[bug] Crash on Windows when turning off window decorations from synchronous command.

[Themayu]

Describe the bug

When calling tauri::Window::set_decorations(&self, false) from a synchronous command on Windows, as in the reproduction code provided below, the application hangs right after turning off decorations before exiting with code 0xCFFFFFFF. Executing the provided reproduction code in an asynchronous command finishes it successfully, with no crash.

Reproduction

The crash can be reproduced with the following command:

#[tauri::command]
pub fn settings_toggle_decorations(window: Window) -> Result<(), ()> {
    window.set_decorations(false);

    Ok(())
}

Executing this command will immediately cause the application to hang before exiting to Windows with no panic message.

(EDIT: apparently blocking_kind doesn't exist for &Result<(), Infallible>, so the return type has been changed to Result<(), ()>)

Expected behavior

The window's decorations are removed and the application continues normally, without crashing.

Platform and versions

cargo tauri info

Environment
  › OS: Windows 10.0.19043 X64
  › Webview2: 102.0.1245.41
  › MSVC: 
      - Visual Studio Enterprise 2019
  › Node.js: 15.3.0
  › npm: 6.14.2
  › pnpm: Not installed!
  › yarn: Not installed!
  › rustup: 1.24.3
  › rustc: 1.63.0-nightly
  › cargo: 1.63.0-nightly
  › Rust toolchain: nightly-x86_64-pc-windows-msvc 

Packages
  › @tauri-apps/cli [NPM]: 1.0.0
  › @tauri-apps/api [NPM]: 1.0.1
  › tauri [RUST]: 1.0.0 (no lockfile),
  › tauri-build [RUST]: no manifest (no lockfile),
  › tao [RUST]: no manifest (no lockfile),
  › wry [RUST]: no manifest (no lockfile),

App
  › build-type: build
  › CSP: default-src blob: data: filesystem: ws: wss: http: https: tauri: 'unsafe-eval' 'unsafe-inline' 'self' img-src: 'self'
  › distDir: ../dist
  › devPath: http://localhost:10001/
  › bundler: Rollup

App directory structure
  ├─ .cargo
  ├─ .git
  ├─ .vscode
  ├─ dist
  ├─ node_modules
  ├─ src
  ├─ src-common
  ├─ src-macros
  ├─ src-signals
  ├─ src-tauri
  └─ target

Stack trace

Not applicable; application exits with no stack trace. Exit code is 0xCFFFFFFF.

Additional context

This used to work fine in a beta version of tauri; though I can't remember which beta version this was. Possible regression?

[lucasfernog]

Thanks for the report. Will be fixed in the next release.