patch 8.0.0649: when opening a help file the filetype is set several times commit https://github.com/vim/vim/commit/9049298f8d0bbc237b7c666c7ad6cdabe738e8fc Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jun 22 14:16:31 2017 +0200 patch 8.0.0649: when opening a help file the filetype is set several times Problem: When opening a help file the filetype is set several times. Solution: When setting the filetype to the same value from a modeline, don't trigger FileType autocommands. Don't set the filetype to "help" when it's already set correctly.

" Vim compiler file
" Compiler:     ATT dot
" Maintainer:	Marcos Macedo <bar4ka@bol.com.br>
" Last Change:	2004 May 16

if exists("current_compiler")
  finish
endif
let current_compiler = "dot"

if exists(":CompilerSet") != 2		" older Vim always used :setlocal
  command -nargs=* CompilerSet setlocal <args>
endif

CompilerSet makeprg=dot\ -T$*\ \"%:p\"\ -o\ \"%:p:r.$*\"