fix(extui): copy window config to new tabpage (#34308)

Problem:  When opening a new tabpage, extui windows are initialized with
          their default config. Window visiblity/dimensions on other
          tabpages may get out of sync with their buffer content.
Solution: Copy the config of the window to the new tabpage.
          No longer keep track of the various windows on each tabpage.
          Close windows on inactive tabpages instead (moving them could
          be more efficient but is currently not supported in the API).

1 files changed, 16 insertions, 15 deletions

diff --git a/runtime/lua/vim/_extui/shared.lua b/runtime/lua/vim/_extui/shared.lua
index 03c4cc42da..c142994334 100644
--- a/runtime/lua/vim/_extui/shared.lua
+++ b/runtime/lua/vim/_extui/shared.lua
@@ -5,10 +5,8 @@ local M = {
   ns = api.nvim_create_namespace('nvim._ext_ui'),
   augroup = api.nvim_create_augroup('nvim._ext_ui', {}),
   cmdheight = -1, -- 'cmdheight' option value set by user.
-  -- Map of tabpage ID to box/cmd/more/prompt window IDs.
-  wins = {}, ---@type { ['box'|'cmd'|'more'|'prompt']: integer }[]
+  wins = { box = -1, cmd = -1, more = -1, prompt = -1 },
   bufs = { box = -1, cmd = -1, more = -1, prompt = -1 },
-  tab = 0, -- Current tabpage.
   cfg = {
     enable = true,
     msg = { -- Options related to the message module.
@@ -31,13 +29,10 @@ local wincfg = { -- Default cfg for nvim_open_win().
   noautocmd = true,
 }
 
+local tab = 0
 --- Ensure the various buffers and windows have not been deleted.
 function M.tab_check_wins()
-  M.tab = api.nvim_get_current_tabpage()
-  if not M.wins[M.tab] then
-    M.wins[M.tab] = { box = -1, cmd = -1, more = -1, prompt = -1 }
-  end
-
+  local curtab = api.nvim_get_current_tabpage()
   for _, type in ipairs({ 'box', 'cmd', 'more', 'prompt' }) do
     local setopt = not api.nvim_buf_is_valid(M.bufs[type])
     if setopt then
@@ -50,8 +45,9 @@ function M.tab_check_wins()
     end
 
     if
-      not api.nvim_win_is_valid(M.wins[M.tab][type])
-      or not api.nvim_win_get_config(M.wins[M.tab][type]).zindex -- no longer floating
+      tab ~= curtab
+      or not api.nvim_win_is_valid(M.wins[type])
+      or not api.nvim_win_get_config(M.wins[type]).zindex -- no longer floating
     then
       local top = { vim.opt.fcs:get().horiz or o.ambw == 'single' and '─' or '-', 'WinSeparator' }
       local border = (type == 'more' or type == 'prompt') and { '', top, '', '', '', '', '', '' }
@@ -66,13 +62,17 @@ function M.tab_check_wins()
         zindex = 200 - (type == 'more' and 1 or 0),
         _cmdline_offset = type == 'cmd' and 0 or nil,
       })
-      M.wins[M.tab][type] = api.nvim_open_win(M.bufs[type], false, cfg)
+      if tab ~= curtab and api.nvim_win_is_valid(M.wins[type]) then
+        cfg = api.nvim_win_get_config(M.wins[type])
+        api.nvim_win_close(M.wins[type], true)
+      end
+      M.wins[type] = api.nvim_open_win(M.bufs[type], false, cfg)
       if type == 'cmd' then
-        api.nvim_win_set_hl_ns(M.wins[M.tab][type], M.ns)
+        api.nvim_win_set_hl_ns(M.wins[type], M.ns)
       end
       setopt = true
-    elseif api.nvim_win_get_buf(M.wins[M.tab][type]) ~= M.bufs[type] then
-      api.nvim_win_set_buf(M.wins[M.tab][type], M.bufs[type])
+    elseif api.nvim_win_get_buf(M.wins[type]) ~= M.bufs[type] then
+      api.nvim_win_set_buf(M.wins[type], M.bufs[type])
       setopt = true
     end
 
@@ -84,7 +84,7 @@ function M.tab_check_wins()
       end
 
       -- Fire a FileType autocommand with window context to let the user reconfigure local options.
-      api.nvim_win_call(M.wins[M.tab][type], function()
+      api.nvim_win_call(M.wins[type], function()
         api.nvim_set_option_value('wrap', true, { scope = 'local' })
         api.nvim_set_option_value('linebreak', false, { scope = 'local' })
         api.nvim_set_option_value('smoothscroll', true, { scope = 'local' })
@@ -95,6 +95,7 @@ function M.tab_check_wins()
       end)
     end
   end
+  tab = curtab
 end
 
 return M