Filetype custom options are not used except for the first filetype.

[notomo]

Problems summary

deoplete#custom#option('sources', {...}) are not used except for the first filetype.

Expected

Current buffer filetype options are used.

Environment Information

• deoplete version (SHA1):
  6688027

• OS:
  CentOS 7.3

• neovim/Vim :version output:

NVIM v0.3.2-930-g3348eea42
Build type: RelWithDebInfo
LuaJIT 2.0.5
Compilation: /usr/bin/gcc-5 -Wconversion -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1 -O2 -g -DMIN_LOG_LEVEL=3 -Og -g -Wall -Wextra -pedantic -Wno-unused-parameter -Wstrict-prototypes -std=gnu99 -Wvla -fstack-protector-strong -fdiagnostics-color=auto -Wno-array-bounds -DINCLUDE_GENERATED_DECLARATIONS -D_GNU_SOURCE -DNVIM_MSGPACK_HAS_FLOAT32 -DNVIM_UNIBI_HAS_VAR_FROM -I/home/travis/build/neovim/bot-ci/build/neovim/build/config -I/home/travis/build/neovim/bot-ci/build/neovim/src -I/home/travis/build/neovim/bot-ci/build/neovim/.deps/usr/include -I/usr/include -I/home/travis/build/neovim/bot-ci/build/neovim/build/src/nvim/auto -I/home/travis/build/neovim/bot-ci/build/neovim/build/include
Compiled by travis@travis-job-8b9daf44-ab8f-4824-b3fd-9b9427295f41

Features: +acl +iconv +jemalloc +tui 
See ":help feature-compile"

   system vimrc file: "$VIM/sysinit.vim"
  fall-back for $VIM: "/home/travis/build/neovim/bot-ci/build/neovim/build/nvim.AppDir/usr/share/nvim"

Run :checkhealth for more info

• :checkhealth or :CheckHealth result(neovim only):

health#nvim#check
========================================================================
## Configuration
  - OK: no issues found

## Performance
  - OK: Build type: RelWithDebInfo

## Remote Plugins
  - OK: Up to date

## terminal
  - INFO: key_backspace (kbs) terminfo entry: key_backspace=^H
  - INFO: key_dc (kdch1) terminfo entry: key_dc=\E[3~
  - INFO: $SSH_TTY='/dev/pts/0'

health#provider#check
========================================================================
## Clipboard (optional)
  - OK: Clipboard tool found: xclip_in_vagrant

## Python 2 provider (optional)
  - INFO: Using: g:python_host_prog = "/usr/bin/python"
  - INFO: Executable: /usr/bin/python
  - INFO: Python version: 2.7.5
  - INFO: pynvim version: 0.3.1
  - OK: Latest pynvim is installed.

## Python 3 provider (optional)
  - INFO: Using: g:python3_host_prog = "/usr/bin/python3"
  - INFO: Executable: /usr/bin/python3
  - INFO: Python version: 3.6.5
  - INFO: pynvim version: 0.3.1
  - OK: Latest pynvim is installed.

## Ruby provider (optional)
  - WARNING: `ruby` and `gem` must be in $PATH.
    - ADVICE:
      - Install Ruby and verify that `ruby` and `gem` commands work.

## Node.js provider (optional)
  - INFO: Node.js: v9.11.2
  - INFO: Neovim node.js host: /usr/lib/node_modules/neovim/bin/cli.js
  - OK: Latest "neovim" npm/yarn package is installed: 4.2.1

health#deoplete#check
========================================================================
## deoplete.nvim
  - OK: exists("v:t_list") was successful
  - OK: has("timers") was successful
  - OK: has("python3") was successful
  - OK: Python3.5+ was successful
  - INFO: If you're still having problems, try the following commands:
    $ export NVIM_PYTHON_LOG_FILE=/tmp/log
    $ export NVIM_PYTHON_LOG_LEVEL=DEBUG
    $ nvim
    $ cat /tmp/log_{PID}
    and then create an issue on github

Provide a minimal init.vim/vimrc with less than 50 lines (Required!)

set runtimepath+=~/path/to/deoplete.nvim/
let g:deoplete#enable_at_startup = 1
call deoplete#custom#option('sources', {'vim' : 'around', 'python' : 'file'})

filetype plugin indent on

cd ~/path/to/deoplete.nvim
e rplugin/python3/deoplete/context.py
e autoload/deoplete.vim

How to reproduce the problem from neovim/Vim startup (Required!)

1. Input fun on autoload/deoplete.vim by insert mode. (function [B] are completed.)
2. Show the alternative buffer by <C-^>
3. Input ./ on rplugin/python3/deoplete/context.py by insert mode. (files are not completed.)