Fix GH-15565: --disable-ipv6 during compilation produces error EAI_SYSTEM not found

[ndossche]

No description provided.

[cmb69]

Thank you! This looks good to me (I'm still trying to find where that macro is actually defined, though, out of interest).

[cmb69]

I'm still trying to find where that macro is actually defined, though, out of interest

Wrong question. It's about:

php-src/win32/build/config.w32

Line 332 in 6351468

AC_DEFINE('HAVE_GAI_STRERROR', 1);

Not sure that ca6dd7e was correct (well, seems it was according to what we had). But why did we define HAVE_GAI_STRERROR only for IPv6 support? And why do we use gai_strerror() on Windows at all? According to the Microsoft documentation, it is not thread safe, and WSAGetLastError() should be used instead.

[ndossche]

Interestingly, gai_strerror is MT-safe on glibc.

[cmb69]

Interestingly, gai_strerror is MT-safe on glibc.

POSIX isn't explicitly clear about this.

Anyhow, I still think we should go with this least intrusive patch for stable versions, and may have a closer look into this for the master branch (gai_strerror() is apparently supported on Windows even for IPv4 only, but the MT issue might need to be resolved).