add degree test, modify divrem for 0 degree

Author: jverzani

src/Polynomials.jl

@@ -199,7 +199,7 @@ function divrem{T, S}(num::Poly{T}, den::Poly{S})
         error("Polynomials must have same variable")
     end
     m = degree(den)
-    if m < 0
+    if m == 0 && den[0] == 0
         throw(DivideError())
     end
     R = typeof(one(T)/one(S))

test/tests.jl

@@ -32,6 +32,8 @@ sprint(show, pNULL)
 @test pNULL^3 == pNULL
 @test pNULL*pNULL == pNULL
 
+@test map(Polynomials.degree, [pNULL,p0,p1,p2,p3,p4,p5,pN,pR,p1000]) == [0,0,0,1,2,3,4,4,2,999] 
+
 @test polyval(pN, -.125) == 276.9609375
 @test polyval(pNULL, 10) == 0
 @test polyval(p0, -10) == 0