Hi,

I've noticed that the musl regex implementation behaves slightly differently than the glibc implementation. I'm attaching a short program showing the behaviour.

The difference makes yate (http://yate.null.ro) misbehave when running with musl (reported here: https://github.com/openwrt/telephony/issues/378).

Yate uses a regexp like this:

"^\\([[:alpha:]][[:alnum:]]\\+:\\)\\?/\\?/\\?\\([^[:space:][:cntrl:]@]\\+@\\)\\?\\([[:alnum:]._+-]\\+\\|[[][[:xdigit:].:]\\+[]]\\)\\(:[0-9]\\+\\)\\?"

.. to parse strings like:

"sip:012345678@11.111.11.111:5060;user=phone"

.. and the matches produced by musl are:

Match 0: 0 - 32        sip:012345678@11.111.11.111:5060
Match 1: -1 - -1
Match 2: 0 - 14        sip:012345678@
Match 3: 14 - 27        11.111.11.111
Match 4: 27 - 32        :5060

.. while glibc produces:
Match 0: 0 - 32        sip:012345678@11.111.11.111:5060
Match 1: 0 - 4        sip:
Match 2: 4 - 14        012345678@
Match 3: 14 - 27        11.111.11.111
Match 4: 27 - 32        :5060

What do you think?

I've only tested musl 1.1.19. Sorry if this is not valid for later releases. I skimmed the 1.1.20 release notes and didn't find anything regex related.

Regards

Robert