) {
 			saveempty = xmlSaveNoEmptyTags;
 			xmlSaveNoEmptyTags = 1;
@@ -1497,29 +1499,45 @@ PHP_METHOD(DOMDocument, saveXML)
 		if (options & LIBXML_SAVE_NOEMPTYTAG) {
 			xmlSaveNoEmptyTags = saveempty;
 		}
-		mem = (xmlChar*) xmlBufferContent(buf);
-		if (!mem) {
-			xmlBufferFree(buf);
-			RETURN_FALSE;
-		}
-		RETVAL_STRING((char *) mem);
-		xmlBufferFree(buf);
 	} else {
 		if (options & LIBXML_SAVE_NOEMPTYTAG) {
 			saveempty = xmlSaveNoEmptyTags;
 			xmlSaveNoEmptyTags = 1;
 		}
+		int convertedOptions = XML_SAVE_AS_XML;
+		if (options & XML_SAVE_NO_DECL) {
+			convertedOptions |= XML_SAVE_NO_DECL;
+		}
+		if (format) {
+			convertedOptions |= XML_SAVE_FORMAT;
+		}
 		/* Encoding is handled from the encoding property set on the document */
-		xmlDocDumpFormatMemory(docp, &mem, &size, format);
+		xmlSaveCtxtPtr ctxt = xmlSaveToBuffer(buf, (const char *) docp->encoding, convertedOptions);
 		if (options & LIBXML_SAVE_NOEMPTYTAG) {
 			xmlSaveNoEmptyTags = saveempty;
 		}
-		if (!size || !mem) {
+		if (UNEXPECTED(!ctxt)) {
+			xmlBufferFree(buf);
+			php_error_docref(NULL, E_WARNING, "Could not create save context");
 			RETURN_FALSE;
 		}
-		RETVAL_STRINGL((char *) mem, size);
-		xmlFree(mem);
+		if (UNEXPECTED(xmlSaveDoc(ctxt, docp) < 0)) {
+			xmlBufferFree(buf);
+			(void) xmlSaveClose(ctxt);
+			php_error_docref(NULL, E_WARNING, "Could not save document");
+			RETURN_FALSE;
+		}
+		(void) xmlSaveFlush(ctxt);
+		(void) xmlSaveClose(ctxt);
+	}
+	mem = (const char *) xmlBufferContent(buf);
+	if (!mem) {
+		xmlBufferFree(buf);
+		RETURN_FALSE;
 	}
+	size = xmlBufferLength(buf);
+	RETVAL_STRINGL(mem, size);
+	xmlBufferFree(buf);
 }
 /* }}} end dom_document_savexml */
 

ext/dom/tests/DOMDocument_saveXML_XML_SAVE_NO_DECL.phpt

@@ -0,0 +1,24 @@
+--TEST--
+DOMDocument::saveXML(): XML_SAVE_NO_DECL
+--EXTENSIONS--
+dom
+--FILE--
+<?php
+$doc = new DOMDocument();
+$doc->loadXML('<root>é</root>');
+
+echo $doc->saveXML(options: 0);
+echo $doc->saveXML(options: LIBXML_NOXMLDECL);
+$doc->encoding = "BIG5";
+echo $doc->saveXML(options: LIBXML_NOXMLDECL);
+
+// Edge case
+$doc = new DOMDocument();
+var_dump($doc->saveXML(options: LIBXML_NOXMLDECL));
+?>
+--EXPECT--
+<?xml version="1.0"?>
+<root>&#xE9;</root>
+<root>&#xE9;</root>
+<root>&#233;</root>
+string(0) ""