fix(folds): cursorline highlight is not always applied on closed folds

Problem:    The cursorline highlight logic checks for `w_cursor.lnum`
            which may be different from the line number passed to
            `win_line()` even when the cursor is actually on that line.
Solution:   Update cursor line highlight logic to check for the line
            number of the start of a closed fold if necessary.

src/nvim/buffer_defs.h

@@ -1112,20 +1112,23 @@ struct window_S {
  win_T *w_prev; ///< link to previous window
  win_T *w_next; ///< link to next window
  bool w_closing; ///< window is being closed, don't let
- ///  autocommands close it too.
+ ///< autocommands close it too.
 
  frame_T *w_frame; ///< frame containing this window
 
  pos_T w_cursor; ///< cursor position in buffer
 
  colnr_T w_curswant; ///< Column we want to be at. This is
- ///  used to try to stay in the same column
- ///  for up/down cursor motions.
+ ///< used to try to stay in the same column
+ ///< for up/down cursor motions.
 
  int w_set_curswant; // If set, then update w_curswant the next
  // time through cursupdate() to the
  // current virtual column
 
+ linenr_T w_cursorline; ///< Where 'cursorline' should be drawn,
+ ///< can be different from w_cursor.lnum
+ ///< for closed folds.
  linenr_T w_last_cursorline; ///< where last 'cursorline' was drawn
  pos_T w_last_cursormoved; ///< for CursorMoved event
 

src/nvim/drawline.c

@@ -303,7 +303,7 @@ static int draw_virt_text_item(buf_T *buf, int col, VirtText vt, HlMode hl_mode,
 static bool use_cursor_line_sign(win_T *wp, linenr_T lnum)
 {
  return wp->w_p_cul
- && lnum == wp->w_cursor.lnum
+ && lnum == wp->w_cursorline
  && (wp->w_p_culopt_flags & CULOPT_NBR);
 }
 
@@ -517,7 +517,7 @@ static void get_statuscol_display_info(statuscol_T *stcp, LineDrawState *draw_st
 static bool use_cursor_line_nr(win_T *wp, linenr_T lnum, int row, int startrow, int filler_lines)
 {
  return wp->w_p_cul
- && lnum == wp->w_cursor.lnum
+ && lnum == wp->w_cursorline
  && (wp->w_p_culopt_flags & CULOPT_NBR)
  && (row == startrow + filler_lines
  || (row > startrow + filler_lines
@@ -547,6 +547,12 @@ static inline void get_line_number_str(win_T *wp, linenr_T lnum, char *buf, size
 
 static int get_line_number_attr(win_T *wp, linenr_T lnum, int row, int startrow, int filler_lines)
 {
+ if (use_cursor_line_nr(wp, lnum, row, startrow, filler_lines)) {
+ // TODO(vim): Can we use CursorLine instead of CursorLineNr
+ // when CursorLineNr isn't set?
+ return win_hl_attr(wp, HLF_CLN);
+ }
+
  if (wp->w_p_rnu) {
  if (lnum < wp->w_cursor.lnum) {
  // Use LineNrAbove
@@ -558,12 +564,6 @@ static int get_line_number_attr(win_T *wp, linenr_T lnum, int row, int startrow,
  }
  }
 
- if (use_cursor_line_nr(wp, lnum, row, startrow, filler_lines)) {
- // TODO(vim): Can we use CursorLine instead of CursorLineNr
- // when CursorLineNr isn't set?
- return win_hl_attr(wp, HLF_CLN);
- }
-
  return win_hl_attr(wp, HLF_N);
 }
 
@@ -960,20 +960,17 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
  filler_todo = filler_lines;
 
  // Cursor line highlighting for 'cursorline' in the current window.
- if (lnum == wp->w_cursor.lnum) {
- // Do not show the cursor line in the text when Visual mode is active,
- // because it's not clear what is selected then.
- if (wp->w_p_cul && !(wp == curwin && VIsual_active)
- && wp->w_p_culopt_flags != CULOPT_NBR) {
- cul_screenline = (wp->w_p_wrap
- && (wp->w_p_culopt_flags & CULOPT_SCRLINE));
- if (!cul_screenline) {
- apply_cursorline_highlight(wp, lnum, &line_attr, &cul_attr, &line_attr_lowprio);
- } else {
- margin_columns_win(wp, &left_curline_col, &right_curline_col);
- }
- area_highlighting = true;
+ if (wp->w_p_cul && wp->w_p_culopt_flags != CULOPT_NBR && lnum == wp->w_cursorline
+ // Do not show the cursor line in the text when Visual mode is active,
+ // because it's not clear what is selected then.
+ && !(wp == curwin && VIsual_active)) {
+ cul_screenline = (wp->w_p_wrap && (wp->w_p_culopt_flags & CULOPT_SCRLINE));
+ if (!cul_screenline) {
+ apply_cursorline_highlight(wp, lnum, &line_attr, &cul_attr, &line_attr_lowprio);
+ } else {
+ margin_columns_win(wp, &left_curline_col, &right_curline_col);
  }
+ area_highlighting = true;
  }
 
  SignTextAttrs sattrs[SIGN_SHOW_MAX]; // sign attributes for the sign column

src/nvim/drawscreen.c

@@ -1548,7 +1548,15 @@ static void win_update(win_T *wp, DecorProviders *providers)
  wp->w_old_visual_col = 0;
  }
 
- bool cursorline_standout = win_cursorline_standout(wp);
+ foldinfo_T cursorline_fi;
+ wp->w_cursorline = win_cursorline_standout(wp) ? wp->w_cursor.lnum : 0;
+ if (wp->w_p_cul) {
+ // Make sure that the cursorline on a closed fold is redrawn
+ cursorline_fi = fold_info(wp, wp->w_cursor.lnum);
+ if (cursorline_fi.fi_level > 0 && cursorline_fi.fi_lines > 0) {
+ wp->w_cursorline = cursorline_fi.fi_lnum;
+ }
+ }
 
  win_check_ns_hl(wp);
 
@@ -1604,7 +1612,7 @@ static void win_update(win_T *wp, DecorProviders *providers)
  // if lines were inserted or deleted
  || (wp->w_match_head != NULL
  && buf->b_mod_xlines != 0)))))
- || (cursorline_standout && lnum == wp->w_cursor.lnum)
+ || lnum == wp->w_cursorline
  || lnum == wp->w_last_cursorline) {
  if (lnum == mod_top) {
  top_to_mod = false;
@@ -1755,7 +1763,8 @@ static void win_update(win_T *wp, DecorProviders *providers)
  // When lines are folded, display one line for all of them.
  // Otherwise, display normally (can be several display lines when
  // 'wrap' is on).
- foldinfo_T foldinfo = fold_info(wp, lnum);
+ foldinfo_T foldinfo = wp->w_p_cul && lnum == wp->w_cursor.lnum ?
+ cursorline_fi : fold_info(wp, lnum);
 
  if (foldinfo.fi_lines == 0
  && idx < wp->w_lines_valid
@@ -1814,7 +1823,8 @@ static void win_update(win_T *wp, DecorProviders *providers)
  if (wp->w_p_rnu && wp->w_last_cursor_lnum_rnu != wp->w_cursor.lnum) {
  // 'relativenumber' set and cursor moved vertically: The
  // text doesn't need to be drawn, but the number column does.
- foldinfo_T info = fold_info(wp, lnum);
+ foldinfo_T info = wp->w_p_cul && lnum == wp->w_cursor.lnum ?
+ cursorline_fi : fold_info(wp, lnum);
  (void)win_line(wp, lnum, srow, wp->w_grid.rows, true, true,
  info, &line_providers, &provider_err);
  }
@@ -1849,7 +1859,7 @@ static void win_update(win_T *wp, DecorProviders *providers)
 
  // Now that the window has been redrawn with the old and new cursor line,
  // update w_last_cursorline.
- wp->w_last_cursorline = cursorline_standout ? wp->w_cursor.lnum : 0;
+ wp->w_last_cursorline = wp->w_cursorline;
 
  wp->w_last_cursor_lnum_rnu = wp->w_p_rnu ? wp->w_cursor.lnum : 0;
 

test/functional/ui/fold_spec.lua

@@ -10,6 +10,7 @@ local meths = helpers.meths
 local exec = helpers.exec
 local exec_lua = helpers.exec_lua
 local assert_alive = helpers.assert_alive
+local poke_eventloop = helpers.poke_eventloop
 
 
 local content1 = [[
@@ -90,10 +91,10 @@ describe("folded lines", function()
  end)
 
  it("highlights with CursorLineFold when 'cursorline' is set", function()
- command("set cursorline foldcolumn=2 foldmethod=marker")
+ command("set number cursorline foldcolumn=2")
  command("hi link CursorLineFold Search")
  insert(content1)
- feed("zf3j")
+ feed("ggzf3jj")
  if multigrid then
  screen:expect([[
  ## grid 1
@@ -106,26 +107,26 @@ describe("folded lines", function()
  [2:---------------------------------------------]|
  [3:---------------------------------------------]|
  ## grid 2
- {7: }This is a |
- {7: }valid English  |
- {7: }sentence composed by |
- {7: }an exhausted developer |
- {7: }in his cave. |
- {6: }{12:^ }|
+ {7:+ }{8: 1 }{5:+-- 4 lines: This is a················}|
+ {6: }{9: 5 }{12:^in his cave.  }|
+ {7: }{8: 6 }  |
+ {1:~   }|
+ {1:~   }|
+ {1:~  }|
  {1:~ }|
  ## grid 3
  |
  ]])
  else
  screen:expect([[
- {7: }This is a |
- {7: }valid English  |
- {7: }sentence composed by |
- {7: }an exhausted developer |
- {7: }in his cave. |
- {6: }{12:^ }|
- {1:~ }|
- |
+  {7:+ }{8: 1 }{5:+-- 4 lines: This is a················}|
+  {6: }{9: 5 }{12:^in his cave.  }|
+  {7: }{8: 6 }  |
+  {1:~   }|
+  {1:~   }|
+  {1:~  }|
+  {1:~ }|
+  |
  ]])
  end
  feed("k")
@@ -141,28 +142,36 @@ describe("folded lines", function()
  [2:---------------------------------------------]|
  [3:---------------------------------------------]|
  ## grid 2
- {7: }This is a |
- {7: }valid English  |
- {7: }sentence composed by |
- {7: }an exhausted developer |
- {6: }{12:^in his cave. }|
- {7: }  |
+ {6:+ }{9: 1 }{12:^+-- 4 lines: This is a················}|
+ {7: }{8: 5 }in his cave. |
+ {7: }{8: 6 }  |
+ {1:~   }|
+ {1:~  }|
+ {1:~  }|
  {1:~ }|
  ## grid 3
  |
  ]])
  else
  screen:expect([[
- {7: }This is a |
- {7: }valid English  |
- {7: }sentence composed by |
- {7: }an exhausted developer |
- {6: }{12:^in his cave. }|
- {7: }  |
- {1:~ }|
- |
+  {6:+ }{9: 1 }{12:^+-- 4 lines: This is a················}|
+  {7: }{8: 5 }in his cave. |
+  {7: }{8: 6 }  |
+  {1:~   }|
+  {1:~  }|
+  {1:~  }|
+  {1:~ }|
+  |
  ]])
  end
+ -- CursorLine is applied correctly with screenrow motions #22232
+ feed("jgk")
+ poke_eventloop()
+ screen:expect_unchanged()
+ -- CursorLine is applied correctly when closing a fold when cursor is not at fold start
+ feed("zo4Gzc")
+ poke_eventloop()
+ screen:expect_unchanged()
  command("set cursorlineopt=line")
  if multigrid then
  screen:expect([[
@@ -176,26 +185,61 @@ describe("folded lines", function()
  [2:---------------------------------------------]|
  [3:---------------------------------------------]|
  ## grid 2
- {7: }This is a |
- {7: }valid English  |
- {7: }sentence composed by |
- {7: }an exhausted developer |
- {7: }{12:^in his cave. }|
- {7: }  |
+ {7:+ }{8: 1 }{12:^+-- 4 lines: This is a················}|
+ {7: }{8: 5 }in his cave. |
+ {7: }{8: 6 }  |
+ {1:~   }|
+ {1:~  }|
+ {1:~  }|
  {1:~ }|
  ## grid 3
  |
  ]])
  else
  screen:expect([[
- {7: }This is a |
- {7: }valid English |
- {7: }sentence composed by |
- {7: }an exhausted developer |
- {7: }{12:^in his cave. }|
- {7: } |
- {1:~ }|
- |
+ {7:+ }{8: 1 }{12:^+-- 4 lines: This is a················}|
+ {7: }{8: 5 }in his cave. |
+ {7: }{8: 6 } |
+ {1:~ }|
+ {1:~ }|
+ {1:~ }|
+ {1:~ }|
+ |
+ ]])
+ end
+ command("set relativenumber cursorlineopt=number")
+ if multigrid then
+ screen:expect([[
+ ## grid 1
+ [2:---------------------------------------------]|
+ [2:---------------------------------------------]|
+ [2:---------------------------------------------]|
+ [2:---------------------------------------------]|
+ [2:---------------------------------------------]|
+ [2:---------------------------------------------]|
+ [2:---------------------------------------------]|
+ [3:---------------------------------------------]|
+ ## grid 2
+ {6:+ }{9:1 }{5:^+-- 4 lines: This is a················}|
+ {7: }{8: 1 }in his cave. |
+ {7: }{8: 2 } |
+ {1:~ }|
+ {1:~ }|
+ {1:~ }|
+ {1:~ }|
+ ## grid 3
+ |
+ ]])
+ else
+ screen:expect([[
+ {6:+ }{9:1 }{5:^+-- 4 lines: This is a················}|
+ {7: }{8: 1 }in his cave. |
+ {7: }{8: 2 } |
+ {1:~ }|
+ {1:~ }|
+ {1:~ }|
+ {1:~ }|
+ |
  ]])
  end
  end)