From 24bd638356075cb7f59d6cb78b118588a6a18490 Mon Sep 17 00:00:00 2001
From: Tung Nguyen <tungtn3@gmail.com>
Date: Fri, 1 Apr 2016 15:15:50 +1100
Subject: [PATCH] Use rn2() instead of Rand() for selection_do_randline()

That is, use NetHack's RNG instead of the direct system RNG.  This fixes
maps generated with randlines to interact correctly with potential
future RNG system changes e.g. switching PRNG algorithms, supporting
NAO343's RNG reseeding, and even supporting replays like NetHack 4.

Based on DynaHack commit e464f63 (lev_comp: Fix system RNG use in
randline) by me.
---
 src/sp_lev.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/sp_lev.c b/src/sp_lev.c
index 30476bb39..c4c7f3765 100644
--- a/src/sp_lev.c
+++ b/src/sp_lev.c
@@ -4089,8 +4089,8 @@ struct opvar *ov;
         my = ((y1 + y2) / 2);
     } else {
         do {
-            dx = (Rand() % rough) - (rough / 2);
-            dy = (Rand() % rough) - (rough / 2);
+            dx = rn2(rough) - (rough / 2);
+            dy = rn2(rough) - (rough / 2);
             mx = ((x1 + x2) / 2) + dx;
             my = ((y1 + y2) / 2) + dy;
         } while ((mx > COLNO - 1 || mx < 0 || my < 0 || my > ROWNO - 1));