working but bad solution of "transaction close on onsuccess callback ended" problem.

src/jio.storage/indexeddbstorage.js

@@ -303,8 +303,7 @@
   };
 
   IndexedDBStorage.prototype.getAttachment = function (id, name, options) {
-    var transaction,
-      type,
+    var type,
       start,
       end;
     if (options === undefined) {
@@ -312,19 +311,32 @@
     }
     return openIndexedDB(this)
       .push(function (db) {
-        transaction = openTransaction(db, ["attachment", "blob"], "readonly");
+        return new RSVP.Promise(function (resolve, reject) {
+          var transaction = openTransaction(db, ["attachment", "blob"],
+            "readonly"),
             // XXX Should raise if key is not good
-        return handleGet(transaction.objectStore("attachment")
-                         .get(buildKeyPath([id, name])));
-      })
-      .push(function (attachment) {
-        var total_length = attachment.info.length,
+            request = transaction.objectStore("attachment")
+            .get(buildKeyPath([id, name]));
+          request.onerror = function (error) {
+            transaction.abort();
+            reject(error);
+          };
+          request.onsuccess = function () {
+            var attachment = request.result,
+              total_length,
               i,
               promise_list = [],
               store = transaction.objectStore("blob"),
               start_index,
               end_index;
 
+            if (!attachment) {
+              return reject(
+                new jIO.util.jIOError("Cannot find attachment", 404)
+              );
+            }
+
+            total_length = attachment.info.length;
             type = attachment.info.content_type;
             start = options.start || 0;
             end = options.end || total_length;
@@ -353,7 +365,9 @@
                   name, i])))
               );
             }
-        return RSVP.all(promise_list);
+            resolve(RSVP.all(promise_list));
+          };
+        });
       })
       .push(function (result_list) {
         var array_buffer_list = [],
@@ -413,10 +427,12 @@
         }
 
         // Remove previous attachment
-        transaction = openTransaction(db, ["attachment", "blob"], "readwrite");
+        transaction = openTransaction(db, ["attachment", "blob"],
+          "readwrite", false);
         return removeAttachment(transaction, id, name);
       })
       .push(function () {
+        transaction = openTransaction(db, ["attachment", "blob"], "readwrite");
 
         var promise_list = [
             handleRequest(transaction.objectStore("attachment").put({