consumePush crashes when chunk arrives after body.json() teardown

[akaNightmare]

Bug Description

Calling body.json() (or other consume helpers) and then tearing down the stream (abort/timeout/close) runs consumeFinish(), which sets consume.body = null. stream[kConsume] is left in place.
If BodyReadable.push() runs after that - for example a late chunk from the decompress interceptor- it still calls consumePush(), which does consume.body.push(chunk) and throws:

TypeError: Cannot read properties of null (reading 'push')
    at consumePush (lib/api/readable.js:549)

This is a synchronous throw, not the AbortError from the .json() promise.

Reproducible By

const { Readable: BodyReadable } = require('undici/lib/api/readable');

describe('undici BodyReadable consume race', () => {
    it('must throw when a chunk arrives after consume teardown', async () => {
        const body = new BodyReadable({ resume: () => {}, abort: () => {} });
        const jsonPromise = body.json();

        await new Promise(resolve => queueMicrotask(resolve));

        body.emit('close');

        expect(() => body.push(Buffer.from('late chunk'))).toThrow(/Cannot read properties of null \(reading 'push'\)/);

        await expect(jsonPromise).rejects.toMatchObject({ name: 'AbortError' });
    });
});

in real usage: request() + interceptors.decompress(), body.json() with a short AbortSignal timeout while the response is still streaming

Expected Behavior

Late chunks after consume teardown should be dropped. .json() should reject with AbortError only - no extra sync crash.

Logs & Screenshots

TypeError: Cannot read properties of null (reading 'push')
    at consumePush (/.../undici/lib/api/readable.js:549:16)
    at BodyReadable.push (/.../undici/lib/api/readable.js:160:9)

Environment

• undici 7.27.0
• Node.js v24.12.0
• macOS / Linux, HTTP/1.1
• Agent.compose(interceptors.decompress())

Additional context

Looks related to #4880 (null guard for late push after H2 teardown). consumePush has no similar guard.

[mcollina]

Thanks for reporting!

Can you provide steps to reproduce? We often need a reproducible example, e.g. some code that allows someone else to recreate your problem by just copying and pasting it using public APIs. If it involves more than a couple of different file, create a new repository on GitHub and add a link to that.