Grid losing returned records with Virtual Scrolling enabled

[Rik]

We are running into issues with virtual scrolling in the kendo grid at certain numbers of total results.  We have our paging set to 10 per page and I have verified that our controller on the server is serving the correct records to the grid every time.  However, at certain levels of results there are exceptions being thrown from kendo.all.js.  These errors are "RangeError:  Maximum call stack size exceeded".  I have tested in IE7-9, FF, Chrome, and Safari and the errors are thrown in each of them (though they all point to different line numbers).  In fact, we can reliably produce a complete browser crash in FF and Safari by attempting to scroll up/down when the magic number of results is shown.

Here are the result totals returned and an explanation of what we observe (keep in mind, we have page size of 10 and we have pageable set to false):

 

• less than 10 results = shows results as expected
• 11 results – shows console error once on first click of down scroll, but the 11th record is never shown.
• 12 results – shows console error on first two clicks of down scroll, but never shows the 11th or 12th records.
• 13 results - shows two console errors for each of first two clicks of down scroll, but never shows the 11th / 12th  / 13th records.
• 14 results – shows console errors on first two clicks of down scroll and does not move the scrollbar.  However, on the third and subsequent clicks, the grid starts showing the fetched records.
• 15 results - shows console errors on first two clicks of down scroll and does not move the scrollbar.  On the third and subsequent clicks, the grid starts showing the fetched records.
• 17 results - shows console error on first click only of down scroll and does not move the scrollbar.  On the second and subsequent clicks, the grid starts showing the fetched records.
• 18 and over results – works correctly with no errors

Anyone else seeing this behavior?  This is really becoming a show stopper for us. 

[Rosen]

Hello Rik,

Unfortunately, I'm unable to recreate such behavior locally. Could you please check this sample (here is a short video which captures the local behavior) maybe I'm missing something obvious.  

Also note that virtual scrolling is design to be used with greater page size - 50+ records per page.

All the best,
Rosen
the Telerik team

[Rik]

Hi Rosen,

Not sure how your video or jsFiddle is supposed to test the issue I raised originally.  Your example always has a DataSource containing hundreds or more rows of data.  I don't have any issues with large amounts of data.  The issue is when I return between 11-16 rows of data in the DataSource. Can you test that scenario or adjust your jsFiddle to only have the various number of rows that I outlined in my original post. 

Thanks,
Rik

[Rosen]

Hi Rik,

Here is a test page which simulates total of 11 records return from the server. Unfortunately, I'm still unable to observe the error you have mentioned.

All the best,
Rosen
the Telerik team

[Rik]

Thanks Rosen. 

I am going to try and put together a small project that illustrates the issue.  I'll get that to you in the next day or so.