[iOS] Onscreen keyboard on local side causes graphical issues when connection is closed on remote side #16305

Bug Description

When keyboard input is enabled and the onscreen keyboard is visible on the local (iPhone/iPad) side, closing the connection via the remote device causes graphical issues. These range from visual rubberbanding when keys are pressed, to rapidly flashing images and crashes. Third party keyboards such as Gboard do not fix the issue.

How to Reproduce

1. Establish a connection between an iPhone/iPad to a remote device
2. Enable the onscreen keyboard by pressing the keyboard button (allowing keyboard input if haven't), or by pressing the chat button
3. Close the connection on the remote side by pressing the Disconnect button or by closing the connection window using the X on the top right

Flashing images may then be observed and the application has a high likelihood of crashing. This behaviour is variable per device and may take a few attempts. It is more likely if the keyboard is focused on a text box on the chat menu or on the remote device.

If flashing isn't observed,

4. Observe rubberbanding by pressing keys on the onscreen keyboard

Expected Behavior

When the connection is closed, the onscreen keyboard should exit and a connection error is displayed as usual instead of the erratic behaviour explained above.

Operating system(s) on local (controlling) side and remote (controlled) side

• iOS (27.0)
• iPadOS (16.7.16)
  ⬇️
• Zorin OS 18.1 Core (Linux 7.0.0-31-generic, GNOME 46, Wayland)
• Windows 10 (Virtual Machine, x86-64)
• Linux Mint 22.3 (Virtual Machine, Linux 7.0.0-31-generic, Cinnamon 6.6.9, X11)
• CachyOS (Virtual Machine, Linux 7.2.5-1-cachyos, KDE Plasma 6.7.5, Wayland)

RustDesk Version(s) on local (controlling) side and remote (controlled) side

1.4.9 & 1.5.0 -> 1.4.9 & 1.5.0

Screenshots

[PHOTOSENSITIVE WARNING: Flashing/Rapidly Flashing Images]

Additional Context

iPhone used: iPhone 15
iPad used: iPad Pro (9.7-inch, 1st gen)