[gupnp-av] Add XML helper function removing child element.

[Jens Georg <jensgeorg src gnome org>]

commit f6f5a2999c94c9718f56b5fb9854d39e95f66920
Author: Krzesimir Nowak <krnowak openismus com>
Date:   Fri Sep 7 15:08:22 2012 +0200

    Add XML helper function removing child element.
    
    Will be needed for unsetting independent properties.

 libgupnp-av/xml-util.c |   19 +++++++++++++++----
 libgupnp-av/xml-util.h |    4 ++++
 2 files changed, 19 insertions(+), 4 deletions(-)
---
diff --git a/libgupnp-av/xml-util.c b/libgupnp-av/xml-util.c
index 4d345b8..a2cfc16 100644
--- a/libgupnp-av/xml-util.c
+++ b/libgupnp-av/xml-util.c
@@ -65,9 +65,8 @@ xml_util_get_child_elements_by_name (xmlNode *node, const char *name)
        GList *children = NULL;
 
        for (node = node->children; node; node = node->next) {
-               if (node->name == NULL) {
+               if (node->name == NULL)
                        continue;
-               }
 
                if (strcmp (name, (char *) node->name) == 0) {
                        children = g_list_append (children, node);
@@ -229,12 +228,11 @@ xml_util_set_child (xmlNode    *parent_node,
         xmlChar *escaped;
 
         node = xml_util_get_element (parent_node, name, NULL);
-        if (node == NULL) {
+        if (node == NULL)
                 node = xmlNewChild (parent_node,
                                     namespace,
                                     (unsigned char *) name,
                                     NULL);
-        }
 
         escaped = xmlEncodeSpecialChars (doc, (const unsigned char *) value);
         xmlNodeSetContent (node, escaped);
@@ -243,6 +241,19 @@ xml_util_set_child (xmlNode    *parent_node,
         return node;
 }
 
+void
+xml_util_unset_child (xmlNode    *parent_node,
+                      const char *name)
+{
+        xmlNode *node;
+
+        node = xml_util_get_element (parent_node, name, NULL);
+        if (node != NULL) {
+                xmlUnlinkNode (node);
+                xmlFreeNode (node);
+        }
+}
+
 gboolean
 xml_util_verify_attribute_is_boolean (xmlNode    *node,
                                       const char *attribute_name)
diff --git a/libgupnp-av/xml-util.h b/libgupnp-av/xml-util.h
index 80d9b82..4d63dc7 100644
--- a/libgupnp-av/xml-util.h
+++ b/libgupnp-av/xml-util.h
@@ -88,6 +88,10 @@ xml_util_set_child                      (xmlNode    *parent_node,
                                          const char *name,
                                          const char *value);
 
+G_GNUC_INTERNAL void
+xml_util_unset_child                    (xmlNode    *parent_node,
+                                         const char *name);
+
 G_GNUC_INTERNAL gboolean
 xml_util_verify_attribute_is_boolean    (xmlNode    *node,
                                          const char *attribute_name);