When opening new files, a buffer number is skipped

[nalzok]

Problem description

Suppose I'm editing a single file in buffer 1. When I open a new file with :CtrlP, instead of opening it in buffer 2, ctrlp opens buffer 3. If I try to open another file with :CtrlP now, buffer 4 would be opened.

That is to say, buffer 2 is skipped for some reason.

Here is the output of :buffers:

:buffers
  1      "main.c"                       line 5
  3 #    "tags"                         line 20
  4 %a   "Makefile"                     line 10

However, buffer 2 is created as expected when I manually open files with :edit, so I think it might be a bug of ctrlp. Also, if I start vim without specifying any file, buffer 1, 3, 4, 5, ... would be created sequentially.

After some research, I think the function s:PrtExit() is very fishy. I guess it's used to disable autocommands which would close the buffers, since if I comment out these lines, buffer 3, 4, 5, ... would be created sequentially, skipping both buffer 1 and 2:

fu! s:PrtExit()
    let bw = bufwinnr('%')
    exe bufwinnr(s:bufnr).'winc w'
    if bufnr('%') == s:bufnr && bufname('%') == 'ControlP'
        " noa cal s:Close()
        " noa winc p
    els
        " exe bw.'winc w'
    en
endf

Did you miss anything there?

Version information

$ uname -a
Darwin 192.168.0.111 16.7.0 Darwin Kernel Version 16.7.0: Thu Jun 15 17:36:27 PDT 2017; root:xnu-3789.70.16~2/RELEASE_X86_64 x86_64
$ vim --version
VIM - Vi IMproved 8.0 (2016 Sep 12, compiled Aug 26 2017 15:16:30)
MacOS X (unix) version
Included patches: 1-997
Compiled by Homebrew
Huge version without GUI.  Features included (+) or not (-):
+acl             +file_in_path    +mouse_sgr       +tag_old_static
+arabic          +find_in_path    -mouse_sysmouse  -tag_any_white
+autocmd         +float           +mouse_urxvt     -tcl
-balloon_eval    +folding         +mouse_xterm     +termguicolors
-browse          -footer          +multi_byte      +terminal
++builtin_terms  +fork()          +multi_lang      +terminfo
+byte_offset     -gettext         -mzscheme        +termresponse
+channel         -hangul_input    +netbeans_intg   +textobjects
+cindent         +iconv           +num64           +timers
-clientserver    +insert_expand   +packages        +title
+clipboard       +job             +path_extra      -toolbar
+cmdline_compl   +jumplist        +perl            +user_commands
+cmdline_hist    +keymap          +persistent_undo +vertsplit
+cmdline_info    +lambda          +postscript      +virtualedit
+comments        +langmap         +printer         +visual
+conceal         +libcall         +profile         +visualextra
+cryptv          +linebreak       +python          +viminfo
+cscope          +lispindent      -python3         +vreplace
+cursorbind      +listcmds        +quickfix        +wildignore
+cursorshape     +localmap        +reltime         +wildmenu
+dialog_con      -lua             +rightleft       +windows
+diff            +menu            +ruby            +writebackup
+digraphs        +mksession       +scrollbind      -X11
-dnd             +modify_fname    +signs           -xfontset
-ebcdic          +mouse           +smartindent     -xim
+emacs_tags      -mouseshape      +startuptime     -xpm
+eval            +mouse_dec       +statusline      -xsmp
+ex_extra        -mouse_gpm       -sun_workshop    -xterm_clipboard
+extra_search    -mouse_jsbterm   +syntax          -xterm_save
+farsi           +mouse_netterm   +tag_binary
   system vimrc file: "$VIM/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
       defaults file: "$VIMRUNTIME/defaults.vim"
  fall-back for $VIM: "/usr/local/share/vim"
Compilation: clang -c -I. -Iproto -DHAVE_CONFIG_H   -DMACOS_X_UNIX  -g -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1
Linking: clang   -L. -fstack-protector -L/usr/local/lib -L/usr/local/opt/libyaml/lib -L/usr/local/opt/openssl/lib -L/usr/local/opt/readline/lib  -L/usr/local/lib -o vim        -lncurses -liconv -framework Cocoa   -mmacosx-version-min=10.12 -fstack-protector-strong -L/usr/local/lib  -L/usr/local/Cellar/perl/5.26.0/lib/perl5/5.26.0/darwin-thread-multi-2level/CORE -lperl -lm -lutil -lc -F/usr/local/opt/python/Frameworks -framework Python   -lruby.2.4.1 -lobjc

dotfile

" An example for a vimrc file.
"
" Maintainer:   Bram Moolenaar <Bram@vim.org>
" Last change:  2008 Dec 17
"
" To use it, copy it to
"     for Unix and OS/2:  ~/.vimrc
"         for Amiga:  s:.vimrc
"  for MS-DOS and Win32:  $VIM\_vimrc
"       for OpenVMS:  sys$login:.vimrc

" When started as "evim", evim.vim will already have done these settings.
if v:progname =~? "evim"
  finish
endif

" Use Vim settings, rather than Vi settings (much better!).
" This must be first, because it changes other options as a side effect.
set nocompatible

" vim-plug, Minimalist Vim Plugin Manager
" https://github.com/junegunn/vim-plug
" You'll need to call `:PlugInstall` to install the plugins
call plug#begin('~/.vim/plugged')
Plug 'tpope/vim-sensible'           " https://github.com/tpope/vim-sensible
Plug 'ctrlpvim/ctrlp.vim'           " https://github.com/ctrlpvim/ctrlp.vim
Plug 'vim-airline/vim-airline'      " https://github.com/vim-airline/vim-airline
Plug 'bling/vim-bufferline'         " https://github.com/bling/vim-bufferline
Plug 'xolox/vim-misc'               " https://github.com/xolox/vim-misc
Plug 'xolox/vim-easytags'           " https://github.com/xolox/vim-easytags
Plug 'majutsushi/tagbar'            " https://github.com/majutsushi/tagbar
Plug 'skywind3000/asyncrun.vim'     " https://github.com/skywind3000/asyncrun.vim
call plug#end()

" allow backspacing over everything in insert mode
set backspace=indent,eol,start

if has("vms")
  set nobackup      " do not keep a backup file, use versions instead
else
  set backup        " keep a backup file
endif

set history=50      " keep 50 lines of command line history
set ruler           " show the cursor position all the time
set showcmd         " display incomplete commands
set incsearch       " do incremental searching

" For Win32 GUI: remove 't' flag from 'guioptions': no tearoff menu entries
" let &guioptions = substitute(&guioptions, "t", "", "g")

" Don't use Ex mode, use Q for formatting
map Q gq

" CTRL-U in insert mode deletes a lot.  Use CTRL-G u to first break undo,
" so that you can undo CTRL-U after inserting a line break.
inoremap <C-U> <C-G>u<C-U>

" In many terminal emulators the mouse works just fine, thus enable it.
if has('mouse')
  set mouse=a
endif

" Switch syntax highlighting on, when the terminal has colors
" Also switch on highlighting the last used search pattern.
if &t_Co > 2 || has("gui_running")
  syntax on
  set hlsearch
endif

" Only do this part when compiled with support for autocommands.
if has("autocmd")

  " Enable file type detection.
  " Use the default filetype settings, so that mail gets 'tw' set to 72,
  " 'cindent' is on in C files, etc.
  " Also load indent files, to automatically do language-dependent indenting.
  filetype plugin indent on

  " Put these in an autocmd group, so that we can delete them easily.
  augroup vimrcEx
  au!

  " For all text files set 'textwidth' to 78 characters.
  autocmd FileType text setlocal textwidth=78

  " When editing a file, always jump to the last known cursor position.
  " Don't do it when the position is invalid or when inside an event handler
  " (happens when dropping a file on gvim).
  " Also don't do it when the mark is in the first line, that is the default
  " position when opening a file.
  autocmd BufReadPost *
    \ if line("'\"") > 1 && line("'\"") <= line("$") |
    \   exe "normal! g`\"" |
    \ endif

  augroup END

else

  set autoindent        " always set autoindenting on

endif " has("autocmd")

" Convenient command to see the difference between the current buffer and the
" file it was loaded from, thus the changes you made.
" Only define it when not defined already.
if !exists(":DiffOrig")
  command DiffOrig vert new | set bt=nofile | r # | 0d_ | diffthis
          \ | wincmd p | diffthis
endif

" Molokai colorscheme
syntax enable
let g:rehash256 = 1
colorscheme molokai

" Define tab as 4 spaces
" Taken from http://stackoverflow.com/questions/1878974/redefine-tab-as-4-spaces
set tabstop=4       " The width of a TAB is set to 4.
                    " Still it is a \t. It is just that
                    " Vim will interpret it to be having
                    " a width of 4.
set shiftwidth=4    " Indents will have a width of 4
set softtabstop=4   " Sets the number of columns for a TAB
set expandtab       " Expand TABs to spaces

" Set a 80-column indication line
" https://stackoverflow.com/a/3305790/5399734
highlight OverLength ctermbg=darkred ctermfg=white guibg=#FFD9D9 guifg=white
match OverLength /\%>79v.\+/

" Highlight the current line
set cursorline

" Airline
" https://github.com/vim-airline/vim-airline
let g:airline_powerline_fonts = 1
let g:airline#extensions#tagbar#enabled = 0

" Bufferline
" https://github.com/bling/vim-bufferline
let g:bufferline_echo = 0
autocmd VimEnter *
\ let &statusline='%{bufferline#refresh_status()}'
  \ .bufferline#get_status_string()
let g:bufferline_rotate = 1
let g:bufferline_fixed_index = 0
let g:bufferline_solo_highlight = 0

" Tagbar
" https://github.com/majutsushi/tagbar
nmap <F8> :TagbarToggle<CR>
let g:tagbar_autoclose = 1
let g:tagbat_autofocus = 1
let g:tagbar_compact = 1
let g:tagbar_autoshowtag = 1
" Speed up tagbar updating
" https://github.com/majutsushi/tagbar/issues/413
set updatetime=500

" vim-easytags
" https://peterodding.com/code/vim/easytags/
let g:easytags_async = 1
set tags=./tags;    " this `;` means recurses upwards
set cpoptions+=d
let g:easytags_dynamic_files = 2
let g:easytags_always_enabled = 1
let g:easytags_auto_highlight = 0
let g:easytags_include_members = 1
let g:easytags_resolve_links = 1

augroup vimrc
    " Auto rebuild C/C++ project when source file is updated, asynchronously
    autocmd BufWritePost *.c,*.cpp,*.h
      \   let dir=expand('<amatch>:p:h')
      \ | if filereadable(dir.'/Makefile') || filereadable(dir.'/makefile')
      \ |   execute 'AsyncRun -cwd=<root> make'
      \ | endif
    " Auto toggle the quickfix window
    autocmd User AsyncRunStop
      \   if g:asyncrun_status=='failure'
      \ |   execute('call asyncrun#quickfix_toggle(8, 1)')
      \ | else
      \ |   execute('call asyncrun#quickfix_toggle(8, 0)')
      \ | endif
augroup END
let g:airline_section_warning = airline#section#create_right(['%{g:asyncrun_status}'])

[mattn]

This is workaround for https://github.com/ctrlpvim/ctrlp.vim/issues/253

[mattn]

closed by https://github.com/ctrlpvim/ctrlp.vim/pull/259