vim-patch:8.2.0615: regexp benchmark stest is old style (#20940)

Problem:    Regexp benchmark stest is old style.
Solution:   Make it a new style test.  Fix using a NULL list.  Add more tests.
            (Yegappan Lakshmanan, closes vim/vim#5963)

https://github.com/vim/vim/commit/ad48e6c1590842ab6d48e6caba3e9250734dae27

N/A patches:
vim-patch:9.0.0829: wrong counts in macro comment

1 files changed, 8 insertions, 0 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index bc669a3e11..37da475e59 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -5581,6 +5581,13 @@ void set_buffer_lines(buf_T *buf, linenr_T lnum_arg, bool append, const typval_T
   const char *line = NULL;
   if (lines->v_type == VAR_LIST) {
     l = lines->vval.v_list;
+    if (l == NULL || tv_list_len(l) == 0) {
+      // set proper return code
+      if (lnum > curbuf->b_ml.ml_line_count) {
+        rettv->vval.v_number = 1;       // FAIL
+      }
+      goto done;
+    }
     li = tv_list_first(l);
   } else {
     line = tv_get_string_chk(lines);
@@ -5651,6 +5658,7 @@ void set_buffer_lines(buf_T *buf, linenr_T lnum_arg, bool append, const typval_T
     update_topline(curwin);
   }
 
+done:
   if (!is_curbuf) {
     curbuf = curbuf_save;
     curwin = curwin_save;