Utils: add function to extract/create node in lists

* lasso_extract_gtype_from_list_or_new will help for method with create
   or extend nodes in lists.

lasso/saml-2.0/Makefile.am

@@ -19,6 +19,9 @@ liblasso_saml_20_la_SOURCES = \
 	logout.c \
 	name_id_management.c \
 	server.c \
+	saml2_conditions_addons.c \
+	saml2_assertion_addons.c \
+	samlp2_authn_request_addons.c \
 	saml2_helper.c
 
 liblassoinclude_HEADERS = \
@@ -27,6 +30,9 @@ liblassoinclude_HEADERS = \
 	profile.h \
 	name_id_management.h \
 	provider.h \
+	saml2_conditions_addons.h \
+	saml2_assertion_addons.h \
+	samlp2_authn_request_addons.h \
 	saml2_helper.h
 
 lasso_private_h_sources = \

lasso/utils.c

@@ -127,10 +127,37 @@ lasso_extract_gtype_from_list(GType type, GList *list)
 {
 	GList *needle;
 
-
 	needle = g_list_find_custom(list, (gconstpointer)type, (GCompareFunc)lasso_gobject_is_of_type);
 	if (needle) {
 		return needle->data;
 	}
 	return NULL;
 }
+
+/**
+ * lasso_extract_gtype_from_list_or_new:
+ * @type: a #GType
+ * @list: a pointer to a #GList pointer variable
+ * @create: whether to look up an object whose #GType is type, or to just create it.
+ * 
+ * If create is TRUE, add a new object of type @type to @list and return it.
+ * Otherwise try to look up an object of type @type, and if none is found add a new one and return
+ * it.
+ *
+ * Return value: a #GObject of type @type.
+ */
+GObject *
+lasso_extract_gtype_from_list_or_new(GType type, GList **list, gboolean create)
+{
+	GObject *result = NULL;
+	g_assert (list);
+
+	if (! create) {
+		result = lasso_extract_gtype_from_list(type, *list);
+	}
+	if (result == NULL) {
+		result = g_object_new(type, NULL);
+		lasso_list_add_new_gobject(*list, result);
+	}
+	return result;
+}

lasso/utils.h

@@ -599,9 +599,13 @@ lasso_is_empty_string(const char *str) {
 
 /* Get a printable extract for error messages */
 char* lasso_safe_prefix_string(const char *str, gsize length);
+
 int lasso_gobject_is_of_type(GObject *a, GType b);
+
 GObject *lasso_extract_gtype_from_list(GType type, GList *list);
 
+GObject * lasso_extract_gtype_from_list_or_new(GType type, GList **list, gboolean create);
+
 /* Get first node of this type in a list */
 /* ex: lasso_extract_node (LassoNode, LASSO_TYPE_NODE, list) */
 #define lasso_extract_gobject_from_list(type, gobjecttype, list) \