It's illegal to call elapsed() or restart() (sic) on a non-started QElapsedTimer, so don't do that. In QNAM code, this has been observed by adding assertions into QElapsedTimer, which then make network tests crash. (While I am unable to run the network testsuite, this is reproducible locally by running tst_QNetworkDiskCache::setCookieHeader). The QTextStream test also calls restart() without a start(), but then it calls elapsed()+start() which is the whole point of restart(), so amend accordingly. Pick-to: 6.9 6.8 6.5 Change-Id: I5cfe308f64b631b68b92843b409777a6b9176828 Reviewed-by: Marc Mutz <marc.mutz@qt.io> Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>