Upgrade libxml2 and its portage dependencies

dev-libs/libxml2/files/libxml2-2.7.8-xpath-memory.patch

+From 0cbeb50ee03ce582a0c979c70d8fbf030e270c37 Mon Sep 17 00:00:00 2001
+From: Daniel Veillard <veillard@redhat.com>
+Date: Mon, 15 Nov 2010 11:06:29 +0000
+Subject: Fix a potential memory access error
+
+in case of a previus allocation error
+---
+diff --git a/xpath.c b/xpath.c
+index 4d6826d..81e33f6 100644
+--- a/xpath.c
++++ b/xpath.c
+@@ -3575,13 +3575,13 @@ xmlXPathNodeSetAdd(xmlNodeSetPtr cur, xmlNodePtr val) {
+     } else if (cur->nodeNr == cur->nodeMax) {
+         xmlNodePtr *temp;
+ 
+-        cur->nodeMax *= 2;
+-       temp = (xmlNodePtr *) xmlRealloc(cur->nodeTab, cur->nodeMax *
++       temp = (xmlNodePtr *) xmlRealloc(cur->nodeTab, cur->nodeMax * 2 *
+                                      sizeof(xmlNodePtr));
+        if (temp == NULL) {
+            xmlXPathErrMemory(NULL, "growing nodeset\n");
+            return;
+        }
++        cur->nodeMax *= 2;
+        cur->nodeTab = temp;
+     }
+     if (val->type == XML_NAMESPACE_DECL) {
+--
+cgit v0.8.3.1