diff --git a/autoload/plug.vim b/autoload/plug.vim
index ceb2762..9ebcf53 100644
--- a/autoload/plug.vim
+++ b/autoload/plug.vim
@@ -605,7 +605,7 @@ 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
@@ -908,7 +908,7 @@ 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, ' ')
@@ -2246,15 +2246,16 @@ 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.']
@@ -2263,7 +2264,7 @@ 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
@@ -2406,7 +2407,7 @@ 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 diff = s:system_chomp('git log --graph --color=never '.join(map(['--pretty=format:%x01%h%x01%d%x01%s%x01%cr', range], 's:shellesc(v:val)')), 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)')))