Readable stops reading

[lpinca]

• Version: >= 10.0.0
• Platform: any
• Subsystem: stream

Consider the following example, born from discussion in #25969.

const { Readable } = require('stream');

const buf = Buffer.alloc(8192);

const readable = new Readable({
  read() {
    this.push(buf);
  }
});

readable.on('readable', function() {
  const data = readable.read();
  console.log(data.length);
});

Note that readable.read() is not called in a loop on purpose.

Expected behavior

An endless loop. This works as expected in Node.js < 10.0.0.

Actual behavior

Reading stops after a few reads.

---

Bisecting points to this commit: 0778f79.

[targos]

@nodejs/streams

[mcollina]

Fixed in cd302d7.