regression in charts introduced by one of the recent table to std::map commits

[Markus Mohrhard]

Hello Noel,

>
> I just noticed that one of the following commits introduced a serious
> regression in chart2. Can you please recheck them by opening the test
> document in fdo#47632 and switch to edit mode. Then select one data
> series and select the chart type menu entry in the pop-up menu. This
> will immediately crash in chart2uno with a null pointer dereference.
>
> 3ffdb45ae047f12480e73fdd4b28fe35f1e8d48c
> 4aa72e0dee42c80667083c0b86a3d0ec5381c1ae
> 13bf19769e6e0522d920594225b9baa2c1b7dd63
> 6af00cf90f4314be11ac7d8f186bb9da4f228cf1
> db3786ee3aa0d8911042c9bbcea02cf36d96dfa1
>

Sorry had to revert these commits for now. They are breaking the
Linux-RHEL6-x86_64 at 14-with-check tinderbox. If you don't have enough
time to look into them please drop me a note and I will try to look
into them next week.

Just a short hint from what I saw while debugging the tinderbox
failure. It seems that your changes now sometimes result in empty data
sequences which results in empty charts. Please note that for testing
that charts are generated correctly you need to switch to chart edit
mode, otherwise it might happen that you only see a cached picture.

Regards,
Markus