Spreadsheet: incorrect block names for MBs with multi-pieces

Hello,

With some data, the field Block name in a selection is something like "unamed_3", instead of the real black name. This is the case with the data exemple shuttle_surf.vtm.

In the Find Data panel, I can see the real block name when I choose selection criteria (in the "block selection", but not in the selected data area.

For other data such as can.ex2 the block name is OK ("block 1" and "block 2" in the selected data area).

I work on paraview almost master (commit 65c3f5c8).

Thanks for helping =) Eloïse