fixup! feat(window/ui): add splitkeep option

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.
vim/vim@29ab524

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)
vim/vim@5ed3917

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.
vim/vim@470a141

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)
vim/vim@e697d48

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)
vim/vim@3735f11

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)
vim/vim@594f9e0

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)
vim/vim@d5bc762

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)
vim/vim@faf1d41

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)
vim/vim@20e5856

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)
vim/vim@7c1cbb6

vim-patch:9.0.0605: dump file missing

Problem:    Dump file missing.
Solution:   Add the missing dump file. (issue vim/vim#11234)
vim/vim@439a2ba

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)
vim/vim@13ece2a

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)
vim/vim@346823d

src/nvim/edit.c

@@ -2597,6 +2597,7 @@ int cursor_up(long n, int upd_topline)
   if (upd_topline) {
     update_topline(curwin);  // make sure curwin->w_topline is valid
   }
+
   return OK;
 }
 

src/nvim/globals.h

@@ -1071,10 +1071,11 @@ EXTERN char windowsVersion[20] INIT(= { 0 });
 
 EXTERN int exit_need_delay INIT(= 0);
 
-// Skip win_fix_cursor() call for 'splitkeep' when cmdwin is closed.
+///< Skip win_fix_cursor() call for 'splitkeep' when cmdwin is closed.
 EXTERN bool skip_win_fix_cursor INIT(= false);
-// Skip win_fix_scroll() call for 'splitkeep' when closing tab page.
+///< Skip win_fix_scroll() call for 'splitkeep' when closing tab page.
 EXTERN bool skip_win_fix_scroll INIT(= false);
-// Skip update_topline() call while executing win_fix_scroll().
+///< Skip update_topline() call while executing win_fix_scroll().
 EXTERN bool skip_update_topline INIT(= false);
+
 #endif  // NVIM_GLOBALS_H

src/nvim/option_defs.h

@@ -729,7 +729,7 @@ EXTERN unsigned int tpf_flags;  ///< flags from 'termpastefilter'
 EXTERN char *p_tfu;             ///< 'tagfunc'
 EXTERN char *p_spc;             ///< 'spellcapcheck'
 EXTERN char *p_spf;             ///< 'spellfile'
-EXTERN char *p_spk;             //   'splitkeep'
+EXTERN char *p_spk;             ///< 'splitkeep'
 EXTERN char *p_spl;             ///< 'spelllang'
 EXTERN char *p_spo;             // 'spelloptions'
 EXTERN unsigned int spo_flags;

src/nvim/optionstr.c

@@ -1097,7 +1097,7 @@ char *did_set_string_option(int opt_idx, char **varp, char *oldval, char *errbuf
       errmsg = e_invarg;
     }
   } else if (varp == &p_spk) {  // 'splitkeep'
-    if (check_opt_strings(p_spk, p_spk_values, true) != OK) {
+    if (check_opt_strings(p_spk, p_spk_values, false) != OK) {
       errmsg = e_invarg;
     }
   } else if (varp == &p_debug) {  // 'debug'

src/nvim/testdir/test_window_cmd.vim

@@ -1,5 +1,7 @@
 " Tests for window cmd (:wincmd, :split, :vsplit, :resize and etc...)
+
 source check.vim
+source screendump.vim
 
 func Test_window_cmd_ls0_with_split()
   set ls=0
@@ -1504,7 +1506,9 @@ func Test_splitkeep_options()
     let &laststatus = (run % 3)
     let &splitbelow = (run % 3)
     let &equalalways = (run % 2)
-    "let wsb = (run % 2) && &splitbelow
+    " Nvim: both windows have a winbar after splitting
+    " let wsb = (run % 2) && &splitbelow
+    let wsb = 0
     let tl = (gui ? 0 : ((run % 5) ? 1 : 0))
     let pos = !(run % 3) ? 'H' : ((run % 2) ? 'M' : 'L')
     tabnew | tabonly! | redraw
@@ -1526,51 +1530,51 @@ func Test_splitkeep_options()
     call assert_equal(1, line("w0"))
     call assert_equal(&scroll, winheight(0) / 2)
     wincmd j
-    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl - wsb, line("w0"))
 
     " No scroll when resizing windows
     wincmd k | resize +2 | redraw
     call assert_equal(1, line("w0"))
     wincmd j
-    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl - wsb, line("w0"))
 
     " No scroll when dragging statusline
     call win_move_statusline(1, -3)
-    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl - wsb, line("w0"))
     wincmd k
     call assert_equal(1, line("w0"))
 
     " No scroll when changing shellsize
     set lines+=2
     call assert_equal(1, line("w0"))
     wincmd j
-    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl - wsb, line("w0"))
     set lines-=2
-    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl - wsb, line("w0"))
     wincmd k
     call assert_equal(1, line("w0"))
 
     " No scroll when equalizing windows
     wincmd =
     call assert_equal(1, line("w0"))
     wincmd j
-    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl - wsb, line("w0"))
     wincmd k
     call assert_equal(1, line("w0"))
 
     " No scroll in windows split multiple times
     vsplit | split | 4wincmd w
-    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl - wsb, line("w0"))
     1wincmd w | quit | wincmd l | split
-    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl - wsb, line("w0"))
     wincmd j
-    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl - wsb, line("w0"))
 
     " No scroll in small window
     2wincmd w | only | 5split | wincmd k
     call assert_equal(1, line("w0"))
     wincmd j
-    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl - wsb, line("w0"))
 
     " No scroll for vertical split
     quit | vsplit | wincmd l
@@ -1580,7 +1584,7 @@ func Test_splitkeep_options()
 
     " No scroll in windows split and quit multiple times
     quit | redraw | split | split | quit | redraw
-    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 1 : win_screenpos(0)[0] - tl - wsb, line("w0"))
 
     " No scroll for new buffer
     1wincmd w | only | copen | wincmd k
@@ -1605,7 +1609,7 @@ func Test_splitkeep_options()
     only | execute "norm gg5\<C-e>" | split | wincmd k
     call assert_equal(6, line("w0"))
     wincmd j
-    call assert_equal(&spk == 'topline' ? 6 : 5 + win_screenpos(0)[0] - tl, line("w0"))
+    call assert_equal(&spk == 'topline' ? 6 : 5 + win_screenpos(0)[0] - tl - wsb, line("w0"))
   endfor
 
   tabnew | tabonly! | %bwipeout!

src/nvim/window.c

@@ -6081,12 +6081,12 @@ void set_fraction(win_T *wp)
   }
 }
 
-// Handle scroll position for 'splitkeep'.  Replaces scroll_to_fraction()
-// call from win_set_inner_size().  Instead we iterate over all windows in a
-// tabpage and calculate the new scroll position.
-// TODO(luukvbaal): Ensure this also works with wrapped lines.
-// Requires topline to be able to be set to a bufferline with some
-// offset(row-wise scrolling/smoothscroll).
+/// Handle scroll position for 'splitkeep'.  Replaces scroll_to_fraction()
+/// call from win_set_inner_size().  Instead we iterate over all windows in a
+/// tabpage and calculate the new scroll position.
+/// TODO(luukvbaal): Ensure this also works with wrapped lines.
+/// Requires topline to be able to be set to a bufferline with some
+/// offset(row-wise scrolling/smoothscroll).
 void win_fix_scroll(int resize)
 {
   linenr_T lnum;
@@ -6095,14 +6095,14 @@ void win_fix_scroll(int resize)
   FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
     // Skip when window height has not changed or when floating.
     if (!wp->w_floating && wp->w_height != wp->w_prev_height) {
-      // Determine botline needed to avoid scrolling and set cursor.
+      // If window has moved update botline to keep the same screenlines.
       if (*p_spk == 's' && wp->w_winrow != wp->w_prev_winrow
           && wp->w_botline - 1 <= wp->w_buffer->b_ml.ml_line_count) {
+        lnum = wp->w_cursor.lnum;
         int diff = (wp->w_winrow - wp->w_prev_winrow)
                    + (wp->w_height - wp->w_prev_height);
-        lnum = wp->w_cursor.lnum;
         wp->w_cursor.lnum = wp->w_botline - 1;
-        //  Add difference in height and row to botline.
+        // Add difference in height and row to botline.
         if (diff > 0) {
           cursor_down_inner(wp, diff);
         } else {
@@ -6131,9 +6131,9 @@ void win_fix_scroll(int resize)
   }
 }
 
-// Make sure the cursor position is valid for 'splitkeep'.
-// If it is not, put the cursor position in the jumplist and move it.
-// If we are not in normal mode, scroll to make valid instead.
+/// Make sure the cursor position is valid for 'splitkeep'.
+/// If it is not, put the cursor position in the jumplist and move it.
+/// If we are not in normal mode, scroll to make valid instead.
 static void win_fix_cursor(int normal)
 {
   win_T *wp = curwin;
@@ -6146,6 +6146,7 @@ static void win_fix_cursor(int normal)
     return;
   }
 
+  // Determine valid cursor range.
   so = MIN(wp->w_height_inner / 2, so);
   wp->w_cursor.lnum = wp->w_topline;
   linenr_T top = cursor_down_inner(wp, so);
@@ -6160,7 +6161,8 @@ static void win_fix_cursor(int normal)
   }
 
   if (nlnum) {  // Cursor is invalid for current scroll position.
-    if (normal) {  // Save to jumplist and set cursor to avoid scrolling.
+    if (normal) {
+      // Save to jumplist and set cursor to avoid scrolling.
       setmark('\'');
       wp->w_cursor.lnum = nlnum;
     } else {
@@ -6327,7 +6329,7 @@ void win_set_inner_size(win_T *wp, bool valid_cursor)
 
     // There is no point in adjusting the scroll position when exiting.  Some
     // values might be invalid.
-    if (!exiting && valid_cursor && *p_spk == 'c') {
+    if (valid_cursor && !exiting && *p_spk == 'c') {
       scroll_to_fraction(wp, prev_height);
     }
     redraw_later(wp, UPD_SOME_VALID);