From 4f76b9535da02b6b2ffd8c88787cecff644149ed Mon Sep 17 00:00:00 2001
From: asiva <asiva@google.com>
Date: Mon, 4 Apr 2022 21:34:21 +0000
Subject: [PATCH] [VM / IO] Assert When a socket exception is being thrown with
 an error code of 0.

TEST=ci

Change-Id: Ie0ea5329dfe0307f47fc04db693dae4e352d0f64
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/239846
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Siva Annamalai <asiva@google.com>
---
 runtime/bin/socket.cc                      | 13 ++++++++++++-
 sdk/lib/_internal/vm/bin/socket_patch.dart | 16 +++++++++++-----
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/runtime/bin/socket.cc b/runtime/bin/socket.cc
index 21bfadf3cff..708bda49461 100644
--- a/runtime/bin/socket.cc
+++ b/runtime/bin/socket.cc
@@ -914,7 +914,18 @@ void FUNCTION_NAME(Socket_GetError)(Dart_NativeArguments args) {
       Socket::GetSocketIdNativeField(Dart_GetNativeArgument(args, 0));
   OSError os_error;
   SocketBase::GetError(socket->fd(), &os_error);
-  Dart_SetReturnValue(args, DartUtils::NewDartOSError(&os_error));
+  if (os_error.code() != 0) {
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError(&os_error));
+  } else {
+    Dart_SetReturnValue(args, Dart_Null());
+  }
+}
+
+void FUNCTION_NAME(Socket_Fatal)(Dart_NativeArguments args) {
+  Dart_Handle msg = Dart_GetNativeArgument(args, 0);
+  const char* msgStr =
+      (!Dart_IsNull(msg)) ? DartUtils::GetStringValue(msg) : nullptr;
+  FATAL("Fatal error in dart:io (socket): %s", msgStr);
 }
 
 void FUNCTION_NAME(Socket_GetFD)(Dart_NativeArguments args) {
diff --git a/sdk/lib/_internal/vm/bin/socket_patch.dart b/sdk/lib/_internal/vm/bin/socket_patch.dart
index 7c9925a83c2..d0bddf85fbf 100644
--- a/sdk/lib/_internal/vm/bin/socket_patch.dart
+++ b/sdk/lib/_internal/vm/bin/socket_patch.dart
@@ -877,8 +877,8 @@ class _NativeSocket extends _NativeSocketNativeWrapper with _ServiceObject {
         // the SO_ERROR option at level SOL_SOCKET to determine whether
         // connect() completed successfully (SO_ERROR is zero) or
         // unsuccessfully.
-        final OSError osError = socket.nativeGetError();
-        if (osError.errorCode != 0) {
+        final osError = socket.nativeGetError();
+        if (osError != null) {
           socket.close();
           error ??= osError;
           connectNext();
@@ -1404,8 +1404,12 @@ class _NativeSocket extends _NativeSocketNativeWrapper with _ServiceObject {
 
         if (i == errorEvent) {
           if (!isClosing) {
-            final err = nativeGetError();
-            reportError(err, null, err.message);
+            final osError = nativeGetError();
+            if (osError == null) {
+              _nativeFatal("Reporting error with OSError code of 0");
+            } else {
+              reportError(osError, null, osError.message);
+            }
           }
         } else if (!isClosed) {
           // If the connection is closed right after it's accepted, there's a
@@ -1688,7 +1692,7 @@ class _NativeSocket extends _NativeSocketNativeWrapper with _ServiceObject {
   @pragma("vm:external-name", "Socket_GetFD")
   external int get fd;
   @pragma("vm:external-name", "Socket_GetError")
-  external OSError nativeGetError();
+  external OSError? nativeGetError();
   @pragma("vm:external-name", "Socket_GetOption")
   external nativeGetOption(int option, int protocol);
   @pragma("vm:external-name", "Socket_GetRawOption")
@@ -1703,6 +1707,8 @@ class _NativeSocket extends _NativeSocketNativeWrapper with _ServiceObject {
   @pragma("vm:external-name", "Socket_LeaveMulticast")
   external void nativeLeaveMulticast(
       Uint8List addr, Uint8List? interfaceAddr, int interfaceIndex);
+  @pragma("vm:external-name", "Socket_Fatal")
+  external static void _nativeFatal(msg);
 }
 
 class _RawServerSocket extends Stream<RawSocket> implements RawServerSocket {