`[/]` in text field does not appear on canvas

[AdrianGroty]

When a forward slash between square brackets is part of the string in the text field, it does not appear on the canvas.

Steps to reproduce:

1. Create a text object with a
2. Type test [/] and confirm with enter

The text object reads as "test" in the canvas but as "test [/]" in the backing sheet. An object containing only [/] will not appear in the canvas at all but will still exist in the backing sheet.