$_FILES array with multiple file uploads

[stoph]

Normal single uploads via name="photo" seem to work, but when you enable multiple by using name="photos[]" (but still only upload one file) the $_FILES array looks to be inverted.

Array
(
  [photos] => Array
    (
      [0] => Array
        (
          [name] => logo.png
        )

      [1] => Array
        (
          [tmp_name] => /tmp/0.71939801482611698269
        )

      [2] => Array
        (
          [type] => image/png
        )

      [3] => Array
        (
          [error] => 0
        )

      [4] => Array
        (
          [size] => 8192
        )
    )
)

It should be [photos][name][0] not [photos][0][name]

Array
(
  [photos] => Array
    (
      [name] => Array
        (
          [0] => logo.png
        )

      [tmp_name] => Array
        (
          [0] => /tmp/0.71939801482611698269
        )

      [type] => Array
        (
          [0] => image/png
        )

      [error] => Array
        (
          [0] => 0
        )

      [size] => Array
        (
          [0] => 8192
        )
    )
)

And related, when I try to upload more than one file at a time, the browser hangs as (pending) with this error from wp-now.

Trace: TypeError: Cannot read properties of undefined (reading 'buffer')
    at Object.arrayBuffer (file:///Users/christoph/.nvm/versions/node/v20.8.1/lib/node_modules/@wp-now/wp-now/main.js:894:46)
    at #dispatchToPHP (/Users/christoph/.nvm/versions/node/v20.8.1/lib/node_modules/@wp-now/wp-now/node_modules/@php-wasm/node/index.cjs:68550:45)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async PHPRequestHandler.request (/Users/christoph/.nvm/versions/node/v20.8.1/lib/node_modules/@wp-now/wp-now/node_modules/@php-wasm/node/index.cjs:68484:14)
    at async PHPBrowser.request (/Users/christoph/.nvm/versions/node/v20.8.1/lib/node_modules/@wp-now/wp-now/node_modules/@php-wasm/node/index.cjs:68326:22)
    at file:///Users/christoph/.nvm/versions/node/v20.8.1/lib/node_modules/@wp-now/wp-now/main.js:908:15
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

[bgrgicak]

@stoph @adamziel what would be a good way to recreate this?
I can try writing some tests, but I would still like to have a way to test it on the site.

[stoph]

I created a super simple plugin to echo the array after an upload.

If you upload one file, it'll show the (inverted) array. It fails on multiple uploads though. To see that error, I was testing locally on wp-now and viewing the wp-now start terminal output. You can download the plugin here)