Group paging does not work correctly when groups count is less than page size

[ag-petrov]

Bug report

When the number of groups is less than the page size count the grid does not display the entire set of groups, Reported in ticket - 1512639

Reproduction of the problem

Run this dojo - https://dojo.telerik.com/@efb@qad.com/eCizuraT

Current behavior

Only a subset of the groups is displayed

Expected/desired behavior

All the groups should be displayed

Environment

• Kendo UI version: 2022.3.915
• Browser: [all]

[StoyanGoranov]

Also reported in 1586580
Regression bug reproducible since 2020.3.915
https://dojo.telerik.com/@Stoyan/ejAfAHAk

[StoyanGoranov]

Reported in 1623001 as well.

[niwred]

In my tests, the problem showed up only when the PageSize was greater than number of groups but less than double the number of groups. The number of groups shown is PageSize - number of groups that should show. Example: Grouping results in 35 groups and Page Size is 50, 15 instead of 35 groups are shown. If the PageSize is 80 (> 70) the problem does not show up, all 35 groups are shown.

The same in the linked dojo. PageSize is 100, 77 groups should show, but 23 are shown. If you change the PageSize to 200, all 77 groups are shown.