QString::fromLatin1(const QByteArray&) incorrectly handles zero-filled QByteArray

In previous Qt version passing of non-empty QByteArray filled with zeroes into QString::fromLatin1 results into empty QString.
For example this code worked correctly in previous Qt release and doesn't work in Qt 5.6 beta:

// modifies data filling it's contents
void GetAnsiString(char* data, size_t sz);

QByteArray buf(1024, Qt::Uninitialized);
GetAnsiString(buf.data(), buf.size());
QString str = QString::fromLatin1(buf);
if ( ! str.isEmpty() )
{
//...
}

The source of the problem is this commit which changed the behaviour of fromLatin1(QByteArray): https://codereview.qt-project.org/#/c/11530/1

Currently the calls QString::fromLatin1(buf) and QString::fromLatin1(buf.data()) will lead to different results in case of buf contains zeroes.

At least this should be documented.
But, IMHO, it's not a good approach to break existing functionality and even make it inconsistent. If someone would like to have a method which handles zeroes inside a buffer then a new method with suitable name should be created.

Link to the issue with a decision to not handle buffers with zeroes inside: https://bugreports.qt.io/browse/QTBUG-38553