stream: uncork fromWritable writev on chunk error

Ensure fromWritable().writev() uncorks the wrapped Writable when
converting a later chunk throws. This prevents an internal cork from
leaking after ERR_INVALID_ARG_TYPE.

Fixes: #63294

Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com>
Assisted-by: openai:gpt-5.5
PR-URL: #63295
Fixes: #63294
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ethan Arrowood <ethan@arrowood.dev>

Author: trivikr

lib/internal/streams/iter/classic.js

@@ -535,6 +535,16 @@ function fromWritable(writable, options = kNullPrototype) {
     return (writable.writableLength ?? 0) >= hwm;
   }
 
+  function writeChunks(chunks) {
+    let ok = true;
+    for (let i = 0; i < chunks.length; i++) {
+      const bytes = toUint8Array(chunks[i]);
+      totalBytes += TypedArrayPrototypeGetByteLength(bytes);
+      ok = writable.write(bytes);
+    }
+    return ok;
+  }
+
   const writer = {
     __proto__: null,
 
@@ -630,14 +640,18 @@ function fromWritable(writable, options = kNullPrototype) {
         return PromiseResolve();
       }
 
-      if (typeof writable.cork === 'function') writable.cork();
       let ok = true;
-      for (let i = 0; i < chunks.length; i++) {
-        const bytes = toUint8Array(chunks[i]);
-        totalBytes += TypedArrayPrototypeGetByteLength(bytes);
-        ok = writable.write(bytes);
+      if (typeof writable.cork === 'function' &&
+          typeof writable.uncork === 'function') {
+        writable.cork();
+        try {
+          ok = writeChunks(chunks);
+        } finally {
+          writable.uncork();
+        }
+      } else {
+        ok = writeChunks(chunks);
       }
-      if (typeof writable.uncork === 'function') writable.uncork();
 
       if (ok) return PromiseResolve();
 

test/parallel/test-stream-iter-writable-interop.js

@@ -550,6 +550,21 @@ function testWritevInvalidChunksType() {
   );
 }
 
+// =============================================================================
+// writev() uncorks when chunk validation throws
+// =============================================================================
+
+function testWritevInvalidChunkUncorks() {
+  const writable = new Writable({ write(chunk, enc, cb) { cb(); } });
+  const writer = fromWritable(writable);
+
+  assert.throws(
+    () => writer.writev([new Uint8Array([1]), 42]),
+    { code: 'ERR_INVALID_ARG_TYPE' },
+  );
+  assert.strictEqual(writable.writableCorked, 0);
+}
+
 // =============================================================================
 // Cached writer: second call returns same instance
 // =============================================================================
@@ -638,6 +653,7 @@ testDrainableNull();
 testDropOldestThrows();
 testInvalidBackpressureThrows();
 testWritevInvalidChunksType();
+testWritevInvalidChunkUncorks();
 testCachedWriter();
 testObjectModeThrows();