From 36c98b47a3526dc61d149f951f8b8e3a677c26eb Mon Sep 17 00:00:00 2001
From: Luuk van Baal <luukvbaal@gmail.com>
Date: Wed, 26 Apr 2023 22:15:25 +0200
Subject: vim-patch:9.0.0707: with 'smoothscroll' cursor position not adjusted
 in long line

Problem:    With 'smoothscroll' and 'scrolloff' non-zero the cursor position
            is not properly adjusted in a long line.
Solution:   Move the cursor further up or down in the line.

https://github.com/vim/vim/commit/118c235112854f34182d968613d7fe98be3b290b

Co-authored-by: Bram Moolenaar <Bram@vim.org>
---
 src/nvim/move.c                            | 29 ++++++++++++++-------
 test/functional/legacy/scroll_opt_spec.lua | 42 ++++++++++++++++++++++++++++++
 test/old/testdir/test_scroll_opt.vim       | 22 ++++++++++++++++
 3 files changed, 83 insertions(+), 10 deletions(-)

diff --git a/src/nvim/move.c b/src/nvim/move.c
index 144384c294..e7f5959dbb 100644
--- a/src/nvim/move.c
+++ b/src/nvim/move.c
@@ -1210,20 +1210,24 @@ bool scrolldown(long line_count, int byfold)
   }
 
   if (curwin->w_cursor.lnum == curwin->w_topline && do_sms) {
+    long so = curwin->w_p_so >= 0 ? curwin->w_p_so : p_so;
+    long scrolloff_cols = so == 0 ? 0 : width1 + (so - 1) * width2;
+
     // make sure the cursor is in the visible text
     validate_virtcol();
-    int col = curwin->w_virtcol - curwin->w_skipcol;
+    long col = curwin->w_virtcol - curwin->w_skipcol + scrolloff_cols;
     int row = 0;
     if (col >= width1) {
       col -= width1;
-      ++row;
+      row++;
     }
     if (col > width2) {
-      row += col / width2;
+      row += (int)col / width2;
       col = col % width2;
     }
     if (row >= curwin->w_height) {
-      coladvance(curwin->w_virtcol - (row - curwin->w_height + 1) * width2);
+      curwin->w_curswant = curwin->w_virtcol - (row - curwin->w_height + 1) * width2;
+      coladvance(curwin->w_curswant);
     }
   }
   return moved;
@@ -1329,20 +1333,25 @@ bool scrollup(long line_count, int byfold)
   }
 
   if (curwin->w_cursor.lnum == curwin->w_topline && do_sms && curwin->w_skipcol > 0) {
-    // make sure the cursor is in a visible part of the line
+    int width1 = curwin->w_width - curwin_col_off();
+    int width2 = width1 + curwin_col_off2();
+    long so = curwin->w_p_so >= 0 ? curwin->w_p_so : p_so;
+    long scrolloff_cols = so == 0 ? 0 : width1 + (so - 1) * width2;
+
+    // Make sure the cursor is in a visible part of the line, taking
+    // 'scrolloff' into account, but using screen lines.
     validate_virtcol();
-    if (curwin->w_virtcol < curwin->w_skipcol + 3) {
-      int width1 = curwin->w_width - curwin_col_off();
-      int width2 = width1 + curwin_col_off2();
+    if (curwin->w_virtcol < curwin->w_skipcol + 3 + scrolloff_cols) {
       colnr_T col = curwin->w_virtcol;
 
       if (col < width1) {
         col += width1;
       }
-      while (col < curwin->w_skipcol + 3) {
+      while (col < curwin->w_skipcol + 3 + scrolloff_cols) {
         col += width2;
       }
-      coladvance(col);
+      curwin->w_curswant = col;
+      coladvance(curwin->w_curswant);
     }
   }
 
diff --git a/test/functional/legacy/scroll_opt_spec.lua b/test/functional/legacy/scroll_opt_spec.lua
index 5c7c9cd55a..be7d324908 100644
--- a/test/functional/legacy/scroll_opt_spec.lua
+++ b/test/functional/legacy/scroll_opt_spec.lua
@@ -395,5 +395,47 @@ describe('smoothscroll', function()
       f text wi^th lots of text with lots of te|
                                               |
     ]])
+    -- 'scrolloff' set to 1, scrolling up, cursor moves screen line down
+    exec('set scrolloff=1')
+    feed('10|<C-E>')
+    screen:expect([[
+      <<<th lots of text with lots of text wit|
+      h lots of^ text with lots of text with lo|
+      ts of text with lots of text with lots o|
+      f text with lots of text with lots of te|
+      xt with lots of text with lots of text w|
+                                              |
+    ]])
+    -- 'scrolloff' set to 1, scrolling down, cursor moves screen line up
+    feed('<C-E>gjgj<C-Y>')
+    screen:expect([[
+      <<<th lots of text with lots of text wit|
+      h lots of text with lots of text with lo|
+      ts of text with lots of text with lots o|
+      f text wi^th lots of text with lots of te|
+      xt with lots of text with lots of text w|
+                                              |
+    ]])
+    -- 'scrolloff' set to 2, scrolling up, cursor moves screen line down
+    exec('set scrolloff=2')
+    feed('10|<C-E>')
+    screen:expect([[
+      <<<th lots of text with lots of text wit|
+      h lots of text with lots of text with lo|
+      ts of tex^t with lots of text with lots o|
+      f text with lots of text with lots of te|
+      xt with lots of text with lots of text w|
+                                              |
+    ]])
+    -- 'scrolloff' set to 2, scrolling down, cursor moves screen line up
+    feed('<C-E>gjgj<C-Y>')
+    screen:expect([[
+      <<<of text with lots of text with lots o|
+      f text with lots of text with lots of te|
+      xt with l^ots of text with lots of text w|
+      ith lots of text with lots of text with |
+      lots of text with lots of text with lots|
+                                              |
+    ]])
   end)
 end)
diff --git a/test/old/testdir/test_scroll_opt.vim b/test/old/testdir/test_scroll_opt.vim
index 0041fbaa25..3317ec9209 100644
--- a/test/old/testdir/test_scroll_opt.vim
+++ b/test/old/testdir/test_scroll_opt.vim
@@ -240,6 +240,28 @@ func Test_smoothscroll_wrap_long_line()
   call term_sendkeys(buf, "\<C-Y>")
   call VerifyScreenDump(buf, 'Test_smooth_long_5', {})
 
+  " 'scrolloff' set to 1, scrolling up, cursor moves screen line down
+  call term_sendkeys(buf, ":set scrolloff=1\<CR>")
+  call term_sendkeys(buf, "10|\<C-E>")
+  call VerifyScreenDump(buf, 'Test_smooth_long_6', {})
+  
+  " 'scrolloff' set to 1, scrolling down, cursor moves screen line up
+  call term_sendkeys(buf, "\<C-E>")
+  call term_sendkeys(buf, "gjgj")
+  call term_sendkeys(buf, "\<C-Y>")
+  call VerifyScreenDump(buf, 'Test_smooth_long_7', {})
+  
+  " 'scrolloff' set to 2, scrolling up, cursor moves screen line down
+  call term_sendkeys(buf, ":set scrolloff=2\<CR>")
+  call term_sendkeys(buf, "10|\<C-E>")
+  call VerifyScreenDump(buf, 'Test_smooth_long_8', {})
+  
+  " 'scrolloff' set to 2, scrolling down, cursor moves screen line up
+  call term_sendkeys(buf, "\<C-E>")
+  call term_sendkeys(buf, "gj")
+  call term_sendkeys(buf, "\<C-Y>")
+  call VerifyScreenDump(buf, 'Test_smooth_long_9', {})
+  
   call StopVimInTerminal(buf)
 endfunc
 
-- 
cgit