patch 9.1.0054: 'linebreak' may still apply to leading whitespace

Problem:  'linebreak' may still apply to leading whitespace
          (VanaIgr)
Solution: Compare pointers instead of virtual columns.
          (zeertzjq)

related: neovim/neovim#27180
closes: #13915

Co-authored-by: VanaIgr <vanaigranov@gmail.com>
Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_listlbr.vim b/src/testdir/test_listlbr.vim
index bcbd886..68bf948 100644
--- a/src/testdir/test_listlbr.vim
+++ b/src/testdir/test_listlbr.vim
@@ -374,13 +374,13 @@
 
 func Test_linebreak_no_break_after_whitespace_only()
   call s:test_windows('setl ts=4 linebreak wrap')
-  call setline(1, "\tabcdefghijklmnopqrstuvwxyz" ..
+  call setline(1, "\t  abcdefghijklmnopqrstuvwxyz" ..
         \ "abcdefghijklmnopqrstuvwxyz")
   let lines = s:screen_lines([1, 4], winwidth(0))
   let expect = [
-\ "    abcdefghijklmnop",
-\ "qrstuvwxyzabcdefghij",
-\ "klmnopqrstuvwxyz    ",
+\ "      abcdefghijklmn",
+\ "opqrstuvwxyzabcdefgh",
+\ "ijklmnopqrstuvwxyz  ",
 \ "~                   ",
 \ ]
   call s:compare_lines(expect, lines)