[bug] multiwebview example stops resizing

[happybeing]

Describe the bug

I'm using the multiwebview example to integrate a Webview into my app in place of an iframe and having just added a single Webview based on the example code found strange behaviour when resizing the main app window. So I tried the example and it does the same.

The multiwebview example runs and I can resize the main window, but after a few times of widening and narrowing the main window, the Webview content stops resizing and remains a fixed width. This applies equally to all three embedded Webviews.

They do though continue to adjust to changes in the height of the main window.

While trying this out a few times it crashed the Gnome desktop and forced a logout.

Reproduction

Run the example:

cargo run --example multiwebview --features=unstable

Wait until the external content has loaded.

Drag the bottom right corner of the main app window right then left, repeatedly.

After about half a dozen times, the Webviews no longer follow the right hand edge, but remain at a fixed width. They do though continue to adjust to changes in the height of the main window.

Expected behavior

Webviews and their content should continue to resize as I resize the "main" app window.

Full tauri info output

$ cargo tauri info
warning: `/home/mrh/src/safe-browser/tauri-tauri-v2.0.0-beta.0/.cargo/config` is deprecated in favor of `config.toml`
note: if you need to support cargo 1.38 or earlier, you can symlink `config` to `config.toml`

[✔] Environment
    - OS: Ubuntu 24.4.0 X64
    ✔ webkit2gtk-4.1: 2.44.0
    ✔ rsvg2: 2.58.0
    ✔ rustc: 1.79.0 (129f3b996 2024-06-10)
    ✔ cargo: 1.79.0 (ffa9cf99a 2024-06-03)
    ✔ rustup: 1.27.1 (54dd3d00f 2024-04-24)
    ✔ Rust toolchain: stable-x86_64-unknown-linux-gnu (environment override by RUSTUP_TOOLCHAIN)
    - node: 22.1.0
    - npm: 10.7.0

[-] Packages
    - tauri [RUST]: 2.0.0-beta.0 (no manifest)
    - tauri-build [RUST]: 2.0.0-beta.0 (no manifest)
    - wry [RUST]: 0.35.2 (no manifest)
    - tao [RUST]: 0.25.0 (no manifest)
    - tauri-cli [RUST]: 2.0.0-beta.20
    - @tauri-apps/api : not installed!
    - @tauri-apps/cli [NPM]: 2.0.0-beta.20

[-] App
    - build-type: bundle
    - CSP: default-src 'self'; connect-src ipc: http:https://ipc.localhost
    - frontendDist: ["index.html"]
    - framework: Svelte
    - bundler: Vite

Stack trace

No response

Additional context

No response

EDITS

Inspecting the main Tauri window I notice there are errors in the Web console:

SyntaxError: Unexpected token ';'

Followed my a large number of this error:

Unhandled Promise Rejection: TypeError: window.__TAURI_INTERNALS__.postMessage is not a function. (In 'window.__TAURI_INTERNALS__.postMessage(message)', 'window.__TAURI_INTERNALS__.postMessage' is undefined)