Paired notebook cannot be opened in Jupyter following "jupytext --to ipynb"

[mwouts]

We already saw this at #254 - Jupytext in Jupyter checks that the .md file is more recent than the .ipynb file, to avoid overwriting an .ipynb file with the possible out-of-date content of the .md file.

However, when the .ipynb file is written by Jupytext itself (and is the dual of the source .md file), we know that the content there does match that of the .md file.

So maybe when one executes jupytext --to ipynb notebook.md, Jupytext should also update the timestamp of the input notebook.md? Before that, one should check the impact of changing the timestamp on editors like Jupyter notebook, VS Code or PyCharm - will they infer that the file content has changed?

[mwouts]

Updating the timestamp of a Python script does not seem to create issues with PyCharm nor VS code (at least on Windows). So there's a chance that implementing this won't cause more trouble than it solves!

The corresponding fix is available on branch 1.3.0.

[mwouts]

The timestamp update could be limited to the cases when

• output is .ipynb
• and the notebook is a paired notebook.