After this patch curl requires targeting Vista or newer, and a toolchain
with Vista support.
Supported MSVC compilers (VS2010+) all support Vista:
- VS2012+ target Win8 (or later) by default.
- VS2010 targets Win7 by default.
Supported mingw-w64 versions (v3+) all support Vista:
- mingw-w64 v9+ target Win10 by default.
- mingw-w64 v8 and older target Server 2003 (~XP) by default.
After this patch it may be necessary to override the default Windows
target version to Vista (or newer) via:
autotools: `CPPFLAGS=-D_WIN32_WINNT=0x0600`
cmake: `-DCURL_TARGET_WINDOWS_VERSION=0x0600`
- mingw-w64 v6+ allow changing the default at toolchain build-time.
Notes:
- For non-MSVC, non-mingw-w64 toolchains, `if_nametoindex` needs to be
allowlisted in `curl_setup.h`, if they do support it.
Fixes#17985 (discussion)
Closes#18009