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>
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