Re: Strange bug with or without quotes

>
> When you use quotes around an array parameter, joining happens first, so
> before the :# operation (or any other expansion operation). The (@) forces
> the :# operation to work on the array elements *and only then join the
> result*.
>

Actually that last part is wrong. The (@) cancels the joining.
"${(M@)array:#pattern}"
returns multiple strings if "array" contains multiple elements that match
"pattern". If instead you need a single string, you can force the joining
with either "${(j: :M@)array:#pattern}" or "${${(M@)array:#pattern}}".

Philippe