QPushButton breaks QFormLayout on Mac

[yura-vel]

I use QLineEdit and QPushbutton in the form layout, like scribed "here":http://blog.qt.digia.com/blog/2008/07/07/usage-of-the-qformlayout/
In result the spacing between rows in the form are broken.

The similar problem discussed "here":http://stackoverflow.com/questions/18612370/qpushbutton-creates-empty-space-on-mac-os-x-resulting-in-ugly-layouts (look at the snapshots).

But efficient solution not have been proposed.
How to remove extra spacing?

setContentsMargins applied to button or layout has no effect