Add support for `sockaddr_un` on Windows. (#6513)

* Windows: Fix warning about undefined if_indextoname()

* Windows: Fix UNIXSocket on MINGW and make .pair more reliable

* Windows: Use nonblock=true for read tests with scheduler

* Windows: Move socket detection from File.socket? to File.stat

Add S_IFSOCK to Windows and interpret reparse points accordingly.
Enable tests that work now.

* Windows: Use wide-char functions to UNIXSocket

This fixes behaviour with non-ASCII characters.
It also fixes deletion of temporary UNIXSocket.pair files.

* Windows: Add UNIXSocket tests for specifics of Windows impl.

* Windows: fix VC build due to missing _snwprintf

Avoid usage of _snwprintf, since it fails linking ruby.dll like so:

  linking shared-library x64-vcruntime140-ruby320.dll
  x64-vcruntime140-ruby320.def : error LNK2001: unresolved external symbol snwprintf
  x64-vcruntime140-ruby320.def : error LNK2001: unresolved external symbol vsnwprintf_l

whereas linking miniruby.exe succeeds.

This patch uses snprintf on the UTF-8 string instead.

Also remove branch GetWindowsDirectoryW, since it doesn't work.

* Windows: Fix dangling symlink test failures

Co-authored-by: Lars Kanis <kanis@comcard.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/win32/file.h b/win32/file.h
index ef701487dd..4f1f36a75c 100644
--- a/win32/file.h
+++ b/win32/file.h
@@ -1,6 +1,10 @@
 #ifndef RUBY_WIN32_FILE_H
 #define RUBY_WIN32_FILE_H
 
+#ifndef IO_REPARSE_TAG_AF_UNIX
+# define IO_REPARSE_TAG_AF_UNIX 0x80000023
+#endif
+
 enum {
     MINIMUM_REPARSE_BUFFER_PATH_LEN = 100
 };