Form spread with a remote function doesn't include data on the submit button in the request

[peterreeves]

Describe the bug

Forms that have a name & value pair on the submit button don't seem to include the data if the form function is spread into the form, but it works if you specify the method and action.

Reproduction

https://stackblitz.com/edit/stackblitz-webcontainer-api-starter-xmm4jmhs?file=src%2Froutes%2F%2Bpage.svelte

Clicking "Delete A" shows a validation error.
Clicking "Delete B" works, and prints a message on the server console.

Logs

System Info

System:
    OS: Windows 11 10.0.26100
    CPU: (24) x64 AMD Ryzen 9 5900X 12-Core Processor
    Memory: 15.56 GB / 31.91 GB
  Binaries:
    Node: 22.17.1 - C:\Program Files\nodejs\node.EXE
    npm: 11.5.2 - C:\Program Files\nodejs\npm.CMD
    pnpm: 8.15.5 - ~\AppData\Local\pnpm\pnpm.CMD
  Browsers:
    Edge: Chromium (140.0.3485.54)
    Internet Explorer: 11.0.26100.1882
  npmPackages:
    @sveltejs/adapter-node: ^5.2.13 => 5.2.13
    @sveltejs/adapter-static: ^3.0.8 => 3.0.8
    @sveltejs/kit: ^2.26.1 => 2.26.1
    @sveltejs/vite-plugin-svelte: ^6.1.0 => 6.1.0
    svelte: ^5.36.17 => 5.38.5
    vite: ^7.0.6 => 7.0.6

Severity

annoyance

Additional Information

No response

[andreasbhansen]

@peterreeves It seems that adding {...formActionName.buttonProps} [docs] to the submit button does the trick.
Here's a forked example: https://stackblitz.com/edit/stackblitz-webcontainer-api-starter-nrxbufh8?file=src%2Froutes%2F%2Bpage.svelte