Feedly Breaks MathML

September 25th, 2023
tech
A few days ago I wrote about my experience with MathML, and despite being somewhat positive on it in that post I've decided to stop using it for now. The problem is, it doesn't display for people who follow my blog through RSS on (I'm guessing) most popular RSS system.

Here's a screenshot from my most recent MathML-containing post, on my website:

And here's the same portion of that post running in the web version of Feedly on the same browser:

Poking at developer tools, here's what Feedly is sending over the network to my browser:

<p> It definitely does look nicer: </p> <p> </p> <p> On the other hand

This shows that they're removing the MathML on the server, instead of there being some issue once it gets to the client.

This also explains why it doesn't work in other RSS readers that use Feedly as a backend. For example, I see the same thing in Palabre.

I tried to file a bug with them, but as far as I can tell you need to be a paid subscriber to do that. Authors trying to let Feedly know about bugs that impact their readers seems not to be a thing they're open to?

Here's a test case to reproduce this issue: mathml-simple.rss.

For now I'm going to stop using MathML, and go back to ascii math.

This makes me sad: during Nora's nap yesterday I wrote the MathML Verbosifier I'd been thinking of, which lets me write:

    a^2 + b^2 = c^2
as the relatively readable:
    <msup>a 2</msup> + <msup>b 2</msup> = <msup>c 2</msup>
and automatically convert that into the spec-compliant:
    <msup><mi>a</mi><mn>2</mn></msup><mo>+</mo><msup><mi>b</mi><mn>2</mn></msup><mo>=</mo><msup><mi>c</mi><mn>2</mn></msup>

(In the LW comments there was also discussion of whether I should avoid using MathML for the benefit of people running pre-v109 Chrome. I don't think that makes sense: there have been several serious vulnerabilities since then, including the WebP zero-day, and I'm not interested in making changes to my site to support people running dangerous configurations.)

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