src/svgtiny_css.c: implement named_ancestor_node() select handler

diff --git a/src/svgtiny_css.c b/src/svgtiny_css.c
index f01c3b40df17ca066611aec5a3458c8d6d104bd2..97d6307d69c015ad8cf30ef58d1579c772ec9087 100644 (file)
--- a/src/svgtiny_css.c
+++ b/src/svgtiny_css.c
@@ -8,6 +8,8 @@ static css_error node_name(void *pw, void *node, css_qname *qname);
 static css_error node_classes(void *pw, void *node,
                lwc_string ***classes, uint32_t *n_classes);
 static css_error node_id(void *pw, void *node, lwc_string **id);
+static css_error named_ancestor_node(void *pw, void *node,
+               const css_qname *qname, void **ancestor);
 static css_error named_parent_node(void *pw, void *node,
                const css_qname *qname, void **parent);
 static css_error named_sibling_node(void *pw, void *node,
@@ -240,6 +242,40 @@ css_error node_id(void *pw, void *node, lwc_string **id)
 }
 
 
+/**
+ * Find the first ancestor of the given element having the given name
+ *
+ * This function thinly wraps dom_element_named_ancestor_node(), which
+ * performs exactly the search we want.
+ *
+ * \param pw        Pointer to the current SVG parser state
+ * \param node      Libdom SVG node whose ancestor we want
+ * \param qname     Name of the ancestor node to search for
+ * \param ancestor  Address at which to store the ancestor node pointer
+ *
+ * \return Always returns CSS_OK
+ *
+ * \post If a suitable element is found, a pointer to it will be
+ *       stored at the address pointed to by \a ancestor; otherwise,
+ *       NULL will be stored at the address pointed to by \a ancestor
+ */
+css_error named_ancestor_node(void *pw, void *node,
+               const css_qname *qname, void **ancestor)
+{
+       UNUSED(pw);
+
+       /* It's OK if node isn't an element, libdom checks for it. */
+       dom_element_named_ancestor_node((dom_element *)node,
+                       qname->name,
+                       (struct dom_element **)ancestor);
+
+       /* A comment in named_parent_node() explains why we unref
+        * this here. */
+       dom_node_unref(*ancestor);
+
+       return CSS_OK;
+}
+
 
 /**
  * Find the first parent of the given element having the given name