Update plug.vim to a recent version

.vim/autoload/plug.vim

@@ -96,7 +96,7 @@ let s:plug_src = 'https://github.com/junegunn/vim-plug.git'
 let s:plug_tab = get(s:, 'plug_tab', -1)
 let s:plug_buf = get(s:, 'plug_buf', -1)
 let s:mac_gui = has('gui_macvim') && has('gui_running')
-let s:is_win = has('win32') || has('win64')
+let s:is_win = has('win32')
 let s:nvim = has('nvim-0.2') || (has('nvim') && exists('*jobwait') && !s:is_win)
 let s:vim8 = has('patch-8.0.0039') && exists('*job_start')
 let s:me = resolve(expand('<sfile>:p'))
@@ -121,6 +121,9 @@ function! plug#begin(...)
   else
     return s:err('Unable to determine plug home. Try calling plug#begin() with a path argument.')
   endif
+  if fnamemodify(home, ':t') ==# 'plugin' && fnamemodify(home, ':h') ==# s:first_rtp
+    return s:err('Invalid plug home. '.home.' is a standard Vim runtime path and is not allowed.')
+  endif
 
   let g:plug_home = home
   let g:plugs = {}
@@ -190,6 +193,14 @@ function! s:ask_no_interrupt(...)
   endtry
 endfunction
 
+function! s:lazy(plug, opt)
+  return has_key(a:plug, a:opt) &&
+        \ (empty(s:to_a(a:plug[a:opt]))         ||
+        \  !isdirectory(a:plug.dir)             ||
+        \  len(s:glob(s:rtp(a:plug), 'plugin')) ||
+        \  len(s:glob(s:rtp(a:plug), 'after/plugin')))
+endfunction
+
 function! plug#end()
   if !exists('g:plugs')
     return s:err('Call plug#begin() first')
@@ -211,7 +222,7 @@ function! plug#end()
       continue
     endif
     let plug = g:plugs[name]
-    if get(s:loaded, name, 0) || !has_key(plug, 'on') && !has_key(plug, 'for')
+    if get(s:loaded, name, 0) || !s:lazy(plug, 'on') && !s:lazy(plug, 'for')
       let s:loaded[name] = 1
       continue
     endif
@@ -442,12 +453,13 @@ function! plug#load(...)
   if !exists('g:plugs')
     return s:err('plug#begin was not called')
   endif
-  let unknowns = filter(copy(a:000), '!has_key(g:plugs, v:val)')
+  let names = a:0 == 1 && type(a:1) == s:TYPE.list ? a:1 : a:000
+  let unknowns = filter(copy(names), '!has_key(g:plugs, v:val)')
   if !empty(unknowns)
     let s = len(unknowns) > 1 ? 's' : ''
     return s:err(printf('Unknown plugin%s: %s', s, join(unknowns, ', ')))
   end
-  let unloaded = filter(copy(a:000), '!get(s:loaded, v:val, 0)')
+  let unloaded = filter(copy(names), '!get(s:loaded, v:val, 0)')
   if !empty(unloaded)
     for name in unloaded
       call s:lod([name], ['ftdetect', 'after/ftdetect', 'plugin', 'after/plugin'])
@@ -601,7 +613,7 @@ function! plug#helptags()
     return s:err('plug#begin was not called')
   endif
   for spec in values(g:plugs)
-    let docd = join([spec.dir, 'doc'], '/')
+    let docd = join([s:rtp(spec), 'doc'], '/')
     if isdirectory(docd)
       silent! execute 'helptags' s:esc(docd)
     endif
@@ -759,6 +771,9 @@ function! s:prepare(...)
     execute 'silent! unmap <buffer>' k
   endfor
   setlocal buftype=nofile bufhidden=wipe nobuflisted nolist noswapfile nowrap cursorline modifiable nospell
+  if exists('+colorcolumn')
+    setlocal colorcolumn=
+  endif
   setf vim-plug
   if exists('g:syntax_on')
     call s:syntax()
@@ -778,8 +793,10 @@ function! s:assign_name()
 endfunction
 
 function! s:chsh(swap)
-  let prev = [&shell, &shellredir]
-  if !s:is_win && a:swap
+  let prev = [&shell, &shellcmdflag, &shellredir]
+  if s:is_win
+    set shell=cmd.exe shellcmdflag=/c shellredir=>%s\ 2>&1
+  elseif a:swap
     set shell=sh shellredir=>%s\ 2>&1
   endif
   return prev
@@ -787,15 +804,23 @@ endfunction
 
 function! s:bang(cmd, ...)
   try
-    let [sh, shrd] = s:chsh(a:0)
+    let [sh, shellcmdflag, shrd] = s:chsh(a:0)
     " FIXME: Escaping is incomplete. We could use shellescape with eval,
     "        but it won't work on Windows.
     let cmd = a:0 ? s:with_cd(a:cmd, a:1) : a:cmd
-    let g:_plug_bang = '!'.escape(cmd, '#!%')
+    if s:is_win
+      let batchfile = tempname().'.bat'
+      call writefile(["@echo off\r", cmd . "\r"], batchfile)
+      let cmd = batchfile
+    endif
+    let g:_plug_bang = (s:is_win && has('gui_running') ? 'silent ' : '').'!'.escape(cmd, '#!%')
     execute "normal! :execute g:_plug_bang\<cr>\<cr>"
   finally
     unlet g:_plug_bang
-    let [&shell, &shellredir] = [sh, shrd]
+    let [&shell, &shellcmdflag, &shellredir] = [sh, shellcmdflag, shrd]
+    if s:is_win
+      call delete(batchfile)
+    endif
   endtry
   return v:shell_error ? 'Exit status: ' . v:shell_error : ''
 endfunction
@@ -894,7 +919,7 @@ function! s:finish(pull)
     call add(msgs, "Press 'R' to retry.")
   endif
   if a:pull && len(s:update.new) < len(filter(getline(5, '$'),
-                \ "v:val =~ '^- ' && stridx(v:val, 'Already up-to-date') < 0"))
+                \ "v:val =~ '^- ' && v:val !~# 'Already up.to.date'"))
     call add(msgs, "Press 'D' to see the updated changes.")
   endif
   echo join(msgs, ' ')
@@ -994,6 +1019,8 @@ function! s:update_impl(pull, force, args) abort
     let s:clone_opt .= ' -c core.eol=lf -c core.autocrlf=input'
   endif
 
+  let s:submodule_opt = s:git_version_requirement(2, 8) ? ' --jobs='.threads : ''
+
   " Python version requirement (>= 2.7)
   if python && !has('python3') && !ruby && !use_job && s:update.threads > 1
     redir => pyv
@@ -1085,7 +1112,7 @@ function! s:update_finish()
       if !v:shell_error && filereadable(spec.dir.'/.gitmodules') &&
             \ (s:update.force || has_key(s:update.new, name) || s:is_updated(spec.dir))
         call s:log4(name, 'Updating submodules. This may take a while.')
-        let out .= s:bang('git submodule update --init --recursive 2>&1', spec.dir)
+        let out .= s:bang('git submodule update --init --recursive'.s:submodule_opt.' 2>&1', spec.dir)
       endif
       let msg = s:format_message(v:shell_error ? 'x': '-', name, out)
       if v:shell_error
@@ -1177,10 +1204,15 @@ endfunction
 
 function! s:spawn(name, cmd, opts)
   let job = { 'name': a:name, 'running': 1, 'error': 0, 'lines': [''],
+            \ 'batchfile': (s:is_win && (s:nvim || s:vim8)) ? tempname().'.bat' : '',
             \ 'new': get(a:opts, 'new', 0) }
   let s:jobs[a:name] = job
-  let argv = add(s:is_win ? ['cmd', '/c'] : ['sh', '-c'],
-               \ has_key(a:opts, 'dir') ? s:with_cd(a:cmd, a:opts.dir) : a:cmd)
+  let cmd = has_key(a:opts, 'dir') ? s:with_cd(a:cmd, a:opts.dir) : a:cmd
+  if !empty(job.batchfile)
+    call writefile(["@echo off\r", cmd . "\r"], job.batchfile)
+    let cmd = job.batchfile
+  endif
+  let argv = add(s:is_win ? ['cmd', '/c'] : ['sh', '-c'], cmd)
 
   if s:nvim
     call extend(job, {
@@ -1210,8 +1242,7 @@ function! s:spawn(name, cmd, opts)
       let job.lines   = ['Failed to start job']
     endif
   else
-    let params = has_key(a:opts, 'dir') ? [a:cmd, a:opts.dir] : [a:cmd]
-    let job.lines = s:lines(call('s:system', params))
+    let job.lines = s:lines(call('s:system', [cmd]))
     let job.error = v:shell_error != 0
     let job.running = 0
   endif
@@ -1231,6 +1262,9 @@ function! s:reap(name)
   call s:log(bullet, a:name, empty(result) ? 'OK' : result)
   call s:bar()
 
+  if has_key(job, 'batchfile') && !empty(job.batchfile)
+    call delete(job.batchfile)
+  endif
   call remove(s:jobs, a:name)
 endfunction
 
@@ -1297,7 +1331,7 @@ while 1 " Without TCO, Vim stack is bound to explode
 
   let name = keys(s:update.todo)[0]
   let spec = remove(s:update.todo, name)
-  let new  = !isdirectory(spec.dir)
+  let new  = empty(globpath(spec.dir, '.git', 1))
 
   call s:log(new ? '+' : '*', name, pull ? 'Updating ...' : 'Installing ...')
   redraw
@@ -1948,8 +1982,19 @@ function! s:update_ruby()
 EOF
 endfunction
 
+function! s:shellesc_cmd(arg)
+  let escaped = substitute(a:arg, '[&|<>()@^]', '^&', 'g')
+  let escaped = substitute(escaped, '%', '%%', 'g')
+  let escaped = substitute(escaped, '"', '\\^&', 'g')
+  let escaped = substitute(escaped, '\(\\\+\)\(\\^\)', '\1\1\2', 'g')
+  return '^"'.substitute(escaped, '\(\\\+\)$', '\1\1', '').'^"'
+endfunction
+
 function! s:shellesc(arg)
-  return '"'.escape(a:arg, '"').'"'
+  if &shell =~# 'cmd.exe$'
+    return s:shellesc_cmd(a:arg)
+  endif
+  return shellescape(a:arg)
 endfunction
 
 function! s:glob_dir(path)
@@ -1987,11 +2032,19 @@ endfunction
 
 function! s:system(cmd, ...)
   try
-    let [sh, shrd] = s:chsh(1)
+    let [sh, shellcmdflag, shrd] = s:chsh(1)
     let cmd = a:0 > 0 ? s:with_cd(a:cmd, a:1) : a:cmd
+    if s:is_win
+      let batchfile = tempname().'.bat'
+      call writefile(["@echo off\r", cmd . "\r"], batchfile)
+      let cmd = batchfile
+    endif
     return system(s:is_win ? '('.cmd.')' : cmd)
   finally
-    let [&shell, &shellredir] = [sh, shrd]
+    let [&shell, &shellcmdflag, &shellredir] = [sh, shellcmdflag, shrd]
+    if s:is_win
+      call delete(batchfile)
+    endif
   endtry
 endfunction
 
@@ -2206,15 +2259,16 @@ function! s:status()
   let unloaded = 0
   let [cnt, total] = [0, len(g:plugs)]
   for [name, spec] in items(g:plugs)
+    let is_dir = isdirectory(spec.dir)
     if has_key(spec, 'uri')
-      if isdirectory(spec.dir)
+      if is_dir
         let [err, _] = s:git_validate(spec, 1)
         let [valid, msg] = [empty(err), empty(err) ? 'OK' : err]
       else
         let [valid, msg] = [0, 'Not found. Try PlugInstall.']
       endif
     else
-      if isdirectory(spec.dir)
+      if is_dir
         let [valid, msg] = [1, 'OK']
       else
         let [valid, msg] = [0, 'Not found.']
@@ -2223,7 +2277,7 @@ function! s:status()
     let cnt += 1
     let ecnt += !valid
     " `s:loaded` entry can be missing if PlugUpgraded
-    if valid && get(s:loaded, name, -1) == 0
+    if is_dir && get(s:loaded, name, -1) == 0
       let unloaded = 1
       let msg .= ' (not loaded)'
     endif
@@ -2312,10 +2366,19 @@ function! s:preview_commit()
   endif
   setlocal previewwindow filetype=git buftype=nofile nobuflisted modifiable
   try
-    let [sh, shrd] = s:chsh(1)
-    execute 'silent %!cd' s:shellesc(g:plugs[name].dir) '&& git show --no-color --pretty=medium' sha
+    let [sh, shellcmdflag, shrd] = s:chsh(1)
+    let cmd = 'cd '.s:shellesc(g:plugs[name].dir).' && git show --no-color --pretty=medium '.sha
+    if s:is_win
+      let batchfile = tempname().'.bat'
+      call writefile(["@echo off\r", cmd . "\r"], batchfile)
+      let cmd = batchfile
+    endif
+    execute 'silent %!' cmd
   finally
-    let [&shell, &shellredir] = [sh, shrd]
+    let [&shell, &shellcmdflag, &shellredir] = [sh, shellcmdflag, shrd]
+    if s:is_win
+      call delete(batchfile)
+    endif
   endtry
   setlocal nomodifiable
   nnoremap <silent> <buffer> q :q<cr>
@@ -2357,7 +2420,11 @@ function! s:diff()
     call s:append_ul(2, origin ? 'Pending updates:' : 'Last update:')
     for [k, v] in plugs
       let range = origin ? '..origin/'.v.branch : 'HEAD@{1}..'
-      let diff = s:system_chomp('git log --graph --color=never --pretty=format:"%x01%h%x01%d%x01%s%x01%cr" '.s:shellesc(range), v.dir)
+      let cmd = 'git log --graph --color=never '.join(map(['--pretty=format:%x01%h%x01%d%x01%s%x01%cr', range], 's:shellesc(v:val)'))
+      if has_key(v, 'rtp')
+        let cmd .= ' -- '.s:shellesc(v.rtp)
+      endif
+      let diff = s:system_chomp(cmd, v.dir)
       if !empty(diff)
         let ref = has_key(v, 'tag') ? (' (tag: '.v.tag.')') : has_key(v, 'commit') ? (' '.v.commit) : ''
         call append(5, extend(['', '- '.k.':'.ref], map(s:lines(diff), 's:format_git_log(v:val)')))
@@ -2376,8 +2443,13 @@ function! s:diff()
         \ . (cnts[1] ? printf(' %d plugin(s) have pending updates.', cnts[1]) : ''))
 
   if cnts[0] || cnts[1]
-    nnoremap <silent> <buffer> <cr> :silent! call <SID>preview_commit()<cr>
-    nnoremap <silent> <buffer> o    :silent! call <SID>preview_commit()<cr>
+    nnoremap <silent> <buffer> <plug>(plug-preview) :silent! call <SID>preview_commit()<cr>
+    if empty(maparg("\<cr>", 'n'))
+      nmap <buffer> <cr> <plug>(plug-preview)
+    endif
+    if empty(maparg('o', 'n'))
+      nmap <buffer> o <plug>(plug-preview)
+    endif
   endif
   if cnts[0]
     nnoremap <silent> <buffer> X :call <SID>revert()<cr>