From 0d79c408fa1afd89eec80fbc9f3912368cb9898b Mon Sep 17 00:00:00 2001
From: Pignotto <77069478+Pignotto@users.noreply.github.com>
Date: Sun, 22 Jan 2023 00:30:17 +0100
Subject: [PATCH] binomial_distribution: mitigate undocumented behaviour

In param_type::_M_initialize(): Change integer literal to corresponding floating-point literal in multiplication by _M_t to avoid unsigned overflow and consequent chain of unpredicted behaviour
---
 libstdc++-v3/include/bits/random.tcc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/bits/random.tcc b/libstdc++-v3/include/bits/random.tcc
index f092b5cd4cbcd..2cf7377a4fcb9 100644
--- a/libstdc++-v3/include/bits/random.tcc
+++ b/libstdc++-v3/include/bits/random.tcc
@@ -1500,7 +1500,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  // sqrt(pi / 2)
 	  const double __spi_2 = 1.2533141373155002512078826424055226L;
 	  _M_s1 = std::sqrt(__np * __1p) * (1 + _M_d1 / (4 * __np));
-	  _M_s2 = std::sqrt(__np * __1p) * (1 + _M_d2 / (4 * _M_t * __1p));
+	  _M_s2 = std::sqrt(__np * __1p) * (1 + _M_d2 / (4. * _M_t * __1p));
 	  _M_c = 2 * _M_d1 / __np;
 	  _M_a1 = std::exp(_M_c) * _M_s1 * __spi_2;
 	  const double __a12 = _M_a1 + _M_s2 * __spi_2;