kcm_clock: Check for valid return values of QDateTime::toTime_t()
Review Request #113152 - Created Oct. 7, 2013 and discarded
Using the date selector in kcm_clock to set any date further than February 7, 2106 resulted in setting the time to ((time_t) (unsigned int) -1). This patch makes setting any date further than this to spit out an DateError. Also, it's a seed for discussion regarding this KCM module as passing the values as QStrings and converting from/to time_t doesn't seem like a manageable solution to the problem. Thanks for your opinions.
Built and tested on Fedora 19 x86_64.