Possible regression in Node v12.11.0's Proxy

[alcuadrado]

• Version: v12.11.0
• process.versions:

process.versions
{
 node: '12.11.0',
 v8: '7.7.299.11-node.12',
 uv: '1.32.0',
 zlib: '1.2.11',
 brotli: '1.0.7',
 ares: '1.15.0',
 modules: '72',
 nghttp2: '1.39.2',
 napi: '5',
 llhttp: '1.1.4',
 http_parser: '2.8.0',
 openssl: '1.1.1c',
 cldr: '35.1',
 icu: '64.2',
 tz: '2019a',
 unicode: '12.1'
}

• Platform: Darwin pmbp 18.7.0 Darwin Kernel Version 18.7.0: Tue Aug 20 16:57:14 PDT 2019; root:xnu-4903.271.2~2/RELEASE_X86_64 x86_64
• Subsystem: V8

Running this in node v12.11.0 fails:

Object.getPrototypeOf(new Proxy(Object.create(null), {
 getPrototypeOf(target) {
 return Reflect.getPrototypeOf(target)
 }
}))

Pasting it in node's REPL gives this error:

Thrown:
TypeError: 'getPrototypeOf' on proxy: trap returned neither object nor null
 at Function.getPrototypeOf (<anonymous>)

Expected behavior: it should just print null.

[alcuadrado]

Running it with v12.10.0 works just fine.

[addaleax]

@nodejs/v8

[alcuadrado]

BTW, this bug is also present in Chrome 77, and not in Chrome 76.

PS: Reported it to v8 https://bugs.chromium.org/p/v8/issues/detail?id=9781

[Hakerh400]

Bisected to v8/v8@4e17a6b

[targos]

Just confirming that Chrome 78 (beta) and 79 (canary) are also affected.

[tcf909]

Is 12.x going to support the fix in v8 7.8? (thought I read some place the 12.x branches floating patch was only through 7.7)

Anything we can do in the meantime without waiting for a full v8 7.8 release (which the v8 fix is slated for)?

[targos]

@tcf909 can you point me to the fix that is in V8 7.8?

[hashseed]

@schuay @verwaest

[tcf909]

@targos https://bugs.chromium.org/p/v8/issues/detail?id=9781

If you look at the tags it is tagged merge-request-78

[tcf909]

Also, since this is so core, might be nice to have a test in the future to smooth out v8 changes in the lts branch.