commit 39cb72740326645358bbf238f4940fbb77adc6ff
Author: Olli Pottonen <olli pottonen iki fi>
Date:   Sat Jul 11 09:02:48 2015 +1000

    Fix order of distinct documents.
    
    In xmlXPathCmpNodesExt, fix case where two nodes are from distinct
    documents.

diff --git a/xpath.c b/xpath.c
index e9f5bf9..441c14d 100644
--- a/xpath.c
+++ b/xpath.c
@@ -152,7 +152,7 @@ xmlXPathCmpNodesExt(xmlNodePtr node1, xmlNodePtr node2) {
     int depth1, depth2;
     int misc = 0, precedence1 = 0, precedence2 = 0;
     xmlNodePtr miscNode1 = NULL, miscNode2 = NULL;
-    xmlNodePtr cur, root;
+    xmlNodePtr cur, root1, root2;
     long l1, l2;
 
     if ((node1 == NULL) || (node2 == NULL))
@@ -365,17 +365,18 @@ turtle_comparison:
 	if (cur == node1)
 	    return(1);
 	depth2++;
+	root1 = cur;
     }
-    root = cur;
     for (depth1 = 0, cur = node1; cur != NULL; cur = cur->parent) {
 	if (cur == node2)
 	    return(-1);
 	depth1++;
+	root2 = cur;
     }
     /*
      * Distinct document (or distinct entities :-( ) case.
      */
-    if (root != cur) {
+    if (root1 != root2) {
 	return(-2);
     }
     /*