[bug] "decorations": false inconsistent on macos and windows

[abdullahqusim]

Describe the bug

When setting "decorations": false in the tauri.conf.json file, macos and windows exhibit inconsistent behaviour. On windows, only the titlebar appears to be missing. On macos, both the titlebar and the window's rounded borders are missing.

I've managed to work around this issue by using tauri.[platform].conf.json. I have also managed to work around it by setting the window to transparent and then using a white background on body with border radius, but I'm not sure if it matches the native platform's style.

Regardless, I feel like this config option should do the same thing on both platforms.

macos:

windows:

Reproduction

tauri.conf.json

"windows": [
  {
    "title": "main",
    "width": 800,
    "height": 600,
    "decorations": false
  }
],

Expected behavior

For consistent behaviour to be exhibited on both platforms.

Full tauri info output

[✔] Environment
    - OS: Windows 10.0.22631 x86_64 (X64)
    ✔ WebView2: 131.0.2903.112
    ✔ MSVC: Visual Studio Community 2022
    ✔ rustc: 1.83.0 (90b35a623 2024-11-26)
    ✔ cargo: 1.83.0 (5ffbef321 2024-10-29)
    ✔ rustup: 1.27.1 (54dd3d00f 2024-04-24)
    ✔ Rust toolchain: stable-x86_64-pc-windows-msvc (environment override by RUSTUP_TOOLCHAIN)
    - bun: 1.1.20

[-] Packages
    - tauri 🦀: 2.1.1
    - tauri-build 🦀: 2.0.3
    - wry 🦀: 0.47.2
    - tao 🦀: 0.30.8
    - tauri-cli 🦀: 2.1.0

[-] Plugins
    - tauri-plugin-shell 🦀: 2.0.2

[-] App
    - build-type: bundle
    - CSP: unset
    - frontendDist: ./ui/dist
    - devUrl: http://localhost:1420/

Stack trace

No response

Additional context

No response