Erroneous double-spacing when typing in markdown ell

[fonnesbeck]

Running notebook-4.2.3 installed via pip from master on Python 3.5.2 (Anaconda) on macOS 10.12.

Steps to reproduce:

1. Create new markdown cell in notebook
2. Begin typing prose

I notice that occasionally typing a single space will enter two spaces instead. Backspacing a single backspace will remove both spaces, but re-entering a space will add back two spaces. I can verify that they are two spaces by using the arrow key.

This occurs often, but irregularly.

[blink1073]

Hi @fonnesbeck, this may be related to jupyterlab/jupyterlab#522, are you using Safari < 10.0 by chance?

[fonnesbeck]

I am using Safari, but I am on 10.0.2.

Here is an animation of the behavior:

[blink1073]

Bummer, that is the same symptom we saw in JupyterLab, but switching to 10.0 on Safari fixed it for me.

[blink1073]

Do you mean that you installed from a source checkout? If so, what is the output of git describe?

[fonnesbeck]

I've installed from git master via pip this afternoon:

 pip install -U git+https://github.com/jupyter/notebook.git

[blink1073]

What does jupyter notebook --version say?

[fonnesbeck]

4.2.3

[blink1073]

When I run the same commands from a fresh conda env I get 5.0.0.dev. It looks like something else is shadowing version you tried to install this afternoon.

[blink1073]

In either case, I can't reproduce the issue from either 5.0.0.dev or 4.2.3 from PyPI, both in fresh environments using Safari 10.0.1. Hopefully someone else has further ideas.

[fonnesbeck]

I'm on 5.0.0.dev now, and the behavior persists. Editing markdown cells is not viable on Safari.

[gnestor]

Moving the conversation to #1967