From 11b5c567124a61d8e8249a0fbcce47f2688573c6 Mon Sep 17 00:00:00 2001 From: Kaz Kylheku Date: Sat, 25 May 2019 22:03:54 -0700 Subject: bugfix: c_num won't convert most negative value. This bug causes a problem particularly in FFI. THe conversion of an integer to the FFI int type begins by conversion via c_num to the cnum type, which is at least as wide as int. Alas, the INT_MIN value (e.g. #x-80000000 on 32 bits) will not convert! Fixing this has a ripple effect. We alter the INT_PTR_MIN constant to include this value. This causes the derived NUM_MIN to also include the extra negative value, extending the fixnum range by one value. Everything seems to be okay. * configure: Decrease value of INT_PTR_MIN and DOUBLE_INTPTR_MIN constants by one to include the most negative two's complement value. * ffi.c (make_ffi_type_enum): We must not subtract 1 from INT_PTR_MIN here any more. * mpi.c (mp_in_range): If the bignum is negative, then extend the range check by one value, so that we don't reject the most negative two's complement value. --- mpi/mpi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'mpi/mpi.c') diff --git a/mpi/mpi.c b/mpi/mpi.c index 9ece8047..5befd2b3 100644 --- a/mpi/mpi.c +++ b/mpi/mpi.c @@ -463,8 +463,9 @@ int mp_in_range(mp_int *mp, uint_ptr_t lim, int unsig) { const unsigned ptrnd = (SIZEOF_PTR + MP_DIGIT_BIT - 1) / MP_DIGIT_BIT; mp_size nd = USED(mp); + int neg = ISNEG(mp); - if (unsig && ISNEG(mp)) + if (unsig && neg) return 0; if (nd < ptrnd) @@ -476,7 +477,7 @@ int mp_in_range(mp_int *mp, uint_ptr_t lim, int unsig) { mp_digit top = DIGITS(mp)[ptrnd - 1]; lim >>= ((ptrnd - 1) * MP_DIGIT_BIT); - return top <= lim; + return (top - neg) <= lim; } } -- cgit v1.2.3