consistently handle empty program string in QProcess::start overloads

All overloads of QProcess::start will now check whether the program
string is empty and in that case
  - set error to FailedToStart,
  - set errorString to "No program defined",
  - emit error.

Until now only one of the three overloads behaved like this.

As a side effect, start(QString(), QStringList()) will not crash on
Windows anymore.

Task-number: QTBUG-47404
Change-Id: I2f93657204fe3643b1d74a74817843c05fc4a96b
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>

0 files changed, 0 insertions, 0 deletions