Regression: svelte:component with spread props loses static props

[PatrickG]

Describe the bug

It looks like #9006 introduced a bug.
When changing this and a spread props object, static props are not passed to the new component.
Also, it seems like the old spread props are passed to the new component first and then get changed to the new spread props.

Reproduction

https://svelte.dev/repl/c967016570194f1e90a1226132377e61?version=4.1.1
When clicking "page1" or "page2", it always should log "toto", instead undefined and "<Page2> was created without expected prop 'test'" is logged.

Also "<Page2> was created with unknown prop 'page1Prop'" is logged, which indicates the old spread props are passed to the new component.

REPL is working on version 4.1.0: https://svelte.dev/repl/c967016570194f1e90a1226132377e61?version=4.1.0

Logs

No response

System Info

REPL with Svelte 4.1.1

Severity

blocking an upgrade

[marianmeres]

I confirm similar strange behaviour on 4.2.0. I would classify it as a quite major bug.

REPL: https://svelte.dev/repl/1136dab3b7d642b7a429974c881057ae?version=4.2.0 (somewhat similar to above)

TL;DR: the two lines below behave differently

// doesn't work
<svelte:component this={component} {...props} {foo} />
// works
<svelte:component this={component} {...{...props, foo}} />

[BearToCode]

For your interest this works fine on the Svelte v5 Preview REPL.

[MrWaip]

I also faced the same problem.

Svelte version 4.2.8

[MrWaip]

Any update here? It's critical bug. Any dynamic forms are broken

[dummdidumm]

Fixed in Svelte 5