add additional case check and documentation comments for pruning logic

llarp/router/router.cpp

@@ -725,11 +725,14 @@ namespace llarp
     {
       GossipRCIfNeeded(_rc);
     }
-
+    const bool gotWhitelist = _rcLookupHandler.HaveReceivedWhitelist();
     // remove RCs for nodes that are no longer allowed by network policy
     nodedb()->RemoveIf([&](const RouterContact &rc) -> bool {
+      // don't pruge bootstrap nodes from nodedb
       if(IsBootstrapNode(rc.pubkey))
         return false;
+      // if for some reason we stored an RC that isn't a valid router
+      // purge this entry
       if(not rc.IsPublicRouter())
         return true;
       // clients have a notion of a whilelist
@@ -737,6 +740,14 @@ namespace llarp
       // routers that are not whitelisted for first hops
       if(not isSvcNode)
         return false;
+      // if we have a whitelist enabled and we don't
+      // have the whitelist yet don't remove the entry
+      if(whitelistRouters and not gotWhitelist)
+        return false;
+      // if we have no whitelist enabled or we have
+      // the whitelist enabled and we got the whitelist
+      // check against the whitelist and remove if it's not
+      // in the whitelist OR if there is no whitelist don't remoev
       return not _rcLookupHandler.RemoteIsAllowed(rc.pubkey);
     });