Previous output/prompt gobbled when scrolled up in VS Code terminal

[st0012]

Description

When using Reline in VS Code terminal, if the user scrolls up to see previous output, some of them would be gobbled.

Examples

In this IRB example, some previous prompts and "parts" of the if condition disappeared when scrolling up:

Screen.Recording.2023-07-21.at.15.12.11.mov

Similar issues happen with Reline's bin/example as well. You can see the previous echoed values disappeared.

Screen.Recording.2023-07-21.at.15.18.37.mov

Terminal Emulator

I tested the above examples with ZSH in both iTerm2 and VS Code terminal, and the problem only happens in VS Code Terminal.

(Edit: it also happens when using bash in VS Code terminal)