All our tests were find() == end() or !=, which depends on the evaluation order of the arguments to operator==(). If end() is called first, then the detach happens before find() and all is well. But if find() is called first, it may return end() before end() detaches. [ChangeLog][QCborMap] Fixed a bug that could cause the iterator returned from a failing key search with find() not to match end(). Now, every call to find() will detach in shared QCborMaps; to avoid this, use constFind() and constEnd(). Fixes: QTBUG-84583 Pick-to: 5.15 5.12 Change-Id: I552d244076a447ab92d7fffd161793496a8d03a8 Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>