libxml2/Fix-quadratic-runtime-in-xi-fallback-processing.patch
2021-10-21 17:51:09 +08:00

64 lines
1.9 KiB
Diff

From 27119ec33c9f6b9830efa1e0da0acfa353dfa55a Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Mon, 17 Aug 2020 00:05:19 +0200
Subject: [PATCH] Fix quadratic runtime in xi:fallback processing
Copying the tree would lead to runtime quadratic in nested fallback
depth, similar to naive string concatenation.
---
xinclude.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/xinclude.c b/xinclude.c
index e9d3af5..9a65ee5 100644
--- a/xinclude.c
+++ b/xinclude.c
@@ -2003,8 +2003,7 @@ xmlXIncludeLoadFallback(xmlXIncludeCtxtPtr ctxt, xmlNodePtr fallback, int nr) {
ret = -1;
xmlXIncludeFreeContext(newctxt);
- ctxt->incTab[nr]->inc = xmlDocCopyNodeList(ctxt->doc,
- fallback->children);
+ ctxt->incTab[nr]->inc = fallback->children;
} else {
ctxt->incTab[nr]->inc = NULL;
}
@@ -2268,12 +2267,6 @@ xmlXIncludeIncludeNode(xmlXIncludeCtxtPtr ctxt, int nr) {
* XInclude end one
*/
cur->type = XML_XINCLUDE_START;
- /* Remove fallback children */
- for (child = cur->children; child != NULL; child = next) {
- next = child->next;
- xmlUnlinkNode(child);
- xmlFreeNode(child);
- }
end = xmlNewDocNode(cur->doc, cur->ns, cur->name, NULL);
if (end == NULL) {
xmlXIncludeErr(ctxt, ctxt->incTab[nr]->ref,
@@ -2289,11 +2282,17 @@ xmlXIncludeIncludeNode(xmlXIncludeCtxtPtr ctxt, int nr) {
* Add the list of nodes
*/
while (list != NULL) {
- cur = list;
- list = list->next;
-
- xmlAddPrevSibling(end, cur);
+ next = list->next;
+ xmlAddPrevSibling(end, list);
+ list = next;
}
+
+ /* Remove fallback node */
+ for (child = cur->children; child != NULL; child = next) {
+ next = child->next;
+ xmlUnlinkNode(child);
+ xmlFreeNode(child);
+ }
}
--
1.8.3.1