Select multiple value does not get set with spread props

[nathancahill]

Describe the bug

This works:

<script>
  let value = ['Hello', 'World'];
</script>

<select multiple {value}>
  <option>Hello</option>
  <option>World</option>
</select>

Adding any type of spread, even an empty object {...{}}, causes the value not to be set:

<script>
  let value = ['Hello', 'World'];
</script>

<select multiple {value} {...{}}>
  <option>Hello</option>
  <option>World</option>
</select>

Logs
No logs.

To Reproduce
https://svelte.dev/repl/99bd5ebecc464e328972252e287ab716?version=3.18.1

Expected behavior
The <select multiple> value should be set.

Stacktraces
No stacktrace.

Information about your Svelte project:

• Your browser and the version: Firefox 72, Chrome 80, Safari 13

• Your operating system: OS X 10.14.6

• Svelte version: 3.18.1

• Rollup

Severity
Mildly annoying, needed to build a complex workaround for a simple thing.

Additional Context
Further debugging, it seems like the issue might be related to this line in Element/Binding.ts#L212

The check is node.get_static_attribute_value('multiple') === true. Adding a spread causes this check fail.

[Conduitry]

I believe this is another manifestation of #3680 and that both could be fixed together.

[Conduitry]

This is fixed in 3.23.0 - https://svelte.dev/repl/99bd5ebecc464e328972252e287ab716?version=3.23.0

[nathancahill]

Awesome!