Thank you for the bug report and patch!

The fix you provided has been applied to the development branch:
https://git.savannah.gnu.org/cgit/libtool.git/commit/?h=development&id=549b52175aa038fb8f5284e9b6dca957e391708b

-- 
Ileana Dumitrescu

GPG Public Key: FA26 CA78 4BE1 8892 7F22 B99F 6570 EA01 146F 7354