From: Eli Zaretskii <eliz@gnu.org>
Date: Sat, 14 Aug 2021 14:39:38 +0000 (+0300)
Subject: Fix 'random' on MS-Windows when integers are wider than 30 bits
X-Git-Tag: emacs-28.0.90~1506
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=482049e54277f0a429efdcd660286e9e7b465033;p=emacs.git

Fix 'random' on MS-Windows when integers are wider than 30 bits

* src/w32.c (random): Provide more random bits for MS-Windows
builds with EMACS_INT that is wider than 32 bits.  (Bug#32605)
---

diff --git a/src/w32.c b/src/w32.c
index 968b4bbe489..180c73aa0f0 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -2389,8 +2389,13 @@ rand_as183 (void)
 int
 random (void)
 {
-  /* rand_as183 () gives us 15 random bits...hack together 30 bits.  */
+  /* rand_as183 () gives us 15 random bits...hack together 30 bits for
+     Emacs with 32-bit EMACS_INT, and at least 31 bit for wider EMACS_INT.  */
+#if EMACS_INT_MAX > INT_MAX
+  return ((rand_as183 () << 30) | (rand_as183 () << 15) | rand_as183 ());
+#else
   return ((rand_as183 () << 15) | rand_as183 ());
+#endif
 }
 
 void