From e750f7c357f335b186ceed1063d5aee1d0a762c0 Mon Sep 17 00:00:00 2001
From: Shiva Priyan <pshanmugashiva@gmail.com>
Date: Mon, 22 Jun 2026 21:13:18 -0400
Subject: [PATCH] vim-patch:9.2.0702: :windo and :tabdo create an extra window
 with 'winfixbuf' (#40358)

Problem:  With 'winfixbuf' set in the current window, :windo and :tabdo
          create an extra split window, even though they only visit
          existing windows/tabpages and don't change the current
          window's buffer (Collin Kennedy)
Solution: Skip the 'winfixbuf' escape in ex_listdo() for :windo and
          :tabdo (ShivaPriyanShanmuga)

fixes:  vim/vim#14301
closes: vim/vim#20600

https://github.com/vim/vim/commit/5767d80b3794b17e5b61afec966fdeb7c0c4506f
---
 src/nvim/ex_cmds2.c                 |  5 +++-
 test/old/testdir/test_winfixbuf.vim | 41 +++++++++++++++++++----------
 2 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/src/nvim/ex_cmds2.c b/src/nvim/ex_cmds2.c
index f90cf0d144..b34d0326ce 100644
--- a/src/nvim/ex_cmds2.c
+++ b/src/nvim/ex_cmds2.c
@@ -459,7 +459,10 @@ int buf_write_all(buf_T *buf, bool forceit)
 /// ":argdo", ":windo", ":bufdo", ":tabdo", ":cdo", ":ldo", ":cfdo" and ":lfdo"
 void ex_listdo(exarg_T *eap)
 {
-  if (curwin->w_p_wfb) {
+  // ":windo" and ":tabdo" only visit existing windows/tabpages, they don't
+  // change the current window's buffer, so they can't escape a 'winfixbuf'
+  // window (which would create a split).
+  if (curwin->w_p_wfb && eap->cmdidx != CMD_windo && eap->cmdidx != CMD_tabdo) {
     if ((eap->cmdidx == CMD_ldo || eap->cmdidx == CMD_lfdo) && !eap->forceit) {
       // Disallow :ldo if 'winfixbuf' is applied
       emsg(_(e_winfixbuf_cannot_go_to_buffer));
diff --git a/test/old/testdir/test_winfixbuf.vim b/test/old/testdir/test_winfixbuf.vim
index a040b3f2da..c9a557b1c5 100644
--- a/test/old/testdir/test_winfixbuf.vim
+++ b/test/old/testdir/test_winfixbuf.vim
@@ -2860,36 +2860,34 @@ func Test_tNext()
   set tags&
 endfunc
 
-" Call :tabdo and choose the next available 'nowinfixbuf' window.
-func Test_tabdo_choose_available_window()
+" Call :tabdo and stay in the 'winfixbuf' window: it only visits tabpages and
+" doesn't change the current buffer, so it must not switch to another window
+" even when a 'nowinfixbuf' window is available.
+func Test_tabdo_stay_in_winfixbuf_window()
   call s:reset_all_buffers()
 
   let [l:first, _] = s:make_args_list()
 
-  " Make a split window that is 'nowinfixbuf' but make it the second-to-last
-  " window so that :tabdo will first try the 'winfixbuf' window, pass over it,
-  " and prefer the other 'nowinfixbuf' window, instead.
-  "
   " +-------------------+
   " |   'nowinfixbuf'   |
   " +-------------------+
   " |    'winfixbuf'    |  <-- Cursor is here
   " +-------------------+
   split
-  let l:nowinfixbuf_window = win_getid()
   " Move to the 'winfixbuf' window now
   exe "normal \<C-w>j"
   let l:winfixbuf_window = win_getid()
 
   let l:expected_windows = s:get_windows_count()
   tabdo echo ''
-  call assert_equal(l:nowinfixbuf_window, win_getid())
+  call assert_equal(l:winfixbuf_window, win_getid())
   call assert_equal(l:first, bufnr())
   call assert_equal(l:expected_windows, s:get_windows_count())
 endfunc
 
-" Call :tabdo and create a new split window if all available windows are 'winfixbuf'.
-func Test_tabdo_make_new_window()
+" Call :tabdo and do not create a new window even when the only window is
+" 'winfixbuf'.
+func Test_tabdo_no_new_window()
   call s:reset_all_buffers()
 
   let [l:first, _] = s:make_buffers_list()
@@ -2899,11 +2897,9 @@ func Test_tabdo_make_new_window()
   let l:current_windows = s:get_windows_count()
 
   tabdo echo ''
-  call assert_notequal(l:current, win_getid())
+  call assert_equal(l:current, win_getid())
   call assert_equal(l:first, bufnr())
-  exe "normal \<C-w>j"
-  call assert_equal(l:first, bufnr())
-  call assert_equal(l:current_windows + 1, s:get_windows_count())
+  call assert_equal(l:current_windows, s:get_windows_count())
 endfunc
 
 " Fail :tag but :tag! is allowed
@@ -3217,6 +3213,23 @@ func Test_windo()
   call assert_equal(l:current_window, win_getid())
 endfunc
 
+" Call :windo and do not create a new window even when the only window is
+" 'winfixbuf'.
+func Test_windo_no_new_window()
+  call s:reset_all_buffers()
+
+  let [l:first, _] = s:make_buffers_list()
+  exe $"buffer! {l:first}"
+
+  let l:current = win_getid()
+  let l:current_windows = s:get_windows_count()
+
+  windo echo ''
+  call assert_equal(l:current, win_getid())
+  call assert_equal(l:first, bufnr())
+  call assert_equal(l:current_windows, s:get_windows_count())
+endfunc
+
 " Fail :wnext but :wnext! is allowed
 func Test_wnext()
   call s:reset_all_buffers()