74c59f8a23
ICU returns a "valid" representation of GMT when given an unrecognised ID, so QTZ's constructor has been checking the ID is available before passing it to the backend constructor. That availability check was done by generating the list of available IDs to see if the given ID was in it; this is very inefficient. Furthermore, the QTZ constructor was also checking availability, to work round the same issue in only this one backend, making the check redundant. So overide isTimeZoneIdAvailable() in the ICU backend, calling ucal_getCanonicalTimeZoneID(), which answers the question directly; and drop the duplicate check in the QTZ constructor. Expand a test to verify an invalid name is rejected. Fixes: QTBUG-121807 Pick-to: 6.6 6.5 Change-Id: I34f996b607b958d12607a94eb273bb1b406cca1a Reviewed-by: Thiago Macieira <thiago.macieira@intel.com> (cherry picked from commit 00d9a9a9b59650b8e297f91dcc600c377da5bceb) Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>