Created by: cben
If I see a [Math Processing Error], its error message is something non-informative like
Error: Cannot read property 'firstChild' of null.
This (or something similar) would help a lot — if not me than you after I file a better bug report :-)
[will file separately for the actual errors that prompted this]
PLEASE TEST.
I only tried this on Chrome and Firefox (Linux) and didn't run any test suite.
The if(err.stack) test sounds safe to me (and https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/Stack claims wide support) but I'm the kind of web dev who breaks stuff in prod and doesn't notice for months...