If the user has some objects selected and holds down the "extend selection"
key (Control on Windows, Command on Mac OS X), clicking and dragging a
rubber band selection deselects the current selection. This is
counter-intuitive and confusing for users.
This commit fixes the behavior so users can extend selections using the
rubber band when the proper key is held down.
Task-number: QTBUG-6523
Change-Id: Ieda4aaa50adb351c0405f5cb8aae23332eec58a9
Reviewed-by: Andreas Aardal Hanssen <andreas@hanssen.name>
75f2a0b4ef