vim-patch:9.0.1439: start Insert mode when accessing a hidden prompt buffer (#22867)

Problem:    Start Insert mode when accessing a hidden prompt buffer.
Solution:   Call leaving_window() in aucmd_restbuf(). (Thorben Tröbst,
            closes vim/vim#12148, closes vim/vim#12147)

https://github.com/vim/vim/commit/cde8de034524d00aba4ff4142e658baff511e12d

Cherry-pick test_prompt_buffer.vim changes from patch 9.0.0631.

Co-authored-by: orbital <orbital@holgerines.de>

4 files changed, 84 insertions, 8 deletions

diff --git a/src/nvim/autocmd.c b/src/nvim/autocmd.c
index 578542adfe..9b4cb336bc 100644
--- a/src/nvim/autocmd.c
+++ b/src/nvim/autocmd.c
@@ -1495,7 +1495,9 @@ void aucmd_restbuf(aco_save_T *aco)
       }
     }
 win_found:
-
+    // May need to stop Insert mode if we were in a prompt buffer.
+    leaving_window(curwin);
+    // Remove the window.
     win_remove(curwin, NULL);
     pmap_del(handle_T)(&window_handles, curwin->handle);
     if (curwin->w_grid_alloc.chars != NULL) {
diff --git a/src/nvim/window.c b/src/nvim/window.c
index 762ad13ba3..48663c5a20 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -2417,7 +2417,7 @@ static void win_equal_rec(win_T *next_curwin, bool current, frame_T *topfr, int
   }
 }
 
-static void leaving_window(win_T *const win)
+void leaving_window(win_T *const win)
   FUNC_ATTR_NONNULL_ALL
 {
   // Only matters for a prompt window.
diff --git a/test/functional/legacy/prompt_buffer_spec.lua b/test/functional/legacy/prompt_buffer_spec.lua
index 602593d632..6c72cde855 100644
--- a/test/functional/legacy/prompt_buffer_spec.lua
+++ b/test/functional/legacy/prompt_buffer_spec.lua
@@ -3,9 +3,11 @@ local Screen = require('test.functional.ui.screen')
 local feed = helpers.feed
 local source = helpers.source
 local clear = helpers.clear
+local command = helpers.command
 local poke_eventloop = helpers.poke_eventloop
 local meths = helpers.meths
 local eq = helpers.eq
+local neq = helpers.neq
 
 describe('prompt buffer', function()
   local screen
@@ -14,9 +16,11 @@ describe('prompt buffer', function()
     clear()
     screen = Screen.new(25, 10)
     screen:attach()
-    source([[
-      set laststatus=0 nohidden
+    command('set laststatus=0 nohidden')
+  end)
 
+  local function source_script()
+    source([[
       func TextEntered(text)
         if a:text == "exit"
           " Reset &modified to allow the buffer to be closed.
@@ -63,7 +67,7 @@ describe('prompt buffer', function()
       ~                        |
       -- INSERT --             |
     ]])
-  end)
+  end
 
   after_each(function()
     screen:detach()
@@ -71,6 +75,7 @@ describe('prompt buffer', function()
 
   -- oldtest: Test_prompt_basic()
   it('works', function()
+    source_script()
     feed("hello\n")
     screen:expect([[
       cmd: hello               |
@@ -101,6 +106,7 @@ describe('prompt buffer', function()
 
   -- oldtest: Test_prompt_editing()
   it('editing', function()
+    source_script()
     feed("hello<BS><BS>")
     screen:expect([[
       cmd: hel^                 |
@@ -170,6 +176,7 @@ describe('prompt buffer', function()
 
   -- oldtest: Test_prompt_switch_windows()
   it('switch windows', function()
+    source_script()
     feed("<C-O>:call SwitchWindows()<CR>")
     screen:expect{grid=[[
       cmd:                     |
@@ -213,11 +220,41 @@ describe('prompt buffer', function()
 
   -- oldtest: Test_prompt_while_writing_to_hidden_buffer()
   it('keeps insert mode after aucmd_restbuf in callback', function()
+    source_script()
     source [[
       let s:buf = nvim_create_buf(1, 1)
       call timer_start(0, {-> nvim_buf_set_lines(s:buf, -1, -1, 0, ['walrus'])})
     ]]
     poke_eventloop()
-    eq({ mode = "i", blocking = false }, meths.get_mode())
+    eq({ mode = 'i', blocking = false }, meths.get_mode())
+  end)
+
+  -- oldtest: Test_prompt_appending_while_hidden()
+  it('accessing hidden prompt buffer does not start insert mode', function()
+    local prev_win = meths.get_current_win()
+    source([[
+      new prompt
+      set buftype=prompt
+      set bufhidden=hide
+
+      func s:TextEntered(text)
+          if a:text == 'exit'
+              close
+          endif
+          let g:entered = a:text
+      endfunc
+      call prompt_setcallback(bufnr(), function('s:TextEntered'))
+
+      func DoAppend()
+        call appendbufline('prompt', '$', 'Test')
+      endfunc
+    ]])
+    feed('asomething<CR>')
+    eq('something', meths.get_var('entered'))
+    neq(prev_win, meths.get_current_win())
+    feed('exit<CR>')
+    eq(prev_win, meths.get_current_win())
+    command('call DoAppend()')
+    eq({ mode = 'n', blocking = false }, meths.get_mode())
   end)
 end)
diff --git a/test/old/testdir/test_prompt_buffer.vim b/test/old/testdir/test_prompt_buffer.vim
index b1288b4892..43d8bb4789 100644
--- a/test/old/testdir/test_prompt_buffer.vim
+++ b/test/old/testdir/test_prompt_buffer.vim
@@ -238,7 +238,7 @@ func Test_prompt_while_writing_to_hidden_buffer()
         \ done'], #{out_io: 'buffer', out_name: ''})
     startinsert
   END
-  eval script->writefile(scriptName)
+  eval script->writefile(scriptName, 'D')
 
   let buf = RunVimInTerminal('-S ' .. scriptName, {})
   call WaitForAssert({-> assert_equal('cmd:', term_getline(buf, 1))})
@@ -251,7 +251,44 @@ func Test_prompt_while_writing_to_hidden_buffer()
   call WaitForAssert({-> assert_equal('cmd:testtesttest', term_getline(buf, 1))})
 
   call StopVimInTerminal(buf)
-  call delete(scriptName)
+endfunc
+
+func Test_prompt_appending_while_hidden()
+  call CanTestPromptBuffer()
+
+  let script =<< trim END
+      new prompt
+      set buftype=prompt
+      set bufhidden=hide
+
+      func s:TextEntered(text)
+          if a:text == 'exit'
+              close
+          endif
+          echowin 'Entered:' a:text
+      endfunc
+      call prompt_setcallback(bufnr(), function('s:TextEntered'))
+
+      func DoAppend()
+        call appendbufline('prompt', '$', 'Test')
+      endfunc
+  END
+  call writefile(script, 'XpromptBuffer', 'D')
+
+  let buf = RunVimInTerminal('-S XpromptBuffer', {'rows': 10})
+  call TermWait(buf)
+
+  call term_sendkeys(buf, "asomething\<CR>")
+  call TermWait(buf)
+
+  call term_sendkeys(buf, "exit\<CR>")
+  call TermWait(buf)
+
+  call term_sendkeys(buf, ":call DoAppend()\<CR>")
+  call TermWait(buf)
+  call assert_notmatch('-- INSERT --', term_getline(buf, 10))
+
+  call StopVimInTerminal(buf)
 endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab