[X] $regexp non-greedy fails

[chrisjj]

$regexp(axxxz,x.*?z,) give a rather than axx as documented:

https://docs.mp3tag.de/actions/replace-regexp
Non-greedy repeats
Non-greedy repeats are possible by appending a '?' after the repeat; a non-greedy repeat is one which will match the shortest possible string.

[Florian]

You have to keep in mind that regular expressions are evaluated from left to right.

Considering your example, the engine starts at a

1. a does not match against the pattern
2. x does match partially and gets consumed
3. x does match partially and gets consumed
4. x matches because it is followed by a z and both get consumed.

Not a bug in the regexp engine.