Fix a race condition with key deletion.

lib/proxy/keys.js

@@ -26,8 +26,12 @@ function ProxyKeys(config) {
 ProxyKeys.prototype.load = function(cb) {
   var this_obj = this;
 
+  // Keep track of the keys that were registered as of now so that we can compare against
+  // the list we're about to load.  Anything that remains in delete_me should be, like, deleted.
+  var delete_me = {};
+
   _.each(this_obj, function(value, key) {
-    delete this_obj[key];
+    delete_me[key] = true;
   });
 
   var key_count = 0;
@@ -70,6 +74,8 @@ ProxyKeys.prototype.load = function(cb) {
           // of the current object.  These properties are enumerable and configurable, so future runs
           // of the load command will be able to delete and re-add these properties as necessary.
           Object.defineProperty(this_obj, file_name, { value: encoding.encodeData(file_contents), configurable: true, enumerable: true });
+          // We don't want to delete this property, so delete it from delete_me.
+          delete delete_me[file_name];
 
           // Increment the key count
           ++key_count;
@@ -86,6 +92,11 @@ ProxyKeys.prototype.load = function(cb) {
       }
     });
 
+    for (var key_to_delete in delete_me) {
+      logger.info("Deleting key %s", key_to_delete);
+      delete this_obj[key_to_delete];
+    }
+
     // Set the count property of this object.
     this_obj.count = key_count;