Pressing backspace creating a slug then deletes again:

• Create a new page (or go to an existing one), and enter "AB\nCD\nEF"
• Place the cursor down-page of "F" and press backspace; "F" is deleted correctly.
• Then press backspace again; "E" is deleted, as is the remaining slug, and the cursor moves us.

Version: unspecified
Severity: critical