getSelectedRows cannot return selected groupHeader rows

[troywoy]

Obtaining the selected rows when enableGroupHeaderSelection: true is applied will never return group rows, as seen in this plunkr. If you select row(s) and then click the console.log(...) button, it will only ever log child rows regardless of what groups you have selected.

The getSelectedRows service method acts upon grid.rows which is the flat data array, there is no treeBase traversal.

This can be associated with Issue #6126, as both relate to getSelectedRows acting upon grid.rows and nothing associated with treeBase.

[RepoCorp]

I'm experiencing the same problem described here and I can see it is solved in #6556. But then the changes introduced in that PR were reverted in b21096b.

I just need to have any information on the selected header row, or even in any of the children rows, when the user clicks in a group header row.