From aca404f7e872d0fca51090e8855d5cbeebc99227 Mon Sep 17 00:00:00 2001
From: Steven Orvell <sorvell@google.com>
Date: Tue, 10 Nov 2015 15:15:04 -0800
Subject: [PATCH] For correctness, bind listeners must use a property's current
 value rather than its passed value.

---
 src/lib/bind/accessors.html | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/lib/bind/accessors.html b/src/lib/bind/accessors.html
index 679ffae269..66175deae6 100644
--- a/src/lib/bind/accessors.html
+++ b/src/lib/bind/accessors.html
@@ -219,7 +219,12 @@
         if (targetPath) {
           this._notifyPath(this._fixPath(path, property, targetPath), value);
         } else {
-          value = value !== undefined ? value : target[property];
+          // TODO(sorvell): even though we have a `value` argument, we *must*
+          // lookup the current value of the property. Multiple listeners and
+          // queued events during configuration can theoretically lead to 
+          // divergence of the passed value from the current value, but we 
+          // really need to track down a specific case where this happens.
+          value = target[property];
           if (!isStructured) {
             this[path] = value;
           } else {