- fixed normal((b*a-c*a)/(4-a)) bug: heur_gcd() only works when both input

  polynomials are non-zero

diff --git a/ginac/normal.cpp b/ginac/normal.cpp
index b396771ff21a6367c09a34edd73a91f7f8e29537..514423c97930f4eff87ad74205553735069f3b26 100644 (file)
--- a/ginac/normal.cpp
+++ b/ginac/normal.cpp
@@ -1331,16 +1331,17 @@ static ex heur_gcd(const ex &a, const ex &b, ex *ca, ex *cb, sym_desc_vec::const
        heur_gcd_called++;
 #endif
 
        heur_gcd_called++;
 #endif
 

+       // Algorithms only works for non-vanishing input polynomials
+       if (a.is_zero() || b.is_zero())
+               return *new ex(fail());
+

        // GCD of two numeric values -> CLN
     if (is_ex_exactly_of_type(a, numeric) && is_ex_exactly_of_type(b, numeric)) {
         numeric g = gcd(ex_to_numeric(a), ex_to_numeric(b));
        // GCD of two numeric values -> CLN
     if (is_ex_exactly_of_type(a, numeric) && is_ex_exactly_of_type(b, numeric)) {
         numeric g = gcd(ex_to_numeric(a), ex_to_numeric(b));

-        numeric rg;
-        if (ca || cb)
-            rg = g.inverse();

         if (ca)
         if (ca)

-            *ca = ex_to_numeric(a).mul(rg);
+            *ca = ex_to_numeric(a) / g;

         if (cb)
         if (cb)

-            *cb = ex_to_numeric(b).mul(rg);
+            *cb = ex_to_numeric(b) / g;

         return g;
     }
 
         return g;
     }
 


@@ -1445,10 +1446,19 @@ ex gcd(const ex &a, const ex &b, ex *ca, ex *cb, bool check_args)
        // GCD of numerics -> CLN
     if (is_ex_exactly_of_type(a, numeric) && is_ex_exactly_of_type(b, numeric)) {
         numeric g = gcd(ex_to_numeric(a), ex_to_numeric(b));
        // GCD of numerics -> CLN
     if (is_ex_exactly_of_type(a, numeric) && is_ex_exactly_of_type(b, numeric)) {
         numeric g = gcd(ex_to_numeric(a), ex_to_numeric(b));

-        if (ca)
-            *ca = ex_to_numeric(a) / g;
-        if (cb)
-            *cb = ex_to_numeric(b) / g;
+               if (ca || cb) {
+                       if (g.is_zero()) {
+                               if (ca)
+                                       *ca = _ex0();
+                               if (cb)
+                                       *cb = _ex0();
+                       } else {
+                       if (ca)
+                           *ca = ex_to_numeric(a) / g;
+                       if (cb)
+                           *cb = ex_to_numeric(b) / g;
+                       }
+               }

         return g;
     }
 
         return g;
     }