stream: avoid writing to writable

A remainder from a previous refactoring.

Refs: #31197

PR-URL: #31805
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/_stream_writable.js

@@ -687,7 +687,6 @@ function endWritable(stream, state, cb) {
       onFinished(stream, state, cb);
   }
   state.ended = true;
-  stream.writable = false;
 }
 
 function onCorkedFinish(corkReq, state, err) {
@@ -741,7 +740,7 @@ ObjectDefineProperties(Writable.prototype, {
     get() {
       const w = this._writableState;
       if (!w) return false;
-      if (w.writable !== undefined) return w.writable;
+      if (w.writable !== undefined) return w.writable && !w.ended;
       return Boolean(!w.destroyed && !w.errored && !w.ending);
     },
     set(val) {

test/parallel/test-stream-writable-ended-state.js

@@ -9,17 +9,24 @@ const writable = new stream.Writable();
 
 writable._write = (chunk, encoding, cb) => {
   assert.strictEqual(writable._writableState.ended, false);
+  assert.strictEqual(writable._writableState.writable, undefined);
   assert.strictEqual(writable.writableEnded, false);
   cb();
 };
 
 assert.strictEqual(writable._writableState.ended, false);
+assert.strictEqual(writable._writableState.writable, undefined);
+assert.strictEqual(writable.writable, true);
 assert.strictEqual(writable.writableEnded, false);
 
 writable.end('testing ended state', common.mustCall(() => {
   assert.strictEqual(writable._writableState.ended, true);
+  assert.strictEqual(writable._writableState.writable, undefined);
+  assert.strictEqual(writable.writable, false);
   assert.strictEqual(writable.writableEnded, true);
 }));
 
 assert.strictEqual(writable._writableState.ended, true);
+assert.strictEqual(writable._writableState.writable, undefined);
+assert.strictEqual(writable.writable, false);
 assert.strictEqual(writable.writableEnded, true);