Q:

In VIM, Change the number that relative lines numbers start from

I've turned on vim's relative line numbers, it starts from 0 but doing somthing like 10dd means I only get up to line 9, leaving the last one behind (becuase it's 10 including the current line). Yes, I know, It's only a super simple equation (10 + 1) but it's time taken up when I just want to check the number in the gutter and instantly get the number.
Is there a way to change the number the relative numbers start on? From 0 to 1? I've googled but I can't find anything and I did check out VIM's help page on the 'relativenumber' and 'number_relativenumber' sections but I couldn't see anything on it (or I probably missed it if it's there).
So is there any way to do this or is just not possible?

A:

Well, vim is open source.  If you clone it from:
git clone https://github.com/vim/vim.git

You can make the following changes to src/screen.c to do what you want:
diff --git a/src/screen.c b/src/screen.c
index 20a778a68..38d4368a9 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -2521,8 +2521,8 @@ fold_line(
        else
        {
        /* 'relativenumber', don't use negative numbers */
-       num = labs((long)get_cursor_rel_lnum(wp, lnum));
-       if (num == 0 && wp->w_p_nu && wp->w_p_rnu)
+       num = labs((long)get_cursor_rel_lnum(wp, lnum)) + 1;
+       if (num == 1 && wp->w_p_nu && wp->w_p_rnu)
        {
            /* 'number' + 'relativenumber': cursor line shows absolute
             * line number */
@@ -3745,8 +3745,8 @@ win_line(
            else
            {
                /* 'relativenumber', don't use negative numbers */
-               num = labs((long)get_cursor_rel_lnum(wp, lnum));
-               if (num == 0 && wp->w_p_nu && wp->w_p_rnu)
+               num = labs((long)get_cursor_rel_lnum(wp, lnum)) + 1;
+               if (num == 1 && wp->w_p_nu && wp->w_p_rnu)
                {
                /* 'number' + 'relativenumber' */
                num = lnum;

But sorry, examining the source confirms there's no existing option available to do what you want.

