[libxml2] Fix a change of semantic on XPath preceding and following axis

[Daniel Veillard <veillard src gnome org>]

commit ea90b894146030c214a7df6d8375310174f134b9
Author: Daniel Veillard <veillard redhat com>
Date:   Fri Oct 22 15:50:50 2010 +0200

    Fix a change of semantic on XPath preceding and following axis
    
    This was introduced in the prevous fix, while preceding-sibling and
    following sibling axis are empty for attributes and namespaces,
    preceding and following axis should still work based on the parent
    element. However the parent element is not available for a namespace
    node, so we keep the axis empty in that case.

 xpath.c |   33 +++++++++++++++++----------------
 1 files changed, 17 insertions(+), 16 deletions(-)
---
diff --git a/xpath.c b/xpath.c
index 9d47618..3352a5e 100644
--- a/xpath.c
+++ b/xpath.c
@@ -8106,17 +8106,17 @@ xmlXPathNextPrecedingSibling(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
 xmlNodePtr
 xmlXPathNextFollowing(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
     if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
-    if ((ctxt->context->node->type == XML_ATTRIBUTE_NODE) ||
-	(ctxt->context->node->type == XML_NAMESPACE_DECL))
-	return(NULL);
-    if (cur != NULL) {
-        if ((cur->type == XML_ATTRIBUTE_NODE) ||
-            (cur->type == XML_NAMESPACE_DECL))
+    if ((cur != NULL) && (cur->type  != XML_ATTRIBUTE_NODE) &&
+        (cur->type != XML_NAMESPACE_DECL) && (cur->children != NULL))
+        return(cur->children);
+
+    if (cur == NULL) {
+        cur = ctxt->context->node;
+        if (cur->type == XML_NAMESPACE_DECL)
             return(NULL);
-        if (cur->children != NULL)
-            return cur->children ;
+        if (cur->type == XML_ATTRIBUTE_NODE)
+            cur = cur->parent;
     }
-    if (cur == NULL) cur = ctxt->context->node;
     if (cur == NULL) return(NULL) ; /* ERROR */
     if (cur->next != NULL) return(cur->next) ;
     do {
@@ -8170,11 +8170,13 @@ xmlNodePtr
 xmlXPathNextPreceding(xmlXPathParserContextPtr ctxt, xmlNodePtr cur)
 {
     if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
-    if ((ctxt->context->node->type == XML_ATTRIBUTE_NODE) ||
-	(ctxt->context->node->type == XML_NAMESPACE_DECL))
-	return(NULL);
-    if (cur == NULL)
+    if (cur == NULL) {
         cur = ctxt->context->node;
+        if (cur->type == XML_NAMESPACE_DECL)
+            return(NULL);
+        if (cur->type == XML_ATTRIBUTE_NODE)
+            return(cur->parent);
+    }
     if (cur == NULL)
 	return (NULL);
     if ((cur->prev != NULL) && (cur->prev->type == XML_DTD_NODE))
@@ -8214,13 +8216,12 @@ xmlXPathNextPrecedingInternal(xmlXPathParserContextPtr ctxt,
                               xmlNodePtr cur)
 {
     if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
-    if ((ctxt->context->node->type == XML_ATTRIBUTE_NODE) ||
-	(ctxt->context->node->type == XML_NAMESPACE_DECL))
-	return(NULL);
     if (cur == NULL) {
         cur = ctxt->context->node;
         if (cur == NULL)
             return (NULL);
+        if (cur->type == XML_NAMESPACE_DECL)
+            return (NULL);
         ctxt->ancestor = cur->parent;
     }
     if ((cur->prev != NULL) && (cur->prev->type == XML_DTD_NODE))