vim-patch:9.1.0211: page-wise scrolling does not support smooth-scrolling

Problem:  Page-wise scrolling with Ctrl-F/Ctrl-B implements
          it's own logic to change the topline and cursor.
          In doing so, skipcol is not handled properly for
          'smoothscroll', and virtual lines.
Solution: Re-use the logic from Ctrl-E/Ctrl-Y while staying
          backward compatible as much as possible.

https://github.com/vim/vim/commit/b9f5b95b7bec2414a5a96010514702d99afea18e

5 files changed, 86 insertions, 52 deletions

diff --git a/test/functional/legacy/scroll_opt_spec.lua b/test/functional/legacy/scroll_opt_spec.lua
index 78028f2f44..c00993f5f7 100644
--- a/test/functional/legacy/scroll_opt_spec.lua
+++ b/test/functional/legacy/scroll_opt_spec.lua
@@ -740,7 +740,7 @@ describe('smoothscroll', function()
                                               |
     ]])
     exec("call setline(92, 'a'->repeat(100))")
-    feed('<C-B>G')
+    feed('<C-L><C-B>G')
     -- cursor is not placed below window
     screen:expect([[
       {1:<<<}aaaaaaaaaaaaaaaaa                    |
diff --git a/test/old/testdir/test_diffmode.vim b/test/old/testdir/test_diffmode.vim
index c1a63a6f88..3e7eabf8f5 100644
--- a/test/old/testdir/test_diffmode.vim
+++ b/test/old/testdir/test_diffmode.vim
@@ -1632,34 +1632,38 @@ endfunc
 func Test_diff_scroll_many_filler()
   20new
   vnew
-  call setline(1, ['^^^', '^^^', '$$$', '$$$'])
+  call setline(1, range(1, 40))
   diffthis
   setlocal scrolloff=0
   wincmd p
-  call setline(1, ['^^^', '^^^'] + repeat(['###'], 41) + ['$$$', '$$$'])
+  call setline(1, range(1, 20)->reverse() + ['###']->repeat(41) + range(21, 40)->reverse())
   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)
+  for _ in range(2)
+    normal! G
+    redraw
+    call assert_equal(40, winsaveview().topline)
+    call assert_equal(19, winsaveview().topfill)
+    exe "normal! \<C-B>"
+    redraw
+    call assert_equal(22, winsaveview().topline)
+    call assert_equal(0, winsaveview().topfill)
+    exe "normal! \<C-B>"
+    redraw
+    call assert_equal(4, 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)
+    set smoothscroll
+  endfor
 
+  set smoothscroll&
   bwipe!
   bwipe!
 endfunc
diff --git a/test/old/testdir/test_edit.vim b/test/old/testdir/test_edit.vim
index 8281b3d495..2d4314a276 100644
--- a/test/old/testdir/test_edit.vim
+++ b/test/old/testdir/test_edit.vim
@@ -1312,15 +1312,15 @@ 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, 29, 1, 0], getpos('.'))
+  call assert_equal([0, 30, 1, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 21, 1, 0], getpos('.'))
+  call assert_equal([0, 23, 1, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 13, 1, 0], getpos('.'))
+  call assert_equal([0, 15, 1, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 5, 1, 0], getpos('.'))
+  call assert_equal([0, 10, 1, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 5, 11, 0], getpos('.'))
+  call assert_equal([0, 10, 11, 0], getpos('.'))
   " <S-Up> is the same as <PageUp>
   " <S-Down> is the same as <PageDown>
   call cursor(1, 1)
@@ -1335,28 +1335,28 @@ 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, 29, 1, 0], getpos('.'))
+  call assert_equal([0, 30, 1, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 21, 1, 0], getpos('.'))
+  call assert_equal([0, 23, 1, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 13, 1, 0], getpos('.'))
+  call assert_equal([0, 15, 1, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 5, 1, 0], getpos('.'))
+  call assert_equal([0, 10, 1, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 5, 11, 0], getpos('.'))
+  call assert_equal([0, 10, 11, 0], getpos('.'))
   set nostartofline
   call cursor(30, 11)
   norm! zt
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 29, 11, 0], getpos('.'))
+  call assert_equal([0, 30, 11, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 21, 11, 0], getpos('.'))
+  call assert_equal([0, 23, 11, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 13, 11, 0], getpos('.'))
+  call assert_equal([0, 15, 11, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 5, 11, 0], getpos('.'))
+  call assert_equal([0, 10, 11, 0], getpos('.'))
   call feedkeys("A\<PageUp>\<esc>", 'tnix')
-  call assert_equal([0, 5, 11, 0], getpos('.'))
+  call assert_equal([0, 10, 11, 0], getpos('.'))
   call cursor(1, 1)
   call feedkeys("A\<PageDown>\<esc>", 'tnix')
   call assert_equal([0, 9, 11, 0], getpos('.'))
@@ -1373,15 +1373,15 @@ func Test_edit_PAGEUP_PAGEDOWN()
   call cursor(30, 11)
   norm! zt
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 29, 11, 0], getpos('.'))
+  call assert_equal([0, 30, 11, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 21, 11, 0], getpos('.'))
+  call assert_equal([0, 23, 11, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 13, 11, 0], getpos('.'))
+  call assert_equal([0, 15, 11, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 5, 11, 0], getpos('.'))
+  call assert_equal([0, 10, 11, 0], getpos('.'))
   call feedkeys("A\<S-Up>\<esc>", 'tnix')
-  call assert_equal([0, 5, 11, 0], getpos('.'))
+  call assert_equal([0, 10, 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/test/old/testdir/test_normal.vim b/test/old/testdir/test_normal.vim
index d31ae488d9..644a632413 100644
--- a/test/old/testdir/test_normal.vim
+++ b/test/old/testdir/test_normal.vim
@@ -131,7 +131,7 @@ func Test_normal01_keymodel()
   call assert_equal([0, 1, 1, 0], getpos("'<"))
   call assert_equal([0, 3, 1, 0], getpos("'>"))
   call feedkeys("Gz\<CR>8|\<S-PageUp>y", 'xt')
-  call assert_equal([0, 2, 1, 0], getpos("'<"))
+  call assert_equal([0, 3, 1, 0], getpos("'<"))
   call assert_equal([0, 3, 8, 0], getpos("'>"))
   " Test for <S-C-Home> and <S-C-End>
   call cursor(2, 12)
@@ -915,12 +915,10 @@ func Test_normal14_page()
   set scrolloff=0
   100
   exe "norm! $\<c-b>"
-  call assert_equal('92', getline('.'))
   call assert_equal([0, 92, 1, 0, 1], getcurpos())
   100
   set nostartofline
   exe "norm! $\<c-b>"
-  call assert_equal('92', getline('.'))
   call assert_equal([0, 92, 2, 0, v:maxcol], getcurpos())
   " cleanup
   set startofline
@@ -3825,11 +3823,11 @@ func Test_normal_vert_scroll_longline()
   call assert_equal(11, line('.'))
   call assert_equal(1, winline())
   exe "normal \<C-B>"
-  call assert_equal(10, line('.'))
-  call assert_equal(3, winline())
+  call assert_equal(11, line('.'))
+  call assert_equal(9, winline())
   exe "normal \<C-B>\<C-B>"
   call assert_equal(5, line('.'))
-  call assert_equal(5, winline())
+  call assert_equal(1, winline())
 
   bwipe!
 endfunc
@@ -4182,20 +4180,30 @@ func Test_normal34_zet_large()
   norm! z9765405999999999999
 endfunc
 
-" Test for { and } paragraph movements in a single line
-func Test_brace_single_line()
-  let text =<< trim [DATA]
-    foobar one two three
-  [DATA]
+" Test for { and } paragraph movements and Ctrl-B in buffer with a single line
+func Test_single_line_scroll()
+  CheckFeature textprop
 
   new
-  call setline(1, text)
+  call setline(1, ['foobar one two three'])
+  let vt = 'virt_above'
+  call prop_type_add(vt, {'highlight': 'IncSearch'})
+  call prop_add(1, 0, {'type': vt, 'text': '---', 'text_align': 'above'})
   1
   norm! 0}
 
   call assert_equal([0, 1, 20, 0], getpos('.'))
   norm! {
   call assert_equal([0, 1, 1, 0], getpos('.'))
+
+  " Ctrl-B scrolls 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)
+
+  set smoothscroll&
   bw!
 endfunc
 
diff --git a/test/old/testdir/test_scroll_opt.vim b/test/old/testdir/test_scroll_opt.vim
index 8130f7a1ac..ebfed77214 100644
--- a/test/old/testdir/test_scroll_opt.vim
+++ b/test/old/testdir/test_scroll_opt.vim
@@ -832,7 +832,7 @@ func Test_smoothscroll_eob()
   call VerifyScreenDump(buf, 'Test_smooth_eob_1', {})
 
   " cursor is not placed below window
-  call term_sendkeys(buf, ":call setline(92, 'a'->repeat(100))\<CR>\<C-B>G")
+  call term_sendkeys(buf, ":call setline(92, 'a'->repeat(100))\<CR>\<C-L>\<C-B>G")
   call VerifyScreenDump(buf, 'Test_smooth_eob_2', {})
 
   call StopVimInTerminal(buf)
@@ -1001,4 +1001,26 @@ func Test_smoothscroll_textoff_small_winwidth()
   set smoothscroll& number&
 endfunc
 
+func Test_smoothscroll_page()
+  set smoothscroll
+
+  10split | 40vsplit
+  call setline(1, 'abcde '->repeat(150))
+
+  exe "norm! \<C-F>"
+  call assert_equal(320, winsaveview().skipcol)
+  exe "norm! \<C-F>"
+  call assert_equal(640, winsaveview().skipcol)
+  exe "norm! \<C-F>"
+  call assert_equal(880, winsaveview().skipcol)
+  exe "norm! \<C-B>"
+  call assert_equal(560, winsaveview().skipcol)
+  exe "norm! \<C-B>"
+  call assert_equal(240, winsaveview().skipcol)
+  exe "norm! \<C-B>"
+  call assert_equal(0, winsaveview().skipcol)
+
+  set smoothscroll&
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab