From 49d28f2204dfbb21156d98b0313399c8126b59e0 Mon Sep 17 00:00:00 2001
From: Simon Tatham <anakin@pobox.com>
Date: Thu, 21 Oct 2021 20:39:09 +0100
Subject: [PATCH] Tents: fix bias in tent placement.

In the very first stage of game generation, we're supposed to pick 1/5
of the grid squares to put tents in, in a uniformly random manner. It
failed to be uniform, because I had the wrong limit in random_upto -
but it was too small rather than too large, so it never overran the
buffer in a way that something like ASan or valgrind would have caught.
---
 tents.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tents.c b/tents.c
index 5eb34b0..8b93653 100644
--- a/tents.c
+++ b/tents.c
@@ -998,7 +998,7 @@ static char *new_game_desc(const game_params *params_in, random_state *rs,
 	    int dy, dx;
             bool ok = true;
 
-            which = i + random_upto(rs, j);
+            which = i + random_upto(rs, w*h - i);
             tmp = order[which];
             order[which] = order[i];
             order[i] = tmp;