bug#31286: 26.1; edebug prevents closing

[Andreas Röhler]

Hi, this is a very old issue, don't see it at https://debbugs.gnu.org/:

when closing a file where a function was instrumented running edebug, 
Emacs refuses to get shut down afterwards. After answering the common 
closing questionaire, a buffer appears again and again showing

Debugger entered: nil
  edebug--display-1(nil 0 before)
  edebug--display(nil 0 before)
  edebug-debugger(0 before nil)
  edebug-before(0)
  ...

and thats it.

In GNU Emacs 26.1 (build 1, i686-pc-linux-gnu, GTK+ Version 3.14.5)
 of 2018-04-10