If you have never listened to PJ Vogt’s Search Engine podcast, you are missing out. Vogt is one of the most inquisitive minds out there. He can turn any seemingly inane fact into an intricate story that often leads to unexpected places.

Recently, he came across a strange fact: iPhone audio messages mentioning the name of a specific restaurant chain wouldn’t get delivered. He set out to find out why, and he did it. Sort of.

Spoiler alert

Just as Gui Rambo says in the post we’ll get to shortly, here’s my fair warning: you really, really, really should listen to the Search Engine episode before reading on.

First, because I don’t want to rob you of the journey Vogt takes you on, while he discovers why an iPhone just won’t receive audio messages that mention a specific restaurant chain.

Second, because I’m convinced Search Engine will become one of your favorite shows. You’ll be hard-pressed not to mention something you learned from an episode in your next pub conversation. Trust me.

OK? OK.

So, as Vogt and cybersecurity expert Alex Stamos figure out, the problem is that when iOS transcribes the audio message, it interprets the ampersand in Dave & Buster’s as code instead of an actual ampersand text character.

As it turns out, in cases like this, Apple should do what is known in programming as “escaping,” which basically tells the system that it should interpret a specific character as text instead of code.

Good enough for most people, but not good enough for Gui Rambo. He wanted to know what (and how) exactly crashed in the system when the iPhone received the audio message containing the mention of Dave & Buster’s. So he did a bit of spelunking of his own.

In his recent blog post about it, you can see the error logs and exactly how iOS behaves when it expects code that never arrives. You can also see what happens when the audio message gets parsed and transcribed, and everything falls apart.

For what it’s worth, Apple already confirmed to Vogt that it plans to fix this bug in an upcoming iOS update, so if you want to test it for yourself, you’d better do it soon.