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

This reverts commit 357d923c.
nexedi/rsvp.js!1 fix it by more elegant way

src/jio.storage/indexeddbstorage.js

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