[lmi] Can't delete repeatedly from list end in CensusView [Was: switch census view to use wxDataViewCtrl]

[Greg Chicares]

On 2011-08-03 23:42Z, Greg Chicares wrote:
> On 2011-08-03 19:21Z, Greg Chicares wrote:
[...]
> This made it easier to stumble across a hitherto-unnoticed defect that
> I'll describe in a follow-up message.

To reproduce [some commands are deliberately duplicated]:
  File | New | Census
  Census | Add cell
  Census | Add cell
  Census | Delete cell(s) | Yes
  Census | Delete cell(s) | Yes
That causes:
  Assertion 'expurgated_cell_parms.size() == n_items - n_sel_items' failed.
  [file /lmi/src/lmi/census_view.cpp, line 931]

AFAICT, repeated deletions from the top or the middle succeed, and this
defect appears only for repeated deletions from the end.

If I always select the bottom row before deleting it, then everything seems
to work okay. Otherwise, after the first deletion, no row has the selection
highlight, but there's apparently an attempt to delete something, because
the confirmation dialog says:
  Confirm deletion
  Irrevocably delete 1 of 2 cells?
  Yes   No