Problems with mpz_set_str and huge strings

[Stefan Krah]

Torbjorn Granlund <tg at gmplib.org> wrote:
>   > I think your operands should be made to work, since they actually can be
>   > made to fit into memory.
>   
>   It appears to be an overflow in mpz/set_str.c, where xsize is ultimately
>   negative (printf inserted by me):
>   
>   Breakpoint 3, __gmpz_set_str (x=0xffe034ec, str=0xf7d6d2c2 "", base=10) at set_str.c:126
>   126     printf("str_size: %u  __mp_bases[]: %f  numb_bits+2: %d\n",
>   (gdb) n
>   str_size: 677741241  __mp_bases[]: 0.301030  numb_bits+2: 34
>   129       xsize = (((mp_size_t) (str_size / __mp_bases[base].chars_per_bit_exactly))
>   (gdb) p 677741241 / 0.301030
>   $1 = 2251407637.1125803
>   (gdb) p (long) (677741241 / 0.301030)
>   $2 = -2043559659
>   (gdb) n
>   131       MPZ_REALLOC (x, xsize);
>   (gdb) p xsize
>   $3 = -67108862
>   
> Thanks!  I changed the code there, and in 3 more places with similar
> code.  The new code should not overflow, I think.
>   
> The code is available here: http://shell.gmplib.org:8000/gmp-4.3/  

Great! I tested it and it works fine.

Stefan Krah