vim-patch:9.1.0171: Small split-move related improvements

Problem:  small improvements can be made to split-move related
          functions.
Solution: apply them (Sean Dewar):

Some of these changes were already applied to Nvim.
Here are the ones which were missing:

- Improve some doc comments (frame_flatten should still work for non-current
  tabpages, despite the topframe check, which looks benign, though I'm unsure if
  it's still needed; see vim/vim#2467).

- f_win_splitmove should check_split_disallowed on wp, not targetwin, as that's
  what win_splitmove checks (though it's probably unnecessary to check
  b_locked_split at all; see vim/vim#14109, which I hope to get around to
  finishing at some point).

- Apply the winframe_restore comment changes, and remove win_comp_pos from after
  winframe_restore in win_splitmove, as it shouldn't be necessary (no need to
  remove it from nvim_win_set_config too, as it was already omitted).
  Move win_append after winframe_restore in win_splitmove to match Vim.

closes: vim/vim#14185

vim/vim@5cac1a9

src/nvim/eval/window.c

@@ -701,8 +701,8 @@ void f_win_splitmove(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
  size = (int)tv_dict_get_number(d, "size");
  }
 
- // Check if we can split the target before we bother switching windows.
- if (is_aucmd_win(wp) || text_or_buf_locked() || check_split_disallowed(targetwin) == FAIL) {
+ // Check if we're allowed to continue before we bother switching windows.
+ if (is_aucmd_win(wp) || text_or_buf_locked() || check_split_disallowed(wp) == FAIL) {
  return;
  }
 

src/nvim/window.c

@@ -939,7 +939,7 @@ void ui_ext_win_viewport(win_T *wp)
  }
 }
 
-/// If "split_disallowed" is set or "wp"s buffer is closing, give an error and return FAIL.
+/// If "split_disallowed" is set, or "wp"'s buffer is closing, give an error and return FAIL.
 /// Otherwise return OK.
 int check_split_disallowed(const win_T *wp)
  FUNC_ATTR_NONNULL_ALL
@@ -1966,13 +1966,12 @@ int win_splitmove(win_T *wp, int size, int flags)
 
  // Split a window on the desired side and put "wp" there.
  if (win_split_ins(size, flags, wp, dir, unflat_altfr) == NULL) {
- win_append(wp->w_prev, wp, NULL);
  if (!wp->w_floating) {
  // win_split_ins doesn't change sizes or layout if it fails to insert an
  // existing window, so just undo winframe_remove.
  winframe_restore(wp, dir, unflat_altfr);
- win_comp_pos(); // recompute window positions
  }
+ win_append(wp->w_prev, wp, NULL);
  return FAIL;
  }
 
@@ -3271,7 +3270,6 @@ win_T *winframe_find_altwin(win_T *win, int *dirp, tabpage_T *tp, frame_T **altf
 /// Flatten "frp" into its parent frame if it's the only child, also merging its
 /// list with the grandparent if they share the same layout.
 /// Frees "frp" if flattened; also "frp->fr_parent" if it has the same layout.
-/// "frp" must be valid in the current tabpage.
 static void frame_flatten(frame_T *frp)
  FUNC_ATTR_NONNULL_ALL
 {
@@ -3359,7 +3357,8 @@ void winframe_restore(win_T *wp, int dir, frame_T *unflat_altfr)
  int row = wp->w_winrow;
  int col = wp->w_wincol;
 
- // Restore the lost room that was redistributed to the altframe.
+ // Restore the lost room that was redistributed to the altframe. Also
+ // adjusts window sizes to fit restored statuslines/separators, if needed.
  if (dir == 'v') {
  frame_new_height(unflat_altfr, unflat_altfr->fr_height - frp->fr_height,
  unflat_altfr == frp->fr_next, false);

test/old/testdir/test_window_cmd.vim

@@ -200,6 +200,20 @@ func Test_window_split_edit_bufnr()
  %bw!
 endfunc
 
+func s:win_layout_info() abort
+ return #{
+ \ layout: winlayout(),
+ \ pos_sizes: range(1, winnr('$'))
+ \  ->map({_, nr -> win_getid(nr)->getwininfo()[0]})
+ \  ->map({_, wininfo -> #{id: wininfo.winid,
+ \  row: wininfo.winrow,
+ \  col: wininfo.wincol,
+ \  width: wininfo.width,
+ \  height: wininfo.height}})
+ \  ->sort({a, b -> a.id - b.id})
+ \ }
+endfunc
+
 func Test_window_split_no_room()
  " N horizontal windows need >= 2*N + 1 lines:
  " - 1 line + 1 status line in each window
@@ -216,12 +230,10 @@ func Test_window_split_no_room()
 
  botright vsplit
  wincmd |
- let layout = winlayout()
- let restcmd = winrestcmd()
+ let info = s:win_layout_info()
  call assert_fails('wincmd J', 'E36:')
  call assert_fails('wincmd K', 'E36:')
- call assert_equal(layout, winlayout())
- call assert_equal(restcmd, winrestcmd())
+ call assert_equal(info, s:win_layout_info())
  only
 
  " N vertical windows need >= 2*(N - 1) + 1 columns:
@@ -238,30 +250,28 @@ func Test_window_split_no_room()
 
  split
  wincmd |
- let layout = winlayout()
- let restcmd = winrestcmd()
+ let info = s:win_layout_info()
  call assert_fails('wincmd H', 'E36:')
  call assert_fails('wincmd L', 'E36:')
- call assert_equal(layout, winlayout())
- call assert_equal(restcmd, winrestcmd())
+ call assert_equal(info, s:win_layout_info())
 
  " Check that the last statusline isn't lost.
  " Set its window's width to 2 for the test.
  wincmd j
  set laststatus=0 winminwidth=0
  vertical resize 2
+ " Update expected positions/sizes after the resize. Layout is unchanged.
+ let info.pos_sizes = s:win_layout_info().pos_sizes
  set winminwidth&
  call setwinvar(winnr('k'), '&statusline', '@#')
  let last_stl_row = win_screenpos(0)[0] - 1
  redraw
  call assert_equal('@#|', GetScreenStr(last_stl_row))
  call assert_equal('~ |', GetScreenStr(&lines - &cmdheight))
 
- let restcmd = winrestcmd()
  call assert_fails('wincmd H', 'E36:')
  call assert_fails('wincmd L', 'E36:')
- call assert_equal(layout, winlayout())
- call assert_equal(restcmd, winrestcmd())
+ call assert_equal(info, s:win_layout_info())
  call setwinvar(winnr('k'), '&statusline', '=-')
  redraw
  call assert_equal('=-|', GetScreenStr(last_stl_row))
@@ -1076,6 +1086,7 @@ func Test_win_splitmove()
  augroup WinSplitMove
  au!
  au WinEnter * ++once let s:triggered = v:true
+ \| call assert_fails('call win_splitmove(winnr(), winnr("$"))', 'E242:')
  \| call assert_fails('call win_splitmove(winnr("$"), winnr())', 'E242:')
  augroup END
  quit
@@ -1086,7 +1097,7 @@ func Test_win_splitmove()
  augroup WinSplitMove
  au!
  au BufHidden * ++once let s:triggered = v:true
- \| call assert_fails('call win_splitmove(winnr("#"), winnr())', 'E1159:')
+ \| call assert_fails('call win_splitmove(winnr(), winnr("#"))', 'E1159:')
  augroup END
  hide
  call assert_equal(v:true, s:triggered)
@@ -2088,13 +2099,11 @@ func Test_autocmd_window_force_room()
  au BufEnter * ++once let s:triggered = v:true
  \| call assert_equal('autocmd', win_gettype())
  augroup END
- let layout = winlayout()
- let restcmd = winrestcmd()
+ let info = s:win_layout_info()
  " bufload opening the autocommand window shouldn't give E36.
  call bufload('unload me')
  call assert_equal(v:true, s:triggered)
- call assert_equal(winlayout(), layout)
- call assert_equal(winrestcmd(), restcmd)
+ call assert_equal(info, s:win_layout_info())
 
  unlet! s:triggered
  au! AucmdWinForceRoom