From d1ca5519834cfa2eb25ba48c62e5b5d21905e10f Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Mon, 26 May 2025 06:51:15 +0800
Subject: [PATCH] vim-patch:9.1.1407: Can't use getpos('v') in OptionSet when
 using setbufvar() (#34177)

Problem:  Can't use getpos('v') in OptionSet when using setbufvar().
Solution: Don't reset Visual selection when switching to the same
          buffer (zeertzjq).

closes: vim/vim#17373

https://github.com/vim/vim/commit/5717ee33db0048a496e8bed0b0cb20133b3f76ca
(cherry picked from commit bd01bd6564790d977095447ae70082c97fbbd480)
---
 src/nvim/autocmd.c                      |  9 ++++++---
 test/functional/legacy/autocmd_spec.lua | 24 ++++++++++++++++++++++++
 test/functional/lua/vim_spec.lua        | 11 +++++++++++
 test/old/testdir/test_autocmd.vim       | 22 ++++++++++++++++++++++
 4 files changed, 63 insertions(+), 3 deletions(-)

diff --git a/src/nvim/autocmd.c b/src/nvim/autocmd.c
index 53cd861a9c..189e9d558b 100644
--- a/src/nvim/autocmd.c
+++ b/src/nvim/autocmd.c
@@ -1268,9 +1268,10 @@ void aucmd_prepbuf(aco_save_T *aco, buf_T *buf)
 {
   win_T *win;
   bool need_append = true;  // Append `aucmd_win` to the window list.
+  const bool same_buffer = buf == curbuf;
 
   // Find a window that is for the new buffer
-  if (buf == curbuf) {  // be quick when buf is curbuf
+  if (same_buffer) {  // be quick when buf is curbuf
     win = curwin;
   } else {
     win = NULL;
@@ -1360,9 +1361,11 @@ void aucmd_prepbuf(aco_save_T *aco, buf_T *buf)
   aco->new_curwin_handle = curwin->handle;
   set_bufref(&aco->new_curbuf, curbuf);
 
-  // disable the Visual area, the position may be invalid in another buffer
   aco->save_VIsual_active = VIsual_active;
-  VIsual_active = false;
+  if (!same_buffer) {
+    // disable the Visual area, position may be invalid in another buffer
+    VIsual_active = false;
+  }
 }
 
 /// Cleanup after executing autocommands for a (hidden) buffer.
diff --git a/test/functional/legacy/autocmd_spec.lua b/test/functional/legacy/autocmd_spec.lua
index 1071776b68..3a40ca4df8 100644
--- a/test/functional/legacy/autocmd_spec.lua
+++ b/test/functional/legacy/autocmd_spec.lua
@@ -11,6 +11,30 @@ local eq = t.eq
 
 before_each(clear)
 
+local function expected_empty()
+  eq({}, api.nvim_get_vvar('errors'))
+end
+
+-- oldtest: Test_get_Visual_selection_in_curbuf_autocmd()
+it('autocmd can get Visual selection when using setbufvar() on curbuf', function()
+  n.exec([[
+    new
+    autocmd OptionSet list let b:text = getregion(getpos('.'), getpos('v'))
+    call setline(1, 'foo bar baz')
+
+    normal! gg0fbvtb
+    setlocal list
+    call assert_equal(['bar '], b:text)
+    exe "normal! \<Esc>"
+
+    normal! v0
+    call setbufvar('%', '&list', v:false)
+    call assert_equal(['foo bar '], b:text)
+    exe "normal! \<Esc>"
+  ]])
+  expected_empty()
+end)
+
 -- oldtest: Test_autocmd_invalidates_undo_on_textchanged()
 it('no E440 in quickfix window when autocommand invalidates undo', function()
   write_file(
diff --git a/test/functional/lua/vim_spec.lua b/test/functional/lua/vim_spec.lua
index cbd571439d..524974adc7 100644
--- a/test/functional/lua/vim_spec.lua
+++ b/test/functional/lua/vim_spec.lua
@@ -3930,6 +3930,17 @@ stack traceback:
       ]]
       )
     end)
+
+    it('can get Visual selection in current buffer #34162', function()
+      insert('foo bar baz')
+      feed('gg0fbvtb')
+      local text = exec_lua([[
+        return vim.api.nvim_buf_call(0, function()
+          return vim.fn.getregion(vim.fn.getpos('.'), vim.fn.getpos('v'))
+        end)
+      ]])
+      eq({ 'bar ' }, text)
+    end)
   end)
 
   describe('vim.api.nvim_win_call', function()
diff --git a/test/old/testdir/test_autocmd.vim b/test/old/testdir/test_autocmd.vim
index a35049d468..c25f2e5814 100644
--- a/test/old/testdir/test_autocmd.vim
+++ b/test/old/testdir/test_autocmd.vim
@@ -3458,6 +3458,28 @@ func Test_Visual_doautoall_redraw()
   %bwipe!
 endfunc
 
+func Test_get_Visual_selection_in_curbuf_autocmd()
+  throw 'Skipped: use test/functional/legacy/autocmd_spec.lua'
+  call test_override('starting', 1)
+  new
+  autocmd OptionSet list let b:text = getregion(getpos('.'), getpos('v'))
+  call setline(1, 'foo bar baz')
+
+  normal! gg0fbvtb
+  setlocal list
+  call assert_equal(['bar '], b:text)
+  exe "normal! \<Esc>"
+
+  normal! v0
+  call setbufvar('%', '&list', v:false)
+  call assert_equal(['foo bar '], b:text)
+  exe "normal! \<Esc>"
+
+  autocmd! OptionSet list
+  bwipe!
+  call test_override('starting', 0)
+endfunc
+
 " This was using freed memory.
 func Test_BufNew_arglocal()
   arglocal