Array.indexOf() returns -1 for negative integers which exist in arrays of length >= 48

[idkidk000]

Version: Deno 2.1.3

poc:

for (let value = -2; value < 2; value++) {
  for (let fill = -2; fill < 2; fill++) {
    if (value == fill) continue;
    for (let i = 0; i < 3; i++) {
      const length = 5 * Math.pow(10, i);
      const index = Math.floor(length / 2);
      const array = new Array(length).fill(fill);
      array[index] = value;
      const indexOf = array.indexOf(value);
      console.log({ value, fill, length, index, indexOf });
    }
  }
}

when run under node with:

docker run -it node node
.editor

[copy and paste poc code above]
[ctrl-d]
the index and indexOf always correctly match

when run under deno with:
docker run -it denoland/deno repl
[copy and paste poc code above]
indexOf is -1 when the array is of length>=50 and we're searching for an item whose value is a negative integer

find the array size at which the bug occurs:

for (let length = 5; length <= 50; length++) {
  const index = Math.floor(length / 2);
  const array = new Array(length).fill(0);
  array[index] = -1;
  const indexOf = array.indexOf(-1);
  console.log({ length, index, indexOf });
}

this works as expected under node but starts getting indexOf===-1 at length 48 in deno.

[dsherret]

Is this on windows? (is the docker container windows as well?)

[idkidk000]

tested locally on ubuntu and in docker. i don't have a windows machine available for testing.

[dsherret]

How did you install Deno?

[idkidk000]

using the installer curl -fsSL https://deno.land/install.sh | sh
but it's reproducible in the official deno docker container so it's not an install issue

[dsherret]

Sorry, last question, are you on x86 or aarch64? It's strange because I've been able to see weird behaviour on Windows, but nowhere else.

[idkidk000]

x86_64. a very old i5-3470 to be exact

[devsnek]

This looks like a bug in V8, could you please report it here: https://issues.chromium.org/issues/wizard

[Seally]

I went back through Deno official builds (Windows) and can confirm that this bug has existed since Deno v1.33.

I cannot reproduce on Deno v1.32.5 and earlier.