Ctrl+0 only enlarges text in Help mode

1. Go to Help mode.
2. Use Ctrl+Scroll Wheel to make the text as small as possible.
3. Press Ctrl+0 (zero).
   The text grows bigger but stays rather small.
4. Use Ctrl+Scroll Wheel to make the text as large as possible.
5. Press Ctrl+0.
   The text resizes a bit.
6. Use Ctrl+Scroll Wheel to make the text as large as possible.
   It grows even bigger than before.

Ctrl+0 should resize the text to the default size.