tweak yet another possible overflow path

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@10138 57a11ea4-9604-0410-9ed3-97b8803252fd
This commit is contained in:
Linas Vepstas 2004-07-03 01:49:22 +00:00
parent 3e14e8c3d3
commit c1f9d93c9c

View File

@ -421,7 +421,7 @@ gnc_numeric_mul(gnc_numeric a, gnc_numeric b,
gint64 denom, gint how)
{
gnc_numeric product, result;
qofint128 bigprod;
qofint128 bignume, bigdeno;
if(gnc_numeric_check(a) || gnc_numeric_check(b)) {
return gnc_numeric_error(GNC_ERROR_ARG);
@ -453,19 +453,24 @@ gnc_numeric_mul(gnc_numeric a, gnc_numeric b,
b.denom = 1;
}
bigprod = mult128 (a.num, b.num);
bignume = mult128 (a.num, b.num);
bigdeno = mult128 (a.denom, b.denom);
product.num = a.num*b.num;
product.denom = a.denom*b.denom;
/* If it looks to be overflowing, try to reduce the fraction ... */
if (bigprod.isbig)
if (bignume.isbig || bigdeno.isbig)
{
/* If rounding allowed, then shift until there's no
* more overflow. The conversion at the end will fix
* things up for the final value. */
* things up for the final value. Else overflow. */
if ((how & GNC_NUMERIC_RND_MASK) == GNC_HOW_RND_NEVER)
{
product = reduce128 (bigprod, product.denom);
if (bigdeno.isbig)
{
return gnc_numeric_error (GNC_ERROR_OVERFLOW);
}
product = reduce128 (bignume, product.denom);
if (gnc_numeric_check (product))
{
return gnc_numeric_error (GNC_ERROR_OVERFLOW);
@ -473,13 +478,15 @@ gnc_numeric_mul(gnc_numeric a, gnc_numeric b,
}
else
{
while (bigprod.isbig)
while (bignume.isbig || bigdeno.isbig)
{
bigprod = shift128 (bigprod);
product.denom >>= 1;
bignume = shift128 (bignume);
bigdeno = shift128 (bigdeno);
}
product.num = bigprod.lo;
if (bigprod.isneg) product.num = -product.num;
product.num = bignume.lo;
if (bignume.isneg) product.num = -product.num;
product.denom = bigdeno.lo;
if (0 == product.denom)
{
return gnc_numeric_error (GNC_ERROR_OVERFLOW);