Test starting at 0.

src/test-gradient-method.cc

@@ -67,6 +67,12 @@ void testSampleFunction() {
 
   double const ret2 = functionTester(J, start, 10);
   assert(std::abs(ret1 - ret2) < 1e-5);
+
+  start[0] = 0;
+  start[1] = 0;
+
+  double const ret3 = functionTester(J, start, 3);
+  assert(std::abs(ret1 - ret3) < 1e-5);
 }
 
 void testSampleFunctionNonsmooth() {