feat(window/ui): add splitkeep option (#19243)

vim-patch:9.0.0445: when opening/closing window text moves up/down

Problem:    When opening/closing window text moves up/down.
Solution:   Add the 'splitscroll' option.  When off text will keep its
            position as much as possible.
https://github.com/vim/vim/commit/29ab524358ba429bcf6811710afc97a978641f0b

vim-patch:9.0.0455: a few problems with 'splitscroll'

Problem:    A few problems with 'splitscroll'.
Solution:   Fix 'splitscroll' problems. (Luuk van Baal, closes vim/vim#11117)
https://github.com/vim/vim/commit/5ed391708a62b4ebaa84dd23e32a416e5c3383d9

vim-patch:9.0.0461: 'scroll' is not always updated

Problem:    'scroll' is not always updated.
Solution:   Call win_init_size() at the right place.
https://github.com/vim/vim/commit/470a14140bc06f1653edf26ab0b3c9b801080353

vim-patch:9.0.0465: cursor moves when cmdwin is closed when 'splitscroll' is off

Problem:    Cursor moves when cmdwin is closed when 'splitscroll' is off.
Solution:   Temporarily set 'splitscroll' when jumping back to the original
            window. (closes vim/vim#11128)
https://github.com/vim/vim/commit/e697d488901b6321ddaad68b553f0a434c97d849

vim-patch:9.0.0469: cursor moves if cmdwin is closed when 'splitscroll' is off

Problem:    Cursor moves if cmdwin is closed when 'splitscroll' is off.
Solution:   Skip win_fix_cursor if called when cmdwin is open or closing.
            (Luuk van Baal, closes vim/vim#11134)
https://github.com/vim/vim/commit/3735f11050616652525bf80b4fbcb2b3bfeab113

vim-patch:9.0.0478: test for 'splitscroll' takes too much time

Problem:    Test for 'splitscroll' takes too much time.
Solution:   Only test some of the combinations. (Luuk van Baal, closes vim/vim#11139)
https://github.com/vim/vim/commit/594f9e09cd68e6277b8aa08094405bc642c5792a

vim-patch:9.0.0486: text scrolled with 'nosplitscroll', autocmd win and help

Problem:    Text scrolled with 'nosplitscroll', autocmd win opened and help
            window closed.
Solution:   Skip win_fix_scroll() in more situations. (Luuk van Baal,
            closes vim/vim#11150)
https://github.com/vim/vim/commit/d5bc762dea1fd32fa04342f8149f95ccfc3b9709

vim-patch:9.0.0505: various problems with 'nosplitscroll'

Problem:    Various problems with 'nosplitscroll'.
Solution:   Fix 'nosplitscroll' problems. (Luuk van Baal, closes vim/vim#11166)
https://github.com/vim/vim/commit/faf1d412f5e3665021500b528c0e7301eb02bf0b

vim-patch:9.0.0555: scrolling with 'nosplitscroll' in callback changing curwin

Problem:    Scrolling with 'nosplitscroll' in callback changing curwin.
Solution:   Invalidate w_cline_row in the right place. (Luuk van Baal,
            closes vim/vim#11185)
https://github.com/vim/vim/commit/20e58561abc4116f3bfbafaef242d886dd77b303

vim-patch:9.0.0603: with 'nosplitscroll' folds are not handled correctly

Problem:    With 'nosplitscroll' folds are not handled correctly.
Solution:   Take care of closed folds when moving the cursor. (Luuk van Baal,
            closes vim/vim#11234)
https://github.com/vim/vim/commit/7c1cbb6cd437c6e0c3ccc05840cc931108b4a60a

vim-patch:9.0.0605: dump file missing

Problem:    Dump file missing.
Solution:   Add the missing dump file. (issue vim/vim#11234)
https://github.com/vim/vim/commit/439a2ba1749463718b6ce1e1375b68c7b7cff808

vim-patch:9.0.0647: the 'splitscroll' option is not a good name

Problem:    The 'splitscroll' option is not a good name.
Solution:   Rename 'splitscroll' to 'splitkeep' and make it a string option,
            also supporting "topline". (Luuk van Baal, closes vim/vim#11258)
https://github.com/vim/vim/commit/13ece2ae1d09009d3fb8acf858c288e7848ecdac

vim-patch:9.0.0667: ml_get error when 'splitkeep' is "screen"

Problem:    ml_get error when 'splitkeep' is "screen". (Marius Gedminas)
Solution:   Check the botline is not too large. (Luuk van Baal,
            closes vim/vim#11293, closes vim/vim#11292)
https://github.com/vim/vim/commit/346823d3e5668b99d2c2fd920e7f215e21ad3ea7

1 files changed, 196 insertions, 0 deletions

diff --git a/test/functional/legacy/window_cmd_spec.lua b/test/functional/legacy/window_cmd_spec.lua
new file mode 100644
index 0000000000..8b89c55f5b
--- /dev/null
+++ b/test/functional/legacy/window_cmd_spec.lua
@@ -0,0 +1,196 @@
+local helpers = require('test.functional.helpers')(after_each)
+local Screen = require('test.functional.ui.screen')
+local clear = helpers.clear
+local exec = helpers.exec
+local exec_lua = helpers.exec_lua
+local feed = helpers.feed
+
+describe('splitkeep', function()
+  local screen = Screen.new()
+  before_each(function()
+    clear('--cmd', 'set splitkeep=screen')
+    screen:attach()
+  end)
+
+  -- oldtest: Test_splitkeep_callback()
+  it('does not scroll when split in callback', function()
+    exec([[
+      call setline(1, range(&lines))
+      function C1(a, b, c)
+        split | wincmd p
+      endfunction
+      function C2(a, b, c)
+        close | split
+      endfunction
+    ]])
+    exec_lua([[
+      vim.api.nvim_set_keymap("n", "j", "", { callback = function()
+        vim.cmd("call jobstart([&sh, &shcf, 'true'], { 'on_exit': 'C1' })")
+      end
+    })]])
+    exec_lua([[
+      vim.api.nvim_set_keymap("n", "t", "", { callback = function()
+        vim.api.nvim_set_current_win(
+          vim.api.nvim_open_win(vim.api.nvim_create_buf(false, {}), false, {
+          width = 10,
+            relative = "cursor",
+            height = 4,
+            row = 0,
+            col = 0,
+          }))
+          vim.cmd("call termopen([&sh, &shcf, 'true'], { 'on_exit': 'C2' })")
+      end
+    })]])
+    feed('j')
+    screen:expect([[
+      0                                                    |
+      1                                                    |
+      2                                                    |
+      3                                                    |
+      4                                                    |
+      5                                                    |
+      [No Name] [+]                                        |
+      ^7                                                    |
+      8                                                    |
+      9                                                    |
+      10                                                   |
+      11                                                   |
+      [No Name] [+]                                        |
+                                                           |
+    ]])
+    feed(':quit<CR>Ht')
+    screen:expect([[
+      ^0                                                    |
+      1                                                    |
+      2                                                    |
+      3                                                    |
+      4                                                    |
+      5                                                    |
+      [No Name] [+]                                        |
+      7                                                    |
+      8                                                    |
+      9                                                    |
+      10                                                   |
+      11                                                   |
+      [No Name] [+]                                        |
+      :quit                                                |
+    ]])
+    feed(':set sb<CR>:quit<CR>Gj')
+    screen:expect([[
+      1                                                    |
+      2                                                    |
+      3                                                    |
+      4                                                    |
+      ^5                                                    |
+      [No Name] [+]                                        |
+      7                                                    |
+      8                                                    |
+      9                                                    |
+      10                                                   |
+      11                                                   |
+      12                                                   |
+      [No Name] [+]                                        |
+      :quit                                                |
+    ]])
+    feed(':quit<CR>Gt')
+    screen:expect([[
+      1                                                    |
+      2                                                    |
+      3                                                    |
+      4                                                    |
+      5                                                    |
+      [No Name] [+]                                        |
+      7                                                    |
+      8                                                    |
+      9                                                    |
+      10                                                   |
+      11                                                   |
+      ^12                                                   |
+      [No Name] [+]                                        |
+      :quit                                                |
+    ]])
+  end)
+
+  -- oldtest: Test_splitkeep_fold()
+  it('does not scroll when window has closed folds', function()
+    exec([[
+      set splitkeep=screen
+      set foldmethod=marker
+      set number
+      let line = 1
+      for n in range(1, &lines)
+        call setline(line, ['int FuncName() {/*{{{*/', 1, 2, 3, 4, 5, '}/*}}}*/',
+              \ 'after fold'])
+        let line += 8
+      endfor
+    ]])
+    feed('L:wincmd s<CR>')
+    screen:expect([[
+        1 +--  7 lines: int FuncName() {···················|
+        8 after fold                                       |
+        9 +--  7 lines: int FuncName() {···················|
+       16 after fold                                       |
+       17 +--  7 lines: int FuncName() {···················|
+       24 ^after fold                                       |
+      [No Name] [+]                                        |
+       32 after fold                                       |
+       33 +--  7 lines: int FuncName() {···················|
+       40 after fold                                       |
+       41 +--  7 lines: int FuncName() {···················|
+       48 after fold                                       |
+      [No Name] [+]                                        |
+      :wincmd s                                            |
+    ]])
+    feed(':quit<CR>')
+    screen:expect([[
+        1 +--  7 lines: int FuncName() {···················|
+        8 after fold                                       |
+        9 +--  7 lines: int FuncName() {···················|
+       16 after fold                                       |
+       17 +--  7 lines: int FuncName() {···················|
+       24 after fold                                       |
+       25 +--  7 lines: int FuncName() {···················|
+       32 after fold                                       |
+       33 +--  7 lines: int FuncName() {···················|
+       40 after fold                                       |
+       41 +--  7 lines: int FuncName() {···················|
+       48 after fold                                       |
+       49 ^+--  7 lines: int FuncName() {···················|
+      :quit                                                |
+    ]])
+    feed('H:below split<CR>')
+    screen:expect([[
+        1 +--  7 lines: int FuncName() {···················|
+        8 after fold                                       |
+        9 +--  7 lines: int FuncName() {···················|
+       16 after fold                                       |
+       17 +--  7 lines: int FuncName() {···················|
+      [No Name] [+]                                        |
+       25 ^+--  7 lines: int FuncName() {···················|
+       32 after fold                                       |
+       33 +--  7 lines: int FuncName() {···················|
+       40 after fold                                       |
+       41 +--  7 lines: int FuncName() {···················|
+       48 after fold                                       |
+      [No Name] [+]                                        |
+      :below split                                         |
+    ]])
+    feed(':wincmd k<CR>:quit<CR>')
+    screen:expect([[
+        1 +--  7 lines: int FuncName() {···················|
+        8 after fold                                       |
+        9 +--  7 lines: int FuncName() {···················|
+       16 after fold                                       |
+       17 +--  7 lines: int FuncName() {···················|
+       24 after fold                                       |
+       25 ^+--  7 lines: int FuncName() {···················|
+       32 after fold                                       |
+       33 +--  7 lines: int FuncName() {···················|
+       40 after fold                                       |
+       41 +--  7 lines: int FuncName() {···················|
+       48 after fold                                       |
+       49 +--  7 lines: int FuncName() {···················|
+      :quit                                                |
+    ]])
+  end)
+end)