Handle libxml2 OOM more consistently

This is a continuation of commit c2a58ab, in which several OOM error
handling was converted to throwing an INVALID_STATE_ERR DOMException.
Some places were missed and they still returned false without an
exception, or threw a PHP_ERR DOMException.
Convert all of these to INVALID_STATE_ERR DOMExceptions. This also
reduces confusion of users going through documentation [1].

Unfortunately, not all node creations are checked for a NULL pointer.
Some places therefore will not do anything if an OOM occurs (well,
except crash).
On the one hand it's nice to handle these OOM cases.
On the other hand, this adds some complexity and it's very unlikely to
happen in the real world. But then again, "unlikely" situations have
caused trouble before. Ideally all cases should be checked.

[1] php/doc-en#1741

Author: ndossche

UPGRADING

@@ -53,6 +53,9 @@ PHP 8.3 UPGRADE NOTES
   . Using the DOMParentNode and DOMChildNode methods without a document now works
     instead of throwing a HIERARCHY_REQUEST_ERR DOMException. This is in line with
     the behaviour spec demands.
+  . Some DOM methods previously returned false or a PHP_ERR DOMException if a new
+    node could not be allocated.
+    They consistently throw an INVALID_STATE_ERR DOMException now.
 
 - FFI:
   . C functions that have a return type of void now return null instead of

ext/dom/document.c

@@ -846,7 +846,12 @@ PHP_METHOD(DOMDocument, createElementNS)
 	if (errorcode == 0) {
 		if (xmlValidateName((xmlChar *) localname, 0) == 0) {
 			nodep = xmlNewDocNode(docp, NULL, (xmlChar *) localname, (xmlChar *) value);
-			if (nodep != NULL && uri != NULL) {
+			if (UNEXPECTED(nodep == NULL)) {
+				php_dom_throw_error(INVALID_STATE_ERR, /* strict */ true);
+				RETURN_THROWS();
+			}
+
+			if (uri != NULL) {
 				xmlNsPtr nsptr = xmlSearchNsByHref(nodep->doc, nodep, (xmlChar *) uri);
 				if (nsptr == NULL) {
 					nsptr = dom_get_ns(nodep, uri, &errorcode, prefix);
@@ -864,17 +869,11 @@ PHP_METHOD(DOMDocument, createElementNS)
 	}
 
 	if (errorcode != 0) {
-		if (nodep != NULL) {
-			xmlFreeNode(nodep);
-		}
+		xmlFreeNode(nodep);
 		php_dom_throw_error(errorcode, dom_get_strict_error(intern->document));
 		RETURN_FALSE;
 	}
 
-	if (nodep == NULL) {
-		RETURN_FALSE;
-	}
-
 	DOM_RET_OBJ(nodep, &ret, intern);
 }
 /* }}} end dom_document_create_element_ns */
@@ -908,7 +907,12 @@ PHP_METHOD(DOMDocument, createAttributeNS)
 		if (errorcode == 0) {
 			if (xmlValidateName((xmlChar *) localname, 0) == 0) {
 				nodep = (xmlNodePtr) xmlNewDocProp(docp, (xmlChar *) localname, NULL);
-				if (nodep != NULL && uri_len > 0) {
+				if (UNEXPECTED(nodep == NULL)) {
+					php_dom_throw_error(INVALID_STATE_ERR, /* strict */ true);
+					RETURN_THROWS();
+				}
+
+				if (uri_len > 0) {
 					nsptr = xmlSearchNsByHref(nodep->doc, root, (xmlChar *) uri);
 					if (nsptr == NULL) {
 						nsptr = dom_get_ns(root, uri, &errorcode, prefix);
@@ -930,17 +934,11 @@ PHP_METHOD(DOMDocument, createAttributeNS)
 	}
 
 	if (errorcode != 0) {
-		if (nodep != NULL) {
-			xmlFreeProp((xmlAttrPtr) nodep);
-		}
+		xmlFreeProp((xmlAttrPtr) nodep);
 		php_dom_throw_error(errorcode, dom_get_strict_error(intern->document));
 		RETURN_FALSE;
 	}
 
-	if (nodep == NULL) {
-		RETURN_FALSE;
-	}
-
 	DOM_RET_OBJ(nodep, &ret, intern);
 }
 /* }}} end dom_document_create_attribute_ns */

ext/dom/domimplementation.c

@@ -172,7 +172,8 @@ PHP_METHOD(DOMImplementation, createDocument)
 		if (localname != NULL) {
 			xmlFree(localname);
 		}
-		RETURN_FALSE;
+		php_dom_throw_error(INVALID_STATE_ERR, /* strict */ true);
+		RETURN_THROWS();
 	}
 
 	if (doctype != NULL) {
@@ -195,8 +196,7 @@ PHP_METHOD(DOMImplementation, createDocument)
 			}
 			xmlFreeDoc(docp);
 			xmlFree(localname);
-			/* Need some better type of error here */
-			php_dom_throw_error(PHP_ERR, 1);
+			php_dom_throw_error(INVALID_STATE_ERR, /* strict */ true);
 			RETURN_THROWS();
 		}
 

ext/dom/node.c

@@ -681,7 +681,8 @@ int dom_node_prefix_write(dom_object *obj, zval *newval)
 					(nodep->type == XML_ATTRIBUTE_NODE && zend_string_equals_literal(prefix_str, "xmlns") &&
 					 strcmp(strURI, (char *) DOM_XMLNS_NAMESPACE)) ||
 					(nodep->type == XML_ATTRIBUTE_NODE && !strcmp((char *) nodep->name, "xmlns"))) {
-					ns = NULL;
+					php_dom_throw_error(NAMESPACE_ERR, dom_get_strict_error(obj->document));
+					return FAILURE;
 				} else {
 					curns = nsnode->nsDef;
 					while (curns != NULL) {
@@ -693,14 +694,13 @@ int dom_node_prefix_write(dom_object *obj, zval *newval)
 					}
 					if (ns == NULL) {
 						ns = xmlNewNs(nsnode, nodep->ns->href, (xmlChar *)prefix);
+						if (UNEXPECTED(ns == NULL)) {
+							php_dom_throw_error(INVALID_STATE_ERR, /* strict */ true);
+							return FAILURE;
+						}
 					}
 				}
 
-				if (ns == NULL) {
-					php_dom_throw_error(NAMESPACE_ERR, dom_get_strict_error(obj->document));
-					return FAILURE;
-				}
-
 				xmlSetNs(nodep, ns);
 			}
 			break;

ext/dom/text.c

@@ -152,8 +152,8 @@ PHP_METHOD(DOMText, splitText)
 	xmlFree(second);
 
 	if (nnode == NULL) {
-		/* TODO Add warning? */
-		RETURN_FALSE;
+		php_dom_throw_error(INVALID_STATE_ERR, /* strict */ true);
+		RETURN_THROWS();
 	}
 
 	if (node->parent != NULL) {