patch 9.1.0215: Half-page scrolling does not support smooth-scrollingv9.1.0215

Problem:  Page-wise scrolling with Ctrl-D/Ctrl-U implements
          it's own logic to change the topline and cursor.
          More logic than necessary for scrolling with Ctrl-F/Ctrl-B
          was removed in patch 9.1.0211.
Solution: Re-use the logic from Ctrl-E/Ctrl-Y/Ctrl-F/Ctrl-B while
          staying backward compatible as much as possible.
          Restore some of the logic that determined how many lines will
          be scrolled (Luuk van Baal)

closes: #14316

Signed-off-by: Luuk van Baal <luukvbaal@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

4 files changed, 65 insertions, 36 deletions

diff --git a/src/testdir/dumps/Test_cursorline_redraw_2.dump b/src/testdir/dumps/Test_cursorline_redraw_2.dump
index 323bef8e2c..d1b4e4e17c 100644
--- a/src/testdir/dumps/Test_cursorline_redraw_2.dump
+++ b/src/testdir/dumps/Test_cursorline_redraw_2.dump
@@ -1,20 +1,20 @@
-| +0&#ffffff0@39
-|T|h|e| |{|o|p|t|i|o|n|}| |a|r|g|u|m|e|n|t|s| |t|o| |"|:|s|e|t|"| |m|a|y| |b|e| 
+|T+0&#ffffff0|h|e| |{|o|p|t|i|o|n|}| |a|r|g|u|m|e|n|t|s| |t|o| |"|:|s|e|t|"| |m|a|y| |b|e| 
 |r|e|p|e|a|t|e|d|.| @1|F|o|r| |e|x|a|m|p|l|e|:| |>| @14
-| +8&&@7>:|s|e|t| |a|i| |n|o|s|i| |s|w|=|3| |t|s|=|3| @9
-|I+0&&|f| |y|o|u| |m|a|k|e| |a|n| |e|r@1|o|r| |i|n| |o|n|e| |o|f| |t|h|e| |a|r|g|u|m
+@8|:|s|e|t| |a|i| |n|o|s|i| |s|w|=|3| |t|s|=|3| @9
+|I|f| |y|o|u| |m|a|k|e| |a|n| |e|r@1|o|r| |i|n| |o|n|e| |o|f| |t|h|e| |a|r|g|u|m
 |e|n|t|s|,| |a|n| |e|r@1|o|r| |m|e|s@1|a|g|e| |w|i|l@1| |b|e| |g|i|v|e|n| @3
 |a|n|d| |t|h|e| |f|o|l@1|o|w|i|n|g| |a|r|g|u|m|e|n|t|s| |w|i|l@1| |b|e| |i|g|n|o
 |r|e|d|.| @35
 @40
 @40
 @16|*|:|s|e|t|-|v|e|r|b|o|s|e|*| @9
-|W|h|e|n| |'|v|e|r|b|o|s|e|'| |i|s| |n|o|n|-|z|e|r|o|,| |d|i|s|p|l|a|y|i|n|g| |a
+>W+8&&|h|e|n| |'|v|e|r|b|o|s|e|'| |i|s| |n|o|n|-|z|e|r|o|,| |d|i|s|p|l|a|y|i|n|g| |a
 |n| |o|p|t|i|o|n| |v|a|l|u|e| |w|i|l@1| |a|l|s|o| |t|e|l@1| |w|h|e|r|e| |i|t| @1
-|w|a|s| |l|a|s|t| |s|e|t|.| @1|E|x|a|m|p|l|e|:| |>| @14
+|w+0&&|a|s| |l|a|s|t| |s|e|t|.| @1|E|x|a|m|p|l|e|:| |>| @14
 @8|:|v|e|r|b|o|s|e| |s|e|t| |s|h|i|f|t|w|i|d|t|h| |c|i|n|d|e|n|t|?
 |<| @1|s|h|i|f|t|w|i|d|t|h|=|4| |~| @22
 @10|L|a|s|t| |s|e|t| |f|r|o|m| |m|o|d|e|l|i|n|e| |l|i|n|e| |1| 
 |~| @38
 @2|c|i|n|d|e|n|t| |~| @28
-@22|7|,|2|-|9| @8|4@1|%| 
+|@+0#4040ff13&@2| @36
+| +0#0000000&@21|1|2|,|1| @9|5|0|%| 
diff --git a/src/testdir/test_edit.vim b/src/testdir/test_edit.vim
index c81c244537..fbe7b9ba19 100644
--- a/src/testdir/test_edit.vim
+++ b/src/testdir/test_edit.vim
@@ -1294,15 +1294,15 @@ func Test_edit_PAGEUP_PAGEDOWN()
   call feedkeys("i\<PageDown>\<esc>", 'tnix')
   call assert_equal([0, 30, 1, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 30, 1, 0], getpos('.'))
+  call assert_equal([0, 29, 1, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 23, 1, 0], getpos('.'))
+  call assert_equal([0, 21, 1, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 15, 1, 0], getpos('.'))
+  call assert_equal([0, 13, 1, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
   call assert_equal([0, 10, 1, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 10, 11, 0], getpos('.'))
+  call assert_equal([0, 2, 11, 0], getpos('.'))
   " <S-Up> is the same as <PageUp>
   " <S-Down> is the same as <PageDown>
   call cursor(1, 1)
@@ -1317,28 +1317,28 @@ func Test_edit_PAGEUP_PAGEDOWN()
   call feedkeys("i\<S-Down>\<esc>", 'tnix')
   call assert_equal([0, 30, 1, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 30, 1, 0], getpos('.'))
+  call assert_equal([0, 29, 1, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 23, 1, 0], getpos('.'))
+  call assert_equal([0, 21, 1, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 15, 1, 0], getpos('.'))
+  call assert_equal([0, 13, 1, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
   call assert_equal([0, 10, 1, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 10, 11, 0], getpos('.'))
+  call assert_equal([0, 2, 11, 0], getpos('.'))
   set nostartofline
   call cursor(30, 11)
   norm! zt
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 30, 11, 0], getpos('.'))
+  call assert_equal([0, 29, 11, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 23, 11, 0], getpos('.'))
+  call assert_equal([0, 21, 11, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 15, 11, 0], getpos('.'))
+  call assert_equal([0, 13, 11, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
   call assert_equal([0, 10, 11, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 10, 11, 0], getpos('.'))
+  call assert_equal([0, 2, 11, 0], getpos('.'))
   call cursor(1, 1)
   call feedkeys("A\<PageDown>\<esc>", 'tnix')
   call assert_equal([0, 9, 11, 0], getpos('.'))
@@ -1355,15 +1355,15 @@ func Test_edit_PAGEUP_PAGEDOWN()
   call cursor(30, 11)
   norm! zt
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 30, 11, 0], getpos('.'))
+  call assert_equal([0, 29, 11, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 23, 11, 0], getpos('.'))
+  call assert_equal([0, 21, 11, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 15, 11, 0], getpos('.'))
+  call assert_equal([0, 13, 11, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
   call assert_equal([0, 10, 11, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 10, 11, 0], getpos('.'))
+  call assert_equal([0, 2, 11, 0], getpos('.'))
   call cursor(1, 1)
   call feedkeys("A\<S-Down>\<esc>", 'tnix')
   call assert_equal([0, 9, 11, 0], getpos('.'))
diff --git a/src/testdir/test_normal.vim b/src/testdir/test_normal.vim
index dd2f2be2f9..3a7248fd08 100644
--- a/src/testdir/test_normal.vim
+++ b/src/testdir/test_normal.vim
@@ -1280,9 +1280,13 @@ func Test_vert_scroll_cmds()
   exe "normal \<C-D>"
   call assert_equal(46, line('.'))
   exe "normal \<C-U>"
-  call assert_equal(36, line('.'))
+  call assert_equal(36, line('w0'))
+  call assert_equal(46, line('.'))
   exe "normal \<C-U>"
-  call assert_equal(10, line('.'))
+  call assert_equal(1,  line('w0'))
+  call assert_equal(40, line('.'))
+  exe "normal \<C-U>"
+  call assert_equal(30, line('.'))
   exe "normal \<C-U>"
   call assert_equal(1, line('.'))
   set scroll&
@@ -1303,9 +1307,8 @@ func Test_vert_scroll_cmds()
   call assert_equal(50, line('.'))
   call assert_equal(100, line('w$'))
   normal z.
-  let lnum = winline()
   exe "normal \<C-D>"
-  call assert_equal(lnum, winline())
+  call assert_equal(1, winline())
   call assert_equal(50, line('.'))
   normal zt
   exe "normal \<C-D>"
@@ -3066,7 +3069,8 @@ func Test_normal42_halfpage()
   call assert_equal(2, &scroll)
   set scroll=5
   exe "norm! \<c-u>"
-  call assert_equal('3', getline('.'))
+  call assert_equal('3', getline('w0'))
+  call assert_equal('8', getline('.'))
   1
   set scrolloff=5
   exe "norm! \<c-d>"
@@ -3813,11 +3817,11 @@ func Test_normal_vert_scroll_longline()
   call assert_equal(11, line('.'))
   call assert_equal(1, winline())
   exe "normal \<C-B>"
-  call assert_equal(11, line('.'))
-  call assert_equal(9, winline())
+  call assert_equal(10, line('.'))
+  call assert_equal(10, winline())
   exe "normal \<C-B>\<C-B>"
   call assert_equal(5, line('.'))
-  call assert_equal(1, winline())
+  call assert_equal(5, winline())
 
   bwipe!
 endfunc
@@ -4186,12 +4190,16 @@ func Test_single_line_scroll()
   norm! {
   call assert_equal([0, 1, 1, 0], getpos('.'))
 
-  " Ctrl-B scrolls up with hidden "above" virtual text.
+  " Ctrl-B/Ctrl-U scroll up with hidden "above" virtual text.
   set smoothscroll
   exe "normal \<C-E>"
   call assert_notequal(0, winsaveview().skipcol)
   exe "normal \<C-B>"
   call assert_equal(0, winsaveview().skipcol)
+  exe "normal \<C-E>"
+  call assert_notequal(0, winsaveview().skipcol)
+  exe "normal \<C-U>"
+  call assert_equal(0, winsaveview().skipcol)
 
   set smoothscroll&
   bw!
diff --git a/src/testdir/test_scroll_opt.vim b/src/testdir/test_scroll_opt.vim
index 24804956f4..788870f876 100644
--- a/src/testdir/test_scroll_opt.vim
+++ b/src/testdir/test_scroll_opt.vim
@@ -1005,18 +1005,39 @@ func Test_smoothscroll_page()
   call setline(1, 'abcde '->repeat(150))
 
   exe "norm! \<C-F>"
-  call assert_equal(320, winsaveview().skipcol)
+  call assert_equal(400, winsaveview().skipcol)
   exe "norm! \<C-F>"
-  call assert_equal(640, winsaveview().skipcol)
+  call assert_equal(800, winsaveview().skipcol)
   exe "norm! \<C-F>"
   call assert_equal(880, winsaveview().skipcol)
   exe "norm! \<C-B>"
-  call assert_equal(560, winsaveview().skipcol)
+  call assert_equal(480, winsaveview().skipcol)
   exe "norm! \<C-B>"
-  call assert_equal(240, winsaveview().skipcol)
+  call assert_equal(80, winsaveview().skipcol)
   exe "norm! \<C-B>"
   call assert_equal(0, winsaveview().skipcol)
 
+  exe "norm! \<C-D>"
+  call assert_equal(200, winsaveview().skipcol)
+  exe "norm! \<C-D>"
+  call assert_equal(400, winsaveview().skipcol)
+  exe "norm! \<C-D>"
+  call assert_equal(600, winsaveview().skipcol)
+  exe "norm! \<C-D>"
+  call assert_equal(800, winsaveview().skipcol)
+  exe "norm! \<C-D>"
+  call assert_equal(880, winsaveview().skipcol)
+  exe "norm! \<C-U>"
+  call assert_equal(680, winsaveview().skipcol)
+  exe "norm! \<C-U>"
+  call assert_equal(480, winsaveview().skipcol)
+  exe "norm! \<C-U>"
+  call assert_equal(280, winsaveview().skipcol)
+  exe "norm! \<C-U>"
+  call assert_equal(80, winsaveview().skipcol)
+  exe "norm! \<C-U>"
+  call assert_equal(0, winsaveview().skipcol)
+
   set smoothscroll&
 endfunc