[O] Bug: org-hierarchical-todo-statistics + org-update-statistics cookies in before-save-hook breaks overlays [8.3.5 (8.3.5-elpaplus @ /home/clement/.emacs.d/.cask/25.1.50.7/elpa/org-plus-contrib-20160719/)]

[Clément Pit--Claudel]

Hi emacs-orgmode,

Setting ‘org-hierarchical-todo-statistics’ to nil confuses 
‘org-update-statistics-cookies’ when that function is used in a 
before-save-hook.

More precisely, every time I save the attached org file, the hidden section of 
the buffer shrinks a bit, revealing a few characters at the end of the buffer. 
This is weird. Fortunately, it's reproducible in emacs -Q. Here's a video: 
http://asciinema.org/a/1h4otbt9cviod3nef0nx1sa5s

I have attached minimal org.el and test.org files. With these, run

  emacs -Q -l org.el test.org

Then make a change on the first line and save. This will reveal a few 
characters at the end of the file-local variables section. Repeating the 
edit+save cycle shows a few more characters each time (if this is abstruse, 
watch the asciinema video above)

Let me know if I can provide more information!

Cheers,
Clément.

Emacs  : GNU Emacs 25.1.50.7 (x86_64-pc-linux-gnu, GTK+ Version 3.18.9)
 of 2016-07-20

org.el
Description: Text Data

test.org
Description: Lotus Organizer

signature.asc
Description: OpenPGP digital signature