From f96e401b7e218669e639987eba73b6c51a776368 Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Tue, 6 Jan 2026 20:08:24 +0800
Subject: [PATCH] vim-patch:9.1.2055: Division by zero in :file after failing
 to wipe buffer (#37268)

Problem:  Division by zero in :file after failing to wipe buffer
          (after 8.2.4631).
Solution: Still call buf_clear_file() when failing to wipe buffer
          (zeertzjq).

closes: vim/vim#19088

https://github.com/vim/vim/commit/1aa5ca4ecbef76a4df3a228e115eae7cc939cc86
(cherry picked from commit 97bfc0c99b33b2a35c5513c820c4da0c32f1006e)
---
 src/nvim/buffer.c                 |  7 ++-----
 test/old/testdir/test_autocmd.vim | 25 ++++++++++++++++++++++++-
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index aec0edbbf5..b6ee21b073 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -698,14 +698,11 @@ bool close_buffer(win_T *win, buf_T *buf, int action, bool abort_if_last, bool i
   }
 
   // Remove the buffer from the list.
-  if (wipe_buf) {
+  // Do not wipe out the buffer if it is used in a window.
+  if (wipe_buf && buf->b_nwindows <= 0) {
     if (clear_w_buf) {
       win->w_buffer = NULL;
     }
-    // Do not wipe out the buffer if it is used in a window.
-    if (buf->b_nwindows > 0) {
-      return true;
-    }
     FOR_ALL_TAB_WINDOWS(tp, wp) {
       mark_forget_file(wp, buf->b_fnum);
     }
diff --git a/test/old/testdir/test_autocmd.vim b/test/old/testdir/test_autocmd.vim
index 92f034c31b..5d2d12d2a5 100644
--- a/test/old/testdir/test_autocmd.vim
+++ b/test/old/testdir/test_autocmd.vim
@@ -3376,7 +3376,7 @@ func Test_BufReadPre_changebuf()
   close!
 endfunc
 
-" Test for BufWipeouti autocmd changing the current buffer when reading a file
+" Test for BufWipeout autocmd changing the current buffer when reading a file
 " in an empty buffer with 'f' flag in 'cpo'
 func Test_BufDelete_changebuf()
   new
@@ -3662,6 +3662,29 @@ func Test_bufwipeout_changes_window()
   %bwipe!
 endfunc
 
+func Test_autocmd_prevent_buf_wipe()
+  " Xa must be the first buffer so that win_close_othertab() puts it in
+  " another window, which causes wiping the buffer to fail.
+  %bwipe!
+
+  file Xa
+  call setline(1, 'foo')
+  setlocal bufhidden=wipe
+  tabnew Xb
+  setlocal bufhidden=wipe
+  autocmd BufUnload Xa ++once ++nested tabonly
+  autocmd BufWinLeave Xb ++once tabnext
+  tabfirst
+
+  edit! Xc
+  call assert_equal('Xc', bufname('%'))
+  tabnext
+  call assert_equal('Xa', bufname('%'))
+  call assert_equal("\n\"Xa\" --No lines in buffer--", execute('file'))
+
+  %bwipe!
+endfunc
+
 func Test_v_event_readonly()
   autocmd CompleteChanged * let v:event.width = 0
   call assert_fails("normal! i\<C-X>\<C-V>", 'E46:')