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tweak yet another possible overflow path

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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
1 changed files with 17 additions and 10 deletions
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27
src/engine/gnc-numeric.c
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@ -421,7 +421,7 @@ gnc_numeric_mul(gnc_numeric a, gnc_numeric b,
gint64 denom, gint how) gint64 denom, gint how)
{ {
gnc_numeric product, result; gnc_numeric product, result;
qofint128 bigprod; qofint128 bignume, bigdeno;
if(gnc_numeric_check(a) || gnc_numeric_check(b)) { if(gnc_numeric_check(a) || gnc_numeric_check(b)) {
return gnc_numeric_error(GNC_ERROR_ARG); return gnc_numeric_error(GNC_ERROR_ARG);
@ -453,19 +453,24 @@ gnc_numeric_mul(gnc_numeric a, gnc_numeric b,
b.denom = 1; 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.num = a.num*b.num;
product.denom = a.denom*b.denom; product.denom = a.denom*b.denom;
/* If it looks to be overflowing, try to reduce the fraction ... */ /* 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 /* If rounding allowed, then shift until there's no
* more overflow. The conversion at the end will fix * 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) 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)) if (gnc_numeric_check (product))
{ {
return gnc_numeric_error (GNC_ERROR_OVERFLOW); return gnc_numeric_error (GNC_ERROR_OVERFLOW);
@ -473,13 +478,15 @@ gnc_numeric_mul(gnc_numeric a, gnc_numeric b,
} }
else else
{ {
while (bigprod.isbig) while (bignume.isbig || bigdeno.isbig)
{ {
bigprod = shift128 (bigprod); bignume = shift128 (bignume);
product.denom >>= 1; bigdeno = shift128 (bigdeno);
} }
product.num = bigprod.lo; product.num = bignume.lo;
if (bigprod.isneg) product.num = -product.num; if (bignume.isneg) product.num = -product.num;
product.denom = bigdeno.lo;
if (0 == product.denom) if (0 == product.denom)
{ {
return gnc_numeric_error (GNC_ERROR_OVERFLOW); return gnc_numeric_error (GNC_ERROR_OVERFLOW);