From 41cc4427792a7b42f95d66ecd6526ee9c590c8fe Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Sun, 22 Dec 2019 09:47:58 -0700
Subject: [PATCH] fix extraction of numbers into a 64-bit value on 32-bit
 platforms

---
 racket/src/racket/src/bignum.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/racket/src/racket/src/bignum.c b/racket/src/racket/src/bignum.c
index 1c93bbd92a..88b9662923 100644
--- a/racket/src/racket/src/bignum.c
+++ b/racket/src/racket/src/bignum.c
@@ -380,7 +380,8 @@ int scheme_bignum_get_long_long_val(const Scheme_Object *o, mzlonglong *v)
   } else if (SCHEME_BIGLEN(o) == 0) {
     *v = 0;
     return 1;
-  } else if (SCHEME_BIGDIG(o)[MAX_BN_SIZE_FOR_LL - 1] == FIRST_BIT_MASK_LL 
+  } else if ((SCHEME_BIGLEN(o) == MAX_BN_SIZE_FOR_LL)
+             && SCHEME_BIGDIG(o)[MAX_BN_SIZE_FOR_LL - 1] == FIRST_BIT_MASK_LL 
 # if !defined(USE_LONG_LONG_FOR_BIGDIG) && !defined(SIXTY_FOUR_BIT_INTEGERS)
 	     && !SCHEME_BIGDIG(o)[0]
 # endif
@@ -391,7 +392,8 @@ int scheme_bignum_get_long_long_val(const Scheme_Object *o, mzlonglong *v)
     v2 = ((umzlonglong)v2 << 63);
     *v = v2;
     return 1;
-  } else if ((SCHEME_BIGDIG(o)[MAX_BN_SIZE_FOR_LL - 1] & FIRST_BIT_MASK_LL) != 0) { /* Won't fit into a signed long long */
+  } else if ((SCHEME_BIGLEN(o) == MAX_BN_SIZE_FOR_LL)
+             && ((SCHEME_BIGDIG(o)[MAX_BN_SIZE_FOR_LL - 1] & FIRST_BIT_MASK_LL) != 0)) { /* Won't fit into a signed long long */
     return 0;
   } else {
     mzlonglong v2;