[libxml2] Fix comparison with root node in xmlXPathCmpNodes

[Nick Wellnhofer <nwellnhof src gnome org>]

commit a005199330b86dada19d162cae15ef9bdcb6baa8
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Tue Jun 28 14:19:58 2016 +0200

    Fix comparison with root node in xmlXPathCmpNodes
    
    This change has already been made in xmlXPathCmpNodesExt but not in
    xmlXPathCmpNodes.

 xpath.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/xpath.c b/xpath.c
index 751665b..d992841 100644
--- a/xpath.c
+++ b/xpath.c
@@ -3342,13 +3342,13 @@ xmlXPathCmpNodes(xmlNodePtr node1, xmlNodePtr node2) {
      * compute depth to root
      */
     for (depth2 = 0, cur = node2;cur->parent != NULL;cur = cur->parent) {
-       if (cur == node1)
+       if (cur->parent == node1)
            return(1);
        depth2++;
     }
     root = cur;
     for (depth1 = 0, cur = node1;cur->parent != NULL;cur = cur->parent) {
-       if (cur == node2)
+       if (cur->parent == node2)
            return(-1);
        depth1++;
     }