array optional position argument [b] appears to not work

[tylercecil]

Issue Summary

My apologies in advance if I am mistaken / making no sense / filing in the wrong place.

This JS Bin shows a minimal example. You can see that top aligned seems to work, however bottom align works the same as top (center align works fine).

By chance, I noticed 2.7.5 seems to have the correct behavior. I am totally ignorant of the Mathjax project and its history, though, so... all it tells me is that there was a time when it worked.

I found #2083, which may be related?

Technical details:

• MathJax Version: 3.0.1
• Client OS: Arch Linux
• Browser: Chromium 80.0.3987.149 Arch Linux

[dpvc]

It turns out that there is an "off by one" error when determining the line to align at when working from the bottom of the array (so if you use more rows, you would see the alignment on the second to last row rather than the last one).

I have made a pull request to resolve the issue. Thanks for reporting it!

[tylercecil]

Thanks so much for the quick reply and fix! Glad it was simple enough.