All this patch does is to remove the directory name from the
=attachment:file.ext= -- given that the path is calculated by org-attach
--, and use the group 1 of the match string (as well as updating the use
of an obsolete variable), which corresponds to the actual link portion,
leaving the description unchanged.

Cordially,

-- 
João Pedro de A. Paula
IT undergraduate at Universidade Federal do Rio Grande do Norte (UFRN)