After selecting a measure, with shift held down, clicking in another measure can lose selection
If I click in the right place in one measure to select that whole measure, then hold down shift and click in another measure, you can quite often lose the first selected measure, because it will try to select a notehead or notestem instead. If you've already selected one measure and keep SHIFT down, it should assume you only want to select measures and let you click anywhere in subsequent measures to select them.
GIT commit: f51dc11
Comments
To be clear, there issue is only if you shift+click something *other* than the note or rest. Click a note or rest will simply extend the selection to that note or rest, just as it should - it wouldn't be wrong to limit this functionality to full measures only. But indeed, it would be good if shift+click on something other than a note or rest did not lose an existing range selection.