stream: fix multiple Writable.destroy() calls

Calling Writable.destroy() multiple times in the same tick
could cause an assertion error.

Fixes: #38189

PR-URL: #38221
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Nitzan Uziely <linkgoron@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

lib/internal/streams/writable.js

@@ -57,7 +57,6 @@ const {
   getHighWaterMark,
   getDefaultHighWaterMark
 } = require('internal/streams/state');
-const assert = require('internal/assert');
 const {
   ERR_INVALID_ARG_TYPE,
   ERR_METHOD_NOT_IMPLEMENTED,
@@ -854,11 +853,9 @@ Writable.prototype.destroy = function(err, cb) {
   const state = this._writableState;
 
   // Invoke pending callbacks.
-  if (
-    state.bufferedIndex < state.buffered.length ||
-    state[kOnFinished].length
-  ) {
-    assert(!state.destroyed);
+  if (!state.destroyed &&
+    (state.bufferedIndex < state.buffered.length ||
+      state[kOnFinished].length)) {
     process.nextTick(errorBuffer, state);
   }
 

test/parallel/test-stream-writable-destroy.js

@@ -460,3 +460,14 @@ const assert = require('assert');
     assert.strictEqual(write.destroyed, true);
   }));
 }
+
+{
+  // Destroy twice
+  const write = new Writable({
+    write(chunk, enc, cb) { cb(); }
+  });
+
+  write.end(common.mustCall());
+  write.destroy();
+  write.destroy();
+}