configure: fix non-portable "==" tests

[CyberTailor]

Bug: https://bugs.gentoo.org/879533

[sjaeckel]

Basically LGTM!

Would it maybe make sense to add a CI Job which uses dash as default shell, so we can detect stuff like this earlier?

[NexAdn]

Would it maybe make sense to add a CI Job which uses dash as default shell, so we can detect stuff like this earlier?

Maybe there is a linter which can check for bashisms in scripts that should be POSIX-compatible? If not, It should be pretty easy to add another matrix variable which just iterates over bash and dash as interpreter

[CyberTailor]

There's checkbashisms but it gives false positives.

So I went with dash -n.

[sjaeckel]

I like that approach 👍 and TBH I prefer it over some script

Just to be sure I added the revert of 7352bd5 to check whether the added test does its job... and apparently it doesn't do what it should :D

I didn't get dash -n ./configure to break ... don't ask me why

In the end I got it to break locally, but doing so required to uninstall bash ... why? I'm not sure... maybe something inside autotools prefers using bash if it can find it!?

The easiest way I found would be to run configure under dash, can you please fixup your commit be01be5 with a1ddc31 and force-push?

[sjaeckel]

CI Run https://github.com/strophe/libstrophe/actions/runs/3450924402/jobs/5759814792 shows that it works now as intended!

Thanks @CyberTailor for reporting this