fixes after static analysis by infer

.gitignore

@@ -20,3 +20,4 @@ README-orig.md
 TODO
 VERSION
 RELEASE-HOWTO.md
+infer-out

src/novas.c

@@ -4627,7 +4627,7 @@ int nutation(double jd_tdb, enum novas_nutation_direction direction, enum novas_
     return novas_error(-1, EINVAL, "nutation", "NULL input or output 3-vector: in=%p, out=%p", in, out);
 
   // Call 'e_tilt' to get the obliquity and nutation angles.
-  e_tilt(jd_tdb, accuracy, &oblm, &oblt, NULL, &psi, NULL);
+  prop_error("nutation", e_tilt(jd_tdb, accuracy, &oblm, &oblt, NULL, &psi, NULL), 0);
 
   oblm *= DEGREE;
   oblt *= DEGREE;

src/refract.c

@@ -163,7 +163,7 @@ double novas_radio_refraction(double jd_tt, const on_surface *loc, enum novas_re
   static const double E[] = { 0.0, 46.625, 45.375, 4.1572, 1.4468, 0.25391, 2.2716, -1.3465, -4.3877, 3.1484, 4.520, -1.8982, 0.8900 };
 
   double E0, TK;
-  double y = 1.0, z;
+  double y, z;
   double poly;
   double fptem;
   double refraction;