Reapply "[vm/win] Use wide-character api for local hostname on Windows."

This relands a fix for looking up hostname on Windows in utf8-aware fashion. Previously this was reverted because the API was only introduced in Windows 8, making this use of Windows API fail on Windows 7. With Windows 7 no longer being a target, original fix can be relanded. BUG=#52701 TEST=manually Change-Id: I330048c8b92ce805b7bb7e3fa05c88fefe3a30b0 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/353500 Reviewed-by: Siva Annamalai <[email protected]> Commit-Queue: Alexander Aprelev <[email protected]>
dart-lang · Feb 21, 2024 · 35c6cc6 · 35c6cc6
1 parent ec4dd93
commit 35c6cc6
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/runtime/bin/platform_win.cc b/runtime/bin/platform_win.cc
@@ -218,7 +218,14 @@ bool Platform::LocalHostname(char* buffer, intptr_t buffer_length) {
   if (!SocketBase::Initialize()) {
     return false;
   }
-  return gethostname(buffer, buffer_length) == 0;
+  // 256 is max length per https://learn.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-gethostnamew#remarks
+  const int HOSTNAME_MAXLENGTH = 256;
+  wchar_t hostname_w[HOSTNAME_MAXLENGTH];
+  if (GetHostNameW(hostname_w, HOSTNAME_MAXLENGTH) != 0) {
+    return false;
+  }
+  return WideCharToMultiByte(CP_UTF8, 0, hostname_w, -1, buffer, buffer_length,
+                             nullptr, nullptr) != 0;
 #endif
 }