/**
- * Create an (empty) temporary file on disk.
+ * Create an (empty) temporary file on disk. If the given name is not
+ * an absolute path, the current 'TMPDIR' will be prepended. In any case,
+ * 6 random characters will be appended to the name to create a unique
+ * filename.
*
* @param t component to use for the name;
* does NOT contain "XXXXXX" or "/tmp/".
*
* @param cls closure
* @param di argument to pass to "GNUNET_DISK_directory_iterator_next" to
- * get called on the next entry (or finish cleanly)
+ * get called on the next entry (or finish cleanly);
+ * NULL on error (will be the last call in that case)
* @param filename complete filename (absolute path)
* @param dirname directory name (absolute path)
*/