when building day's log, skip stubs

src/main.rs

@@ -96,8 +96,13 @@ fn log(f: &String, enabled: &bool, since: &Option<String>) -> Result<(), String>
          0 => 1.0,
          _ => ((tsheet.xs[i].t - tsheet.xs[i-1].t) as f32 / (60.0*60.0)) as f32,
       };
-      curr.t = x.timestamp();
-      curr.xs.push(LogX{d: d, x: x.x.clone()});
+      match x.x.len() {
+         0 => {},
+         _ => {
+            curr.t = x.timestamp();
+            curr.xs.push(LogX{d: d, x: x.x.clone()});
+         },
+      };
    }
    if curr.xs.len() > 0 {
       result.push(curr.clone());