Commit: patch 9.0.1981: not being able to scroll up in diff mode

[Christian Brabandt]

patch 9.0.1981: not being able to scroll up in diff mode

Commit: https://github.com/vim/vim/commit/0583491277dea9d14e000051c26405b90d839072
Author: zeertzjq <zeer...@outlook.com>
Date: Wed Oct 4 20:12:37 2023 +0200

patch 9.0.1981: not being able to scroll up in diff mode

Problem: Cannot scroll up in diff mode with many filler lines and zero
'scrolloff'.
Solution: Invalidate w_cline_row before calling comp_botline().

closes: #13256

Signed-off-by: Christian Brabandt <c...@256bit.org>
Co-authored-by: zeertzjq <zeer...@outlook.com>

diff --git a/src/move.c b/src/move.c
index ba1eadb9f..e5309df48 100644
--- a/src/move.c
+++ b/src/move.c
@@ -3262,6 +3262,7 @@ onepage(int dir, long count)
#ifdef FEAT_DIFF
curwin->w_topfill = 0;
#endif
+ curwin->w_valid &= ~(VALID_WROW|VALID_CROW);
}
comp_botline(curwin);
curwin->w_cursor.lnum = curwin->w_botline - 1;
diff --git a/src/testdir/test_diffmode.vim b/src/testdir/test_diffmode.vim
index cb042e115..e05d91601 100644
--- a/src/testdir/test_diffmode.vim
+++ b/src/testdir/test_diffmode.vim
@@ -1614,6 +1614,42 @@ func Test_diff_scroll_wrap_on()
call assert_equal(1, winsaveview().topline)
normal! j
call assert_equal(2, winsaveview().topline)
+
+ bwipe!
+ bwipe!
+endfunc
+
+func Test_diff_scroll_many_filler()
+ 20new
+ vnew
+ call setline(1, ['^^^', '^^^', '$$$', '$$$'])
+ diffthis
+ setlocal scrolloff=0
+ wincmd p
+ call setline(1, ['^^^', '^^^'] + repeat(['###'], 41) + ['$$$', '$$$'])
+ diffthis
+ setlocal scrolloff=0
+ wincmd p
+ redraw
+
+ " Note: need a redraw after each scroll, otherwise the test always passes.
+ normal! G
+ redraw
+ call assert_equal(3, winsaveview().topline)
+ call assert_equal(18, winsaveview().topfill)
+ exe "normal! \<C-B>"
+ redraw
+ call assert_equal(3, winsaveview().topline)
+ call assert_equal(19, winsaveview().topfill)
+ exe "normal! \<C-B>"
+ redraw
+ call assert_equal(2, winsaveview().topline)
+ call assert_equal(0, winsaveview().topfill)
+ exe "normal! \<C-B>"
+ redraw
+ call assert_equal(1, winsaveview().topline)
+ call assert_equal(0, winsaveview().topfill)
+
bwipe!
bwipe!
endfunc
diff --git a/src/version.c b/src/version.c
index d7b3c9bd3..15e87d62a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@ static char *(features[]) =

static int included_patches[] =
{ /* Add new patch number below this line */
+/**/
+ 1981,
/**/
1980,
/**/