/* Add an extension, and all compressed versions thereof, to a GSList of extensions.  */
static GSList* add_extensions(GSList *extensions, const gchar *extension, const char **compressed_file_extensions)
/* Add an extension, and all compressed versions thereof, to a GSList of extensions.  */
static GSList* add_extensions(GSList *extensions, const gchar *extension, const char **compressed_file_extensions)
{
	const char **compressed_file_extensionp;
	extensions = g_slist_append(extensions, g_strdup(extension));
	for (compressed_file_extensionp = compressed_file_extensions;
	    *compressed_file_extensionp != NULL;
	    compressed_file_extensionp++) {
		extensions = g_slist_append(extensions,
		    g_strdup_printf("%s.%s", extension,
		      *compressed_file_extensionp));
	}
	return extensions;
}