vim-patch:8.2.3862: crash on exit with EXITFREE and using win_execute()

Problem:    Crash on exit with EXITFREE and using win_execute().
Solution:   Also save and restore tp_topframe. (issue vim/vim#9374)

https://github.com/vim/vim/commit/dab17a0689a2f31f69f428975f84b0c3c7ba3030

Couldn't repro the crash in the test, but I only care about this patch so
switch_win sets topframe properly for win_split_ins in nvim_open_win and
nvim_win_set_config.
Add a test using nvim_win_call and :wincmd, as I couldn't repro the issue via
nvim_open_win or nvim_win_set_config (though it's clear they're affected by this
patch).

That said, at that point, could just use {un}use_tabpage inside switch_win
instead, which also updates tp_curwin (though maybe continue to not set it in
restore_win). That would also fix possible inconsistent behaviour such as:

:call win_execute(w, "let curwin_nr1 = tabpagewinnr(1)")
:let curwin_nr2 = tabpagewinnr(1)

Where it's possible for curwin_nr1 != curwin_nr2 if these commands are run from
the 1st tabpage, but window "w" is in the 2nd (as the 1st tabpage's tp_curwin
may still be invalid). I'll probably PR a fix for that later in Vim.

Co-authored-by: Bram Moolenaar <Bram@vim.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/test/functional/lua/vim_spec.lua b/test/functional/lua/vim_spec.lua
index a262d239e8..add3df6d8a 100644
--- a/test/functional/lua/vim_spec.lua
+++ b/test/functional/lua/vim_spec.lua
@@ -3664,6 +3664,20 @@ describe('lua stdlib', function()
       ]]
       )
     end)
+
+    it('layout in current tabpage does not affect windows in others', function()
+      command('tab split')
+      local t2_move_win = api.nvim_get_current_win()
+      command('vsplit')
+      local t2_other_win = api.nvim_get_current_win()
+      command('tabprevious')
+      matches('E36: Not enough room$', pcall_err(command, 'execute "split|"->repeat(&lines)'))
+      command('vsplit')
+
+      -- Without vim-patch:8.2.3862, this gives E36, despite just the 1st tabpage being full.
+      exec_lua('vim.api.nvim_win_call(..., function() vim.cmd.wincmd "J" end)', t2_move_win)
+      eq({ 'col', { { 'leaf', t2_other_win }, { 'leaf', t2_move_win } } }, fn.winlayout(2))
+    end)
   end)
 
   describe('vim.iconv', function()