Zoom breaks decrease-width character-limit in org-mode (Spacemacs macOS 10.11)

[Jonta]

Reproduce:

• Open org-file in org-mode
• M-x writeroom-mode
• M-x writeroom-decrease-width until it's at 66 characters per line
• Zoom in with C-x +
• Fill a line with characters. 70 this time
• Esc :w to save (in EVIL-mode)
• Text jumps to the left a bit.

Spacemacs on macOS 10.11 - GNU Emacs 25.3.1 - (x86_64-apple-darwin15.6.0, NS appkit-1404.47 Version 10.11.6 (Build 15G20015)) of 2018-05-16 - Org mode version 9.1.13 (9.1.13-elpaplus @ /Users/jonta/.emacs.d/elpa/org-plus-contrib-20180514)

Related: Size of the font and other things #1. Over 6 years old, and supporting zoom seems like something that should work outside the box

Also: Conflict with Org Mode #30. I'm not using linum-mode.

[joostkremers]

What I suspect is going on is that the margins aren't adjusted after the text size change. When you save the file, this readjustment is done, so you see the text jump a bit.

This is (unfortunately) the way it's supposed to be: when the text size is changed, writeroom-mode should really readjust the margins, but there is no reliable way to do this. Text size changes cannot be detected, so writeroom-mode has no way of knowing when this happens. There is a workaround described in the README, which might or might not work.

But this is really just a guess. The problem may also be something else entirely. However, I cannot reproduce it, neither with my own config file, nor with emacs -Q. I don't use Spacemacs and I have no idea what customisations Spacemacs includes for Org and for writeroom-mode, so I can really only guess at what might be going on.