Hi!

I think a found a bug in org-babel-tangle-file. It closes an user-opened
buffer if called with a symlink that points to the same file. Please see
the attached patch, which fixes the problem for me.

chris

Emacs  : GNU Emacs 27.0.50 (build 5, x86_64-pc-linux-gnu, GTK+ Version 3.24.0)
 of 2018-10-06
Package: Org mode version 9.2.4 (9.2.4-3-g7bc6f8-elpaplus @ /home/stettberger/.emacs.d/elpa/org-plus-contrib-20190701/)