Created attachment 364090 [details]
comparison screenshot

Environment:
- Fedora 27
- Terminal version:
  > $ rpm -q gnome-terminal
  > gnome-terminal-3.26.2-1.fc27.x86_64

Steps to produce:
1. open a GNOME Terminal window(my default size is set as 80*48)
2. maximize the terminal window and unmaximize it
3. check the window size

Expected result:
The window size after maximize and unmaximize should be the same.

Actual result:
The window size decreses. It might be difficult to find out the difference if
you only maximize and unmaximize once. Repeat step 2 multiple times, and you'll
see the difference clearly.