handle invalid precision

data.py

@@ -6,7 +6,7 @@ def have_location(x):
     return x.lat != None and x.lon != None
 
 def maybe_entry(x):
-    return x.eig < 5 and x.prec > 40
+    return x.eig < 5 and (x.prec > 40 or x.prec < 0)
 
 def maybe_indoor(x):
-    return x.eig < 1 and x.prec > 400
+    return x.eig < 1 and (x.prec > 400 or x.prec < 0)