portpolicy: note a spec issue

TODO

@@ -69,7 +69,8 @@ MILESTONE 3: Clean and tidy
        - complete coverage on tor-proto arti#13 (2)
    - Refactor XXXX and TODO code; make sure everything is tested and
      documented.  (1-4??)
-        - [arti#15 to make a list of these]
+        o [arti#15 to make a list of these] (1h)
+        - [arti#24 to resolve them]
    - expand documentation in tor-proto, tor-netdir, tor-netdoc,
      tor-cell. arti#16 (0.5)
    - Is this "reactor" business a sensible design?  Is there a better one?

tor-netdoc/src/types/policy/portpolicy.rs

@@ -75,8 +75,9 @@ impl PortPolicy {
     /// gives an error if this range cannot appear next in sequence.
     fn push_policy(&mut self, item: PortRange) -> Result<(), PolicyError> {
         if let Some(prev) = self.allowed.last() {
+            // TODO SPEC: We don't enforce this in Tor, but we probably
+            // should.
             if prev.hi >= item.lo {
-                // Or should this be ">"? TODO XXXXM3
                 return Err(PolicyError::InvalidPolicy);
             } else if prev.hi == item.lo - 1 {
                 // We compress a-b,(b+1)-c into a-c.