QHeaderView::reset() should reset logical indices

Platform
Linux
Platform details
Compilers
GCC

Steps to reproduce / test case

1. initialize a QTableView with a custom but basic model (inheriting from QTableModel) with, say, 9 columns.
2. set the table view headers movable.
3. have a model reset that in fact is triggered by just one column added at the last position

• at this point everything's well, see below.
  4. in the view, move the new column somewhere in the middle, let's say at visual index 7
  5. remove the last (most recent) column from the model and let the model emit reset() instead of column removed signals.
  6. now, logicalIndex(7) on the header returns 9 but there are just 9 columns left...
  More information
  When QHeaderView::reset() is called the logical indices (QHeaderViewPrivate::logicalIndices) are not correctly reset nor their mapping with QHeaderViewPrivate::visualIndices. See both QHeaderView::initializeSections() functions, particularly lines 1939 ff of qheaderview.cpp. Indices inferior to new column count are left untouched). At step 3, above, the view was correctly updated b the new count is superior to the old count.

The only way I found to reset the indices and their mapping is through connections established in QHeaderView::setModel() since QHeaderView::sectionsInserted and QHeaderViewPrivate::_q_sectionsRemoved seem to behave in a nicer way, but this is somewhat inconvenient since this forces the model to emit signals to mimick erasing of all columns then insertion of all new columns.

At the very least, the default should be documented.