The update to Vim 2:8.0.0197-4+deb9u2, which is a fix for DSA-4467-1, broke my OCaml development environment (merlin, ocp-indent, vim-ocaml). Every newly loaded buffer causes previously loaded buffers to lose their “filetype” setting. A temporary workaround is to apply <ESC>:set ft= followed by <ESC>:set ft=ocaml to affected buffers.
I just wanted to report that the described problem is specific to the debian package version 2:8.0.0197-4+deb9u2. It disappears after downgrading the package (not recommended) or using Vim’s current git/mercurial HEAD. The Vim version shipped with Debian testing (10 / Buster) doesn’t show the problem either.
Maybe this information is of worth for anyone here. Have a nice sunday.