From 8c9b57fadd3829f663c447ba8597f3fedbaa87fc Mon Sep 17 00:00:00 2001
From: Manuel Serrano <Manuel.Serrano@inria.fr>
Date: Thu, 12 Dec 2024 10:17:17 +0100
Subject: [PATCH] Fix generic bignums overflow (bootstrap)

---
 runtime/Clib/cbignum.c               | 7 ++++---
 runtime/Unsafe/bignumber-generic.sch | 8 ++++++--
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/runtime/Clib/cbignum.c b/runtime/Clib/cbignum.c
index ebf55d2d..581c561a 100644
--- a/runtime/Clib/cbignum.c
+++ b/runtime/Clib/cbignum.c
@@ -3,7 +3,7 @@
 /*    -------------------------------------------------------------    */
 /*    Author      :  José Romildo Malaquias                           */
 /*    Creation    :  Fri Nov 10 11:51:17 2006                          */
-/*    Last change :  Fri Nov 15 07:36:49 2024 (serrano)                */
+/*    Last change :  Thu Dec 12 09:52:45 2024 (serrano)                */
 /*    Copyright   :  2003-24 Manuel Serrano                            */
 /*    -------------------------------------------------------------    */
 /*    C implementation of bignum                                       */
@@ -846,10 +846,11 @@ obj_t
 bgl_safe_bignum_to_fixnum(obj_t bx) {
    size_t bs = mpz_sizeinbase(&(BIGNUM(bx).mpz), 2);
 
-   if (bs < BGL_INT_BIT_SIZE)
+   if (bs < BGL_INT_BIT_SIZE) {
       return BINT(bgl_bignum_to_long(bx));
-   else
+   } else {
       return bx;
+   }
 }
 
 /*---------------------------------------------------------------------*/
diff --git a/runtime/Unsafe/bignumber-generic.sch b/runtime/Unsafe/bignumber-generic.sch
index e7e947f0..77e7e928 100644
--- a/runtime/Unsafe/bignumber-generic.sch
+++ b/runtime/Unsafe/bignumber-generic.sch
@@ -3,7 +3,7 @@
 ;*    -------------------------------------------------------------    */
 ;*    Author      :  Manuel Serrano                                    */
 ;*    Creation    :  Thu Aug 29 07:41:07 2024                          */
-;*    Last change :  Thu Dec 12 08:48:41 2024 (serrano)                */
+;*    Last change :  Thu Dec 12 10:10:18 2024 (serrano)                */
 ;*    Copyright   :  2024 Manuel Serrano                               */
 ;*    -------------------------------------------------------------    */
 ;*    Portable implementation of bignums. This is used only when no    */
@@ -454,7 +454,11 @@
 ;*---------------------------------------------------------------------*/
 ;*    Overflow operations ...                                          */
 ;*---------------------------------------------------------------------*/
-(define ($bignum->fixnum-safe x) (or ($bignum->fixnum x) x))
+(define ($bignum->fixnum-safe x)
+   (let ((n ($bignum->fixnum x)))
+      (if (and n (=bx (fixnum->bignum n) x))
+	  n
+	  x)))
 (define ($+fx-safe x y) (+fx/ov x y))
 (define ($-fx-safe x y) (-fx/ov x y))
 (define ($*fx-safe x y) (*fx/ov x y))