Wrong toolbar layout in Qt 5.13 (regression)

Toolbar contents are not vertically centered with Qt 5.13 anymore. That may not be easily seen with Fusion but, in the attached screenshot, I've intentionally set "PM_ToolBarItemMargin" and "PM_ToolBarFrameWidth" to 10 for it to be clearly visible with the Kvantum widget style.

I've also attached a diff file that shows the differences between qtoolbarlayout.cpp in Qt 5.12 and Qt 5.13. The coefficient 2 is missing in several places of Qt 5.13 (search for "2*" in the diff file).

EDIT: The fix is also attached.