Commit: patch 9.2.0887: scroll: jump-scrolling when moving the cursor onto a wrapping line

[Christian Brabandt]

patch 9.2.0887: scroll: jump-scrolling when moving the cursor onto a wrapping line

Commit: https://github.com/vim/vim/commit/d0b42a50b7da1cd443df02df45b1faf9c6691262
Author: Hirohito Higashi <h.eas...@gmail.com>
Date: Fri Jul 31 18:58:18 2026 +0000

patch 9.2.0887: scroll: jump-scrolling when moving the cursor onto a wrapping line

Problem: With 'smoothscroll' and "lastline" in 'display', moving the cursor
to a wrapping line scrolls much more than needed.
Solution: Only require the screen lines up to the cursor to be visible, the
rest of the line can be cut off at the bottom.

closes: #20895

Co-Authored-By: Claude Opus 5 (1M context) <nor...@anthropic.com>
Signed-off-by: Hirohito Higashi <h.eas...@gmail.com>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/runtime/doc/todo.txt b/runtime/doc/todo.txt
index a8073702f..6329ac24a 100644
--- a/runtime/doc/todo.txt
+++ b/runtime/doc/todo.txt
@@ -64,9 +64,6 @@ Virtual text problems:
When 'virtualedit' is "all" and 'cursorcolumn' is set, the wrong column may be
highlighted. (van-de-bugger, 2018 Jan 23, #2576)

-With 'smoothscroll' set and "lastline" in 'display', moving the cursor to a
-wrapping line that makes the display scroll up may scroll much more than
-needed, thus jump-scrolling. (part of issue 12411)
Errors when running tests with valgrind:
- test_codestyle.vim: e.g.:
command line..script /home/mool/vim/vim91/src/testdir/runtest.vim[569]..function RunTheTest[52]..Test_test_files line 6: keycode_check.vim: space before tab: Expected 0 but got 7
diff --git a/src/move.c b/src/move.c
index cd9169de9..9b45b0e2b 100644
--- a/src/move.c
+++ b/src/move.c
@@ -2701,6 +2701,15 @@ scroll_cursor_bot(int min_scroll, int set_topbot)
used = curwin->w_cline_height;
#endif

+ if (do_sms && (dy_flags & DY_LASTLINE))
+ {
+ // The rest of the cursor line may be cut off at the bottom.
+ int upto_cursor = plines_win_col(curwin, cln, curwin->w_cursor.col);
+
+ if (upto_cursor < used)
+ used = upto_cursor;
+ }
+
// If the cursor is on or below botline, we will at least scroll by the
// height of the cursor line, which is "used". Correct for empty lines,
// which are really part of botline.
diff --git a/src/testdir/test_scroll_opt.vim b/src/testdir/test_scroll_opt.vim
index fc266da03..ee865e637 100644
--- a/src/testdir/test_scroll_opt.vim
+++ b/src/testdir/test_scroll_opt.vim
@@ -1370,6 +1370,26 @@ func Test_smoothscroll_squeezed_window()
bwipe!
endfunc

+func Test_smoothscroll_lastline_no_jump()
+ call NewWindow(10, 40)
+ setlocal smoothscroll
+ set display=lastline
+ call setline(1, map(range(1, 9), {i, v -> 'short ' .. v})
+ \ + [repeat('long ', 60)] + repeat(['tail'], 5))
+ normal! gg
+ redraw
+ call assert_equal(1, line('w0'))
+
+ " The first screen line of the wrapping line is already visible.
+ normal! 9j
+ redraw
+ call assert_equal(10, line('.'))
+ call assert_equal(1, line('w0'))
+
+ set display&
+ bwipe!
+endfunc
+
func Test_smoothscroll_long_line_zb()
call NewWindow(10, 40)
call setline(1, 'abcde '->repeat(150))
diff --git a/src/version.c b/src/version.c
index 59e9c7bb4..b3bd5174f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@ static char *(features[]) =

static int included_patches[] =
{ /* Add new patch number below this line */
+/**/
+ 887,
/**/
886,
/**/