fix corner case in PolynomialGcd()

Task #144 - PolynomialGcd() fails for 0
grzegorzmazur · Nov 11, 2015 · be6284e · be6284e
1 parent 3ada818
commit be6284e
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Showing 2 changed files with 6 additions and 1 deletion.
diff --git a/scripts/stubs.rep/code.ys b/scripts/stubs.rep/code.ys
@@ -260,7 +260,10 @@ Sqrt(xlist_IsList) <-- MapSingle("Sqrt",xlist);
   PolynomialGcd(n, m, VarList(n*m)[1]);
 ];
 
-30 # PolynomialGcd(n_CanBeUni, m_CanBeUni, x_IsVariable) <--
+40 # PolynomialGcd(0, m_CanBeUni, x_IsVariable) <-- m;
+40 # PolynomialGcd(n_CanBeUni, 0, x_IsVariable) <-- n;
+
+50 # PolynomialGcd(n_CanBeUni, m_CanBeUni, x_IsVariable) <--
 [
   Local(vars);
   vars:=VarList(n*m);

diff --git a/tests/poly.yts b/tests/poly.yts
@@ -28,6 +28,8 @@ Verify(Gcd(2*x+2,4*x+4), 2*x+2);
 Verify(Gcd(x^2+7*x+6,x^2-5*x-6), x+1);
 Verify(Gcd(x^8+x^6-3*x^4-3*x^3+8*x^2+2*x-5,3*x^6+5*x^4-4*x^2-9*x+21), 1);
 
+Verify(PolynomialGcd(0, x, x), x);
+Verify(PolynomialGcd(x, 0, x), x);
 Verify(PolynomialGcd(2, 1/4, x), 1/4);
 Verify(PolynomialGcd(2*x+2, 4*x+4, x), 2*x+2);
 Verify(PolynomialGcd(x^2+7*x+6, x^2-5*x-6, x), x+1);