src: ReadIterable entries may be empty

nodejs · Oct 25, 2023 · ee40112 · ee40112
1 parent c3a41d8
commit ee40112
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Showing 3 changed files with 28 additions and 2 deletions.
diff --git a/src/node_messaging.cc b/src/node_messaging.cc
@@ -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);
 }
 

diff --git a/test/parallel/test-messagechannel.js b/test/parallel/test-messagechannel.js
@@ -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());
diff --git a/test/parallel/test-structuredClone-global.js b/test/parallel/test-structuredClone-global.js
@@ -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.strictEqual(cloned, {});
+}