Terminal reports incorrect background color when queried with OSC 11

[bash]

Tabby version: 1.0.216 (latest)

Description

When querying the terminal for its background color using the OSC 11 sequence it always reports black (^[]11;rgb:0000/0000/0000^[\) instead of the actual background color.

This is an issue especially in light mode as it breaks tools that try to detect dark/light mode based on the terminal's background color.

Some tools that rely on this: delta, run0 (systemd), and bat.

Steps to reproduce

• (Ensure that the config is set to its defaults)
• Enable light mode (Settings -> Color Scheme -> Always Light)
• Run printf '\x1b]11;?\e\\' && cat -v

Observe that the printed color is black instead of white (or a light gray).

Notes

• The foreground color (OSC 10) is reported accurately.
• The issue occurs with both the xterm (WebGL) and the xterm (canvas) frontend.
• From a quick glance: The issue seems to arise from the fact that the background passed to xterm.js (which in turn answers the OSC queries) is sometimes black instead of the actual color:

  tabby/tabby-terminal/src/frontends/xtermFrontend.ts

  Line 373 in 04b34b0

  background: getTerminalBackgroundColor(this.configService, this.themes, scheme) ?? '#00000000',