patch 9.0.0672: line partly shows with 'smoothscroll' and 'scrolloff' zero

Problem:    Cursor line only partly shows with 'smoothscroll' and 'scrolloff'
            zero.
Solution:   Do not use 'smoothscroll' when adjusting the bottom of the window.
            (closes #11269)
diff --git a/src/move.c b/src/move.c
index e79ed72..77f5cb9 100644
--- a/src/move.c
+++ b/src/move.c
@@ -2171,6 +2171,7 @@
 {
     int		used;
     int		scrolled = 0;
+    int		min_scrolled = 1;
     int		extra = 0;
     int		i;
     linenr_T	line_count;
@@ -2236,6 +2237,10 @@
 	scrolled = used;
 	if (cln == curwin->w_botline)
 	    scrolled -= curwin->w_empty_rows;
+	min_scrolled = scrolled;
+	if (cln > curwin->w_botline && curwin->w_p_sms && curwin->w_p_wrap)
+	    for (linenr_T lnum = curwin->w_botline + 1; lnum <= cln; ++lnum)
+		min_scrolled += plines_nofill(lnum);
     }
 
     /*
@@ -2361,7 +2366,12 @@
     if (line_count >= curwin->w_height && line_count > min_scroll)
 	scroll_cursor_halfway(FALSE);
     else
+    {
+	// With 'smoothscroll' scroll at least the height of the cursor line.
+	if (curwin->w_p_wrap && curwin->w_p_sms && line_count < min_scrolled)
+	    line_count = min_scrolled;
 	scrollup(line_count, TRUE);
+    }
 
     /*
      * If topline didn't change we need to restore w_botline and w_empty_rows