When there are less than 3 assets opening the thumbnail view in the assets app results in a division by zero error.

In info.magnolia.ui.workbench.thumbnail.JcrThumbnailContainer#setPageSize pageSize gets divided by 3, but since this in an integer division 2/3 = 0.

Then in AbstractJcrContainer#updateOffsetAndCache you get a division by zero in this code:

currentOffset = (index / (pageLength * cacheRatio)) * (pageLength * cacheRatio);

(Maybe this calculation should be more like the one in AbstractJcrContainer#indexOfId, which has a similar statement, but with +1 in the division?)