util: xml: Introduce virXMLNodeGetSubelement

Introduce a simple helper fetching a sub-element node by name. This is
meant as a simple replacement for either open-coded versions of this or
use of XPath for this trivial lookup.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/libvirt_private.syms

@@ -3671,6 +3671,7 @@ virXMLFormatElementInternal;
 virXMLFormatMetadata;
 virXMLNewNode;
 virXMLNodeContentString;
+virXMLNodeGetSubelement;
 virXMLNodeNameEqual;
 virXMLNodeSanitizeNamespaces;
 virXMLNodeToString;

src/util/virxml.c

@@ -849,6 +849,29 @@ virXPathBoolean(const char *xpath,
 }
 
 
+/**
+ * virXMLNodeGetSubelement:
+ * @node: node to get subelement of
+ * @name: name of subelement to fetch
+ *
+ * Find and return a sub-element node of @node named @name.
+ */
+xmlNodePtr
+virXMLNodeGetSubelement(xmlNodePtr node,
+                        const char *name)
+{
+    xmlNodePtr n;
+
+    for (n = node->children; n; n = n->next) {
+        if (n->type == XML_ELEMENT_NODE &&
+            virXMLNodeNameEqual(n, name))
+            return n;
+    }
+
+    return NULL;
+}
+
+
 /**
  * virXPathNode:
  * @xpath: the XPath string to evaluate

src/util/virxml.h

@@ -72,6 +72,11 @@ int
 virXPathLongLong(const char *xpath,
                  xmlXPathContextPtr ctxt,
                  long long *value);
+
+xmlNodePtr
+virXMLNodeGetSubelement(xmlNodePtr node,
+                        const char *name);
+
 xmlNodePtr
 virXPathNode(const char *xpath,
              xmlXPathContextPtr ctxt);