From 3b6fb3fefd0bde9bd0700987c4db549a7f4916ec Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Sun, 25 Jun 2023 08:15:45 +0800
Subject: vim-patch:9.0.1664: divide by zero when scrolling with 'smoothscroll'
 set

Problem:    Divide by zero when scrolling with 'smoothscroll' set.
Solution:   Avoid using a negative width. (closes vim/vim#12540, closes vim/vim#12528)

https://github.com/vim/vim/commit/8154e642aa476e1a5d3de66c34e8289845b2b797

Co-authored-by: fullwaywang <fullwaywang@tencent.com>
---
 test/functional/legacy/scroll_opt_spec.lua | 42 ++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

(limited to 'test/functional')

diff --git a/test/functional/legacy/scroll_opt_spec.lua b/test/functional/legacy/scroll_opt_spec.lua
index 3b755ff3e8..165570e7ec 100644
--- a/test/functional/legacy/scroll_opt_spec.lua
+++ b/test/functional/legacy/scroll_opt_spec.lua
@@ -939,6 +939,48 @@ describe('smoothscroll', function()
     ]])
   end)
 
+  -- oldtest: Test_smoothscroll_zero_width_scroll_cursor_bot()
+  it('does not divide by zero in zero-width window', function()
+    screen:try_resize(12, 19)
+    screen:set_default_attr_ids({
+      [1] = {foreground = Screen.colors.Brown};  -- LineNr
+      [2] = {bold = true, reverse = true};  -- StatusLine
+      [3] = {reverse = true};  -- StatusLineNC
+    })
+    exec([[
+      silent normal yy
+      silent normal 19p
+      winsize 0 19
+      vsplit
+      vertical resize 0
+      set foldcolumn=1
+      set number
+      set smoothscroll
+      silent normal 20G
+    ]])
+    screen:expect([[
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1: }│          |
+      {1:^ }│          |
+      {2:< }{3:<ame] [+] }|
+                  |
+    ]])
+  end)
+
   it("works with virt_lines above and below", function()
     screen:try_resize(55, 7)
     exec([=[
-- 
cgit