corelib/tools/qelapsedtimer_mac.cpp, static qint64 absoluteToNSecs(qint64 cpuTime)

Integer overflow in line:

qint64 nsecs = cpuTime * info.numer / info.denom;

On PowerPC Macs, info.numer can be 1,000,000,000. Multiplying this by cpuTime can overflow the maximum value of qint64, leading to all sorts of wacky results. Suggested fix:

qint64 nsecs = cpuTime * ( (double)info.numer / (double)info.denom );

(As an aside, wherever absoluteToNSecs() or absoluteToMSecs() are called it is smashing an unsigned integer into a signed integer. But I haven't found that to be problematic.)

Worst case scenario: on a QThread that has a QTimer with a 5 second repeating timeout, this integer overflow may cause QTimerInfoList::timerWait to calculate a timeval that is too big for system ::select() to handle, which causes ::select to return EINVAL, which forces the event loop into a cpu-hogging cycle.