Failed derivative mutates the mathematical expression

[sylee957]

Describe the bug

If I try-catch the evaluation of derivative, the expression gets unexpected mutation in-place if it fails
I'm using 12.0.0

To Reproduce
Steps to reproduce the behavior.

https://codesandbox.io/s/fast-worker-pnq7lf?file=/src/App.tsx

const expr = math.parse("min(x, y)");
console.log(math.format(expr));
try {
  const dx = math.derivative(expr, "x");
} catch {}
console.log(math.format(expr));

min(x, y) 
min(0, 0)

[josdejong]

Thanks for reporting!

Fixed via a1f3b7c (not yet published)

[josdejong]

The fix is published now in v12.1.0