cancel error while save without change

lib/yukari.js

@@ -409,10 +409,22 @@ Yukari.prototype.update = function(callback) {
         }
     }
 
+    // FIX: if no data changed, then change all data
     if(!囍.size(data)) {
-        callback(new Error("No data changed."));
-        promise._onExecuteResult(new Error("No data changed."));
-        return promise;
+        for(var key in this) {
+            if(!this.hasOwnProperty(key)) continue;
+            if(key[0] === "$") continue;
+            if(typeof this[key] === "function") continue;
+
+            var fieldIdx = this._fieldAt(key);
+            if(-1 === fieldIdx) continue;
+
+            var field = this.$fields[fieldIdx];
+            data[field.name] = {
+                data: this[key],
+                field: field
+            };
+        }
     }
 
     // set data