From f32bdf1a7ba0bf5c2bea5965d765e3a03af9e00c Mon Sep 17 00:00:00 2001
From: Tim Pope <code@tpope.net>
Date: Sat, 21 Jun 2014 13:44:44 -0400
Subject: [PATCH] Only :diffoff our own diffs

Closes #395.
---
 plugin/fugitive.vim | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/plugin/fugitive.vim b/plugin/fugitive.vim
index 34e7b68..891bbe6 100644
--- a/plugin/fugitive.vim
+++ b/plugin/fugitive.vim
@@ -1408,19 +1408,25 @@ call s:command("-bar -nargs=* -complete=customlist,s:EditComplete Gsdiff :execut
 augroup fugitive_diff
   autocmd!
   autocmd BufWinLeave *
-        \ if getwinvar(bufwinnr(+expand('<abuf>')), '&diff') &&
-        \     s:diff_window_count() == 2 &&
-        \     !empty(getbufvar(+expand('<abuf>'), 'git_dir')) |
+        \ if s:can_diffoff(+expand('<abuf>')) && s:diff_window_count() == 2 |
         \   call s:diffoff_all(getbufvar(+expand('<abuf>'), 'git_dir')) |
         \ endif
   autocmd BufWinEnter *
-        \ if getwinvar(bufwinnr(+expand('<abuf>')), '&diff') &&
-        \     s:diff_window_count() == 1 &&
-        \     !empty(getbufvar(+expand('<abuf>'), 'git_dir')) |
+        \ if s:can_diffoff(+expand('<abuf>')) && s:diff_window_count() == 1 |
         \   call s:diffoff() |
         \ endif
 augroup END
 
+function! s:can_diffoff(buf) abort
+  return getwinvar(bufwinnr(a:buf), '&diff') &&
+        \ !empty(getbufvar(a:buf, 'git_dir')) &&
+        \ !empty(getwinvar(bufwinnr(a:buf), 'fugitive_diff_restore'))
+endfunction
+
+function! fugitive#can_diffoff(buf) abort
+  return s:can_diffoff(a:buf)
+endfunction
+
 function! s:diff_horizontal(count) abort
   let fdc = matchstr(&diffopt, 'foldcolumn:\zs\d\+')
   if &diffopt =~# 'horizontal' && &diffopt !~# 'vertical'