Changeset 19ee5eb in git for libpolys/coeffs/rmodulon.cc

Timestamp:

Feb 1, 2021, 1:32:52 PM (3 years ago)

Author:

Hans Schoenemann <hannes@…>

Branches:

(u'fieker-DuVal', '117eb8c30fc9e991c4decca4832b1d19036c4c65')(u'spielwiese', '38dfc5131670d387a89455159ed1e071997eec94')

Children:

4218c13e2434358d0a056b78d0a40377a11bcdb1

Parents:

f60ab1f6c47a09dc3472f9d3cabd270622c46327

Message:

fix: division by 0: return 0, not NULL

File:

• libpolys/coeffs/rmodulon.cc (modified) (3 diffs)

libpolys/coeffs/rmodulon.cc

@@ -248 +248 @@
   mpz_ptr erg = (mpz_ptr)omAllocBin(gmp_nrz_bin);
   mpz_init(erg);
-  mpz_invert(erg, (mpz_ptr)c, r->modNumber);
+  if (nrnIsZero(c,r))
+  {
+    WerrorS(nDivBy0);
+  }
+  else
+  {
+    mpz_invert(erg, (mpz_ptr)c, r->modNumber);
+  }
   return (number) erg;
 }
@@ -547 +554 @@
 static number nrnDiv(number a, number b, const coeffs r)
 {
-  if (r->is_field)
+  if (nrnIsZero(b,r))
+  {
+    WerrorS(nDivBy0);
+    return nrnInit(0,r);
+  }
+  else if (r->is_field)
   {
     number inv=nrnInvers(b,r);
@@ -613 +625 @@
   omFreeBin(g, gmp_nrz_bin);
   return (number)rr;
-}
-
-static number nrnIntDiv(number a, number b, const coeffs r)
-{
-  mpz_ptr erg = (mpz_ptr)omAllocBin(gmp_nrz_bin);
-  mpz_init(erg);
-  mpz_tdiv_q(erg, (mpz_ptr)a, (mpz_ptr)b);
-  return (number)erg;
 }