nodejs · trivikr · Jun 19, 2026
diff --git a/lib/internal/streams/iter/consumers.js b/lib/internal/streams/iter/consumers.js
@@ -39,6 +39,10 @@ const {
   validateObject,
 } = require('internal/validators');
 
+const {
+  markPromiseAsHandled,
+} = internalBinding('util');
+
 const {
   from,
   fromSync,
@@ -434,6 +438,20 @@ function merge(...args) {
       const ready = [];
       let activeCount = normalized.length;
       let waitResolve = null;
+      let onAbort;
+
+      if (signal) {
+        onAbort = () => {
+          if (waitResolve) {
+            waitResolve();
+            waitResolve = null;
+          }
+        };
+        signal.addEventListener('abort', onAbort, {
+          __proto__: null,
+          once: true,
+        });
+      }
 
       // Called when a source's .next() settles. Pushes the result into
       // the ready queue and wakes the consumer if it's waiting.
@@ -498,27 +516,43 @@ function merge(...args) {
           if (activeCount > 0) {
             await new Promise((resolve) => {
               waitResolve = resolve;
+              if (signal?.aborted) {
+                waitResolve = null;
+                resolve();
+              }
             });
           }
         }
       } catch (err) {
         primaryError = err;
       } finally {
+        if (onAbort !== undefined) {
+          signal.removeEventListener('abort', onAbort);
+        }
         // Clean up: return all iterators. Cleanup errors are not
         // swallowed - a broken iterator.return() (e.g., failing to
         // release a resource) should be visible to the caller.
-        await cleanupIterators(iterators, primaryError);
+        await cleanupIterators(
+          iterators,
+          primaryError,
+          signal?.aborted && primaryError === signal.reason,
+        );
       }
     },
   };
 }
 
-async function cleanupIterators(iterators, primaryError) {
+async function cleanupIterators(iterators, primaryError, skipAwaitCleanup) {
   let cleanupError;
   await SafePromiseAllReturnVoid(iterators, async (iterator) => {
     if (iterator.return) {
       try {
-        await iterator.return();
+        const result = iterator.return();
+        if (skipAwaitCleanup) {
+          markPromiseAsHandled(result);
+        } else {
+          await result;
+        }
       } catch (err) {
         // Keep the first cleanup error encountered.
         cleanupError ??= err;

diff --git a/test/parallel/test-stream-iter-consumers-merge.js b/test/parallel/test-stream-iter-consumers-merge.js
@@ -151,6 +151,25 @@ async function testMergeSignalMidIteration() {
   await assert.rejects(() => iter.next(), { name: 'AbortError' });
 }
 
+async function testMergeSignalDuringPendingMultiSourceRead() {
+  const ac = new AbortController();
+
+  async function* pending() {
+    await new Promise(() => {});
+    yield [];
+  }
+
+  const iter = merge(pending(), pending(), {
+    __proto__: null,
+    signal: ac.signal,
+  })[Symbol.asyncIterator]();
+
+  const next = iter.next();
+  ac.abort();
+
+  await assert.rejects(next, { name: 'AbortError' });
+}
+
 // merge() accepts string sources (normalized via from())
 async function testMergeStringSources() {
   const batches = [];
@@ -286,6 +305,7 @@ Promise.all([
   testMergeSourceError(),
   testMergeConsumerBreak(),
   testMergeSignalMidIteration(),
+  testMergeSignalDuringPendingMultiSourceRead(),
   testMergeStringSources(),
   testMergeObjectLikeSources(),
   testMergeCleanupErrorOnly(),