fix: end a zip directory entry through flow control, not a timer

The directory placeholder emitted 'end' from a setImmediate, so the event
fired whether or not the consumer had finished with the entry. A listener
that creates the directory asynchronously would therefore be handed the next
entry, a file inside that directory, before the directory existed, and the
write failed with ENOENT.

That is the intermittent "ENOENT ... /xxx/bar.txt" seen in
test/zip/uncompress_stream.test.js on loaded CI runners. Reproduces every
time by delaying the mkdir in the entry handler.

Push EOF instead, so 'end' arrives only once the consumer reads or resumes
the entry and the ordering no longer depends on timing.

Author: fengmk2

lib/zip/uncompress_stream.js

@@ -125,7 +125,11 @@ class ZipUncompressStream extends UncompressBaseStream {
           const placeholder = new stream.Readable({ read() {} });
           debug('directory, header: %j', header);
           this.emit('entry', header, placeholder, next);
-          setImmediate(() => placeholder.emit('end'));
+          // Push EOF rather than emitting 'end' on a timer: a fabricated event fires
+          // whether or not the consumer has finished with the entry, so a listener
+          // that creates the directory asynchronously would see the next entry, a
+          // file inside that directory, arrive before the directory exists.
+          placeholder.push(null);
         }
       })
       .on('end', () => this._finalCallback())