Change-Id: Icb6da7c1d662261ec1b80fbd54d1b9dc7b573824

The decision to store the original QModelIndex as a role has the
unfortunate consequence that we need to emit the dataChanged() signal
whenever its value change. The previous implementation of the "move
rows" operation failed in delivering this update in most cases.

While addressing that, this commit also fixes some similar issues with
the HasChildren role not being notified in certain scenarios.

Also, when the last child of an expanded item gets moved away and later
placed back in the original position, the item should not remember its
expanded state, but rather accept the children while staying collapsed.

Last but not least, it's important that the endMoveRows() protected
method is called *after* the original tree model has completed its
movement, because otherwise its elements might be accessed while in the
wrong state.
Similarly, we don't want the dataChanged() signals to be emitted while
rows are moved or removed; we queue up these events and fire them only
after the item indexes have settled.

Fixes: QTBUG-59606
Change-Id: Ib981c912ea19908e1283cc463331c3053d4d6e7d
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

+ b37db1f31b3248e9d32d0ccbb42e77035fa5b340 Add changes file for Qt 5.12.5
+ da94d6586cbe6b9c12dec8ecc0f842aad807b0d3 Only calculate the height of the ListView when there are model entries
+ 7f61a351148c7d67f8f4ee6f2d2c4a9c53766297 Remove test_resizeAfterFlicking from tst_tumbler

Change-Id: I7bd32e2f04223df753615b0b3315244cef46e316
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

Change-Id: I6de0ffd4952bcecbcf92ff925d450ba4c4beb45f

This is causing flakiness in CI, and tests a weird edge case, so
its value as a test is very low.

Change-Id: Iaeb2633bd270dc8e88420ace5efe9ab156339733
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

When it tries to calculate the height of the listview then it depends
on the model having entries. If there is no model or no entries in it
then it will cause a warning to be outputted indicating that the
model size is less than 0. This prevents it from occurring as a result.

Fixes: QTBUG-72543
Change-Id: I7155a3a240fdcdf93caddfce332f0cc6bb0f0ec0
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

Change-Id: I9632a4f67cd4f96b0b5ad8010266463525f1f6e7

Change-Id: Ia5eba4c810e06c4b73daf6e27a8c5ce141ce6ebb