An md file, or notebook cell, ending in a blockquote with a blank line, causes a crash

[fperez]

Describe the bug

Consider a notebook that contains the following cell:

> test
>

or a markdown file with the above. The key point is that the cell/markdown content must end with a blockquote that has a blank line at the end, still part of the block quote. The python short traceback is (I'll attach the long one):

Exception occurred:
  File "/Users/fperez/local/conda/lib/python3.9/site-packages/markdown_it/rules_block/blockquote.py", line 158, in blockquote
    if state.srcCharCode[pos] == 0x20:  # /* space */
IndexError: tuple index out of range

Reproduce the bug

Running a build with a notebook with the above (or an md file) should suffice.

List your environment

> jupyter-book --version
Jupyter Book      : 0.11.3
External ToC      : 0.2.3
MyST-Parser       : 0.13.7
MyST-NB           : 0.12.3
Sphinx Book Theme : 0.1.10
Jupyter-Cache     : 0.4.3
NbClient          : 0.5.10

[welcome]

Thanks for opening your first issue here! Engagement like this is essential for open source projects! 🤗

If you haven't done so already, check out EBP's Code of Conduct. Also, please try to follow the issue template as it helps other community members to contribute more effectively.

If your issue is a feature request, others may react to it, to raise its prominence (see Feature Voting).

Welcome to the EBP community! 🎉

[fperez]

Full Sphinx error log:

sphinx-err-06zb0e7h.log

[fperez]

@facusapienza21 - note this - Lab 1 for S159 was causing this crash and it took me a while to track down the issue. Since it's a bug in markdown-it upstream, for now we can work around it by adding an extra blank line in cells that have block quotes, but I wanted you to be aware so you don't burn time on it...

[hukkin]

Since it's a bug in markdown-it upstream

To clarify, I don't think this is an issue in upstream Javascript markdown-it, but rather a porting issue in markdown-it-py.

I've fixed this in #186

[chrisjsewell]

Heya, yeh thanks, it is indeed a porting issue that I thought we had fully fixed already 😳.
Basically, for array[outofbounds_index] JS returns null (thus no crash) but Python raises an IndexError

[fperez]

Thanks folks for the super-quick response! And yes @hukkin - I meant markdown-it-py, sorry for being imprecise in the js/py distinction :)

I greatly appreciate the quick fix, we'll roll it out into our working image once it's part of the next release.

[chrisjsewell]

cheers!
(FYI, in case you didn't notice, jupyter-book/jupyter-book#1181 was closed with jupyter-book v0.12)

[fperez]

Awesome - I hadn't noticed the 1181 fix, but that's much appreciated!

[chrisjsewell]

It's been hanging around at this "level" for a while, just had to float its way up to jupyter-book lol