Fix #474 - Load ftdetect files in filetypedetect augroup

plug.vim

@@ -222,7 +222,9 @@ function! plug#end()
     if has_key(plug, 'for')
       let types = s:to_a(plug.for)
       if !empty(types)
+        augroup filetypedetect
         call s:source(s:rtp(plug), 'ftdetect/**/*.vim', 'after/ftdetect/**/*.vim')
+        augroup END
       endif
       for type in types
         call s:assoc(lod.ft, type, name)

test/regressions.vader

@@ -286,3 +286,19 @@ Execute (#350: Ruby installer failed to unshallow tagged plugin on update):
   PlugUpdate
   Assert !filereadable(g:plugs['vim-easy-align'].dir.'/.git/shallow')
   q
+
+**********************************************************************
+Execute (#474: Load ftdetect files in filetypedetect augroup):
+  call plug#begin('/tmp/plugged')
+  Plug 'junegunn/rust.vim', { 'for': 'rust', 'commit': '115d321d383eb96d438466c56cc871fcc1bd0faa' }
+  call plug#end()
+  PlugInstall
+  q
+
+  tabnew /tmp/any.rs
+  AssertEqual 'rust', &filetype
+  Log &filetype
+  filetype detect
+  AssertEqual 'rust', &filetype
+  Log &filetype
+  bd

test/run

@@ -27,6 +27,7 @@ clone_repos() (
   done
   clone https://github.com/vim-scripts/beauty256.git vim-scripts/beauty256 &
   clone https://github.com/junegunn/fzf.git fzf &
+  clone https://github.com/rust-lang/rust.vim.git junegunn/rust.vim &
   clone https://github.com/yous/subsubmodule.git yous/subsubmodule && \
     (cd yous/subsubmodule && git submodule update --init --recursive &) &
   wait