nodejs
diff --git a/‎src/node_messaging.cc‎
Lines changed: 5 additions & 2 deletions b/‎src/node_messaging.cc‎
Lines changed: 5 additions & 2 deletions
diff --git a/‎test/parallel/test-messagechannel.js‎
Lines changed: 12 additions & 0 deletions b/‎test/parallel/test-messagechannel.js‎
Lines changed: 12 additions & 0 deletions
diff --git a/‎test/parallel/test-structuredClone-global.js‎
Lines changed: 11 additions & 0 deletions b/‎test/parallel/test-structuredClone-global.js‎
Lines changed: 11 additions & 0 deletions
@@ -1003,8 +1003,11 @@ static Maybe<bool> ReadIterable(Environment* env,
     entries.push_back(val);
   }
 
-  transfer_list.AllocateSufficientStorage(entries.size());
-  std::copy(entries.begin(), entries.end(), &transfer_list[0]);
+  if (!entries.empty()) {
+    transfer_list.AllocateSufficientStorage(entries.size());
+    std::copy(entries.begin(), entries.end(), &transfer_list[0]);
+  }
+
   return Just(true);
 }
 
 
@@ -0,0 +1,12 @@
+'use strict';
+
+const common = require('../common');
+
+// See: https://github.com/nodejs/node/issues/49940
+(async () => {
+  new MessageChannel().port1.postMessage({}, {
+    transfer: {
+      *[Symbol.iterator]() {}
+    }
+  });
+})().then(common.mustCall());
@@ -15,3 +15,14 @@ assert.strictEqual(structuredClone(undefined, null), undefined);
 // Transfer can be null or undefined.
 assert.strictEqual(structuredClone(undefined, { transfer: null }), undefined);
 assert.strictEqual(structuredClone(undefined, { }), undefined);
+
+{
+  // See: https://github.com/nodejs/node/issues/49940
+  const cloned = structuredClone({}, {
+    transfer: {
+      *[Symbol.iterator]() {}
+    }
+  });
+
+  assert.deepStrictEqual(cloned, {});
+}
Original file line number	Diff line number	Diff line change
@@ -1003,8 +1003,11 @@ static Maybe<bool> ReadIterable(Environment* env,
1003	1003	entries.push_back(val);
1004	1004	}
1005	1005
1006		- transfer_list.AllocateSufficientStorage(entries.size());
1007		- std::copy(entries.begin(), entries.end(), &transfer_list[0]);
	1006	+ if (!entries.empty()) {
	1007	+ transfer_list.AllocateSufficientStorage(entries.size());
	1008	+ std::copy(entries.begin(), entries.end(), &transfer_list[0]);
	1009	+ }
	1010	+
1008	1011	return Just(true);
1009	1012	}
1010	1013