reset_focus crashes on invalid CSS selectors in URL hash

[taasan]

Describe the bug

I have some routes where I store application data encoded in the URL hash (not for routing). When the data is gzipped with a gzip: prefix, SvelteKit's reset_focus function crashes because it tries to call document.querySelector(location.hash) with an invalid CSS selector.

kit/packages/kit/src/runtime/client/client.js

Line 2804 in 5594597

if (!app.hash && location.hash && document.querySelector(location.hash)) {

Reproduction

https://github.com/taasan/sveltekit-reset-focus-bug/

Logs

Edit: replaced firefox backtrace, which was a mile long, with the chrome stacktrace

Uncaught (in promise) SyntaxError: Failed to execute 'querySelector' on 'Document': '#gzip:H4sIAAAAAAAAA0sqTQcAFL+MNQMAAAA=' is not a valid selector.
    at reset_focus (client.js?v=2915ee31:2804:46)

System Info

System:
    OS: Linux 6.14 Fedora Linux 42 (Workstation Edition)
    CPU: (8) x64 Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz
    Memory: 19.58 GB / 31.09 GB
    Container: Yes
    Shell: 5.9 - /usr/bin/zsh
  Binaries:
    Node: 22.16.0 - /usr/bin/node
    npm: 10.9.2 - /usr/bin/npm
  Browsers:
    Chrome: 137.0.7151.68
  npmPackages:
    @sveltejs/adapter-auto: ^6.0.0 => 6.0.1 
    @sveltejs/kit: ^2.16.0 => 2.21.4 
    @sveltejs/vite-plugin-svelte: ^5.0.0 => 5.1.0 
    svelte: ^5.0.0 => 5.33.19 
    vite: ^6.2.6 => 6.3.5

Severity

annoyance

Additional Information

No response