From b5acf6e0c1aedd68ec3423a45c7bf30599832708 Mon Sep 17 00:00:00 2001
From: "Justin M. Keyes" <justinkz@gmail.com>
Date: Fri, 2 Feb 2018 20:44:46 +0100
Subject: [PATCH] vim-patch:8.0.0700: segfault with QuitPre autocommand closes
 the window

Problem:    Segfault with QuitPre autocommand closes the window. (Marek)
Solution:   Check that the window pointer is still valid. (Christian Brabandt,
            closes vim/vim#1817)

https://github.com/vim/vim/commit/0ea5070d79c8a13fb2403280a72f968495b0fab7
---
 src/nvim/ex_docmd.c               |  1 +
 src/nvim/testdir/test_tabpage.vim | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 4f0208c5c3..34d8546653 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -5978,6 +5978,7 @@ static void ex_quit(exarg_T *eap)
   // Refuse to quit when locked or when the buffer in the last window is
   // being closed (can only happen in autocommands).
   if (curbuf_locked()
+      || !win_valid(wp)
       || (wp->w_buffer->b_nwindows == 1 && wp->w_buffer->b_locked > 0)) {
     return;
   }
diff --git a/src/nvim/testdir/test_tabpage.vim b/src/nvim/testdir/test_tabpage.vim
index 33139fcda0..51f2477209 100644
--- a/src/nvim/testdir/test_tabpage.vim
+++ b/src/nvim/testdir/test_tabpage.vim
@@ -473,5 +473,23 @@ func Test_tabnext_on_buf_unload2()
   endwhile
 endfunc
 
+func Test_close_on_quitpre()
+  " This once caused a crash
+  new
+  only
+  set bufhidden=delete
+  au QuitPre <buffer> close
+  tabnew tab1
+  tabnew tab2
+  1tabn
+  q!
+  call assert_equal(1, tabpagenr())
+  call assert_equal(2, tabpagenr('$'))
+  " clean up
+  while tabpagenr('$') > 1
+    bwipe!
+  endwhile
+  1b
+endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab