The Style, Font and Size combo boxes in writer, when modified with the mouse wheel, the values are changed accordingly, but is has no effect what so ever on the current document.
Steps to Reproduce:
1.Type in some text and select it.
2.Hover the mouse pointer to the font size combo box, for example.
3.Change the size with the mouse scroll wheel.
Current selection reflects the selected font size value --or-- New entered texts uses the selected value --or-- disable the ability to change the combo boxes whits the scroll-wheel.
User Profile Reset: No
User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:58.0) Gecko/20100101 Firefox/58.0
*** This bug has been marked as a duplicate of bug 37048 ***