From 5191a11d66b925561b5f705aa42759a0e2a5624a Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Sat, 14 Sep 2024 19:28:13 +0800
Subject: [PATCH] vim-patch:9.1.0730: Crash with cursor-screenline and narrow
 window

Problem:  Crash with cursor-screenline and narrow window
          (elig0n)
Solution: Don't set right_col when width2 is 0 (zeertzjq).

fixes: vim/vim#15677
closes: vim/vim#15678

https://github.com/vim/vim/commit/59149f02692804267e7cc0665d0334f6ff4675be
---
 src/nvim/drawline.c                  |  2 +-
 test/old/testdir/test_cursorline.vim | 14 ++++++++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/nvim/drawline.c b/src/nvim/drawline.c
index c85b9d2288..3b88dd2e90 100644
--- a/src/nvim/drawline.c
+++ b/src/nvim/drawline.c
@@ -189,7 +189,7 @@ static void margin_columns_win(win_T *wp, int *left_col, int *right_col)
   *left_col = 0;
   *right_col = width1;
 
-  if (wp->w_virtcol >= (colnr_T)width1) {
+  if (wp->w_virtcol >= (colnr_T)width1 && width2 > 0) {
     *right_col = width1 + ((wp->w_virtcol - width1) / width2 + 1) * width2;
   }
   if (wp->w_virtcol >= (colnr_T)width1 && width2 > 0) {
diff --git a/test/old/testdir/test_cursorline.vim b/test/old/testdir/test_cursorline.vim
index d9c77c0b36..2c375f20c0 100644
--- a/test/old/testdir/test_cursorline.vim
+++ b/test/old/testdir/test_cursorline.vim
@@ -300,7 +300,7 @@ func Test_cursorline_screenline_update()
       set cursorline cursorlineopt=screenline
       inoremap <F2> <Cmd>call cursor(1, 1)<CR>
   END
-  call writefile(lines, 'Xcul_screenline')
+  call writefile(lines, 'Xcul_screenline', 'D')
 
   let buf = RunVimInTerminal('-S Xcul_screenline', #{rows: 8})
   call term_sendkeys(buf, "A")
@@ -310,7 +310,17 @@ func Test_cursorline_screenline_update()
   call term_sendkeys(buf, "\<Esc>")
 
   call StopVimInTerminal(buf)
-  call delete('Xcul_screenline')
+endfunc
+
+func Test_cursorline_screenline_zero_width()
+  CheckOption foldcolumn
+
+  set cursorline culopt=screenline winminwidth=1 foldcolumn=1
+  " This used to crash Vim
+  1vnew | redraw
+
+  bwipe!
+  set cursorline& culopt& winminwidth& foldcolumn&
 endfunc
 
 func Test_cursorline_cursorbind_horizontal_scroll()