[REVIEW-3-6] fix for fdo#52351, remove conditional formatting if all its cells are removed

[Stephan Bergmann]

On 08/06/2012 04:08 PM, Kohei Yoshida wrote:
> Regarding
>
>          iterator itr = begin();
>          while(itr != end())
>          {
>              if(itr->GetRange().empty())
>                  maConditionalFormats.erase(itr++);
>              else
>                  ++itr;
>          }
>
> that erase line causes an undefined behavior, and subtle, hard-to-find
> bug later.  maConditionalFormats is a boost::ptr_set which uses
> std::set in its implementation.  The std::set's erase call invalidates
> the iterator of the element that has just been deleted, and that line
> increments the iterator after it's been invalidated.

No, the line first increments itr, then calls erase (on the old itr value).

Stephan