[Lldb-commits] [lldb] [lldb] Recompute the statusline on resize without clearing the screen (PR #202691)

[Jonas Devlieghere via lldb-commits]

JDevlieghere wrote:

> Not sure what's the problem, but the lldb prompt ends up drawn inside the status line when reducing the window height. It doesn't happen always (I think it depends on the position of the prompt and how fast I resize the window), but I can reliably reproduce it when the cursor is at the bottom of the scroll window, and I reduce the height by one:
>
> FWIW, this is xfce4-terminal 1.2.0

I don't have access to an interactive Linux environment, but I'll try to set something up today. In the meantime, I have some theories:

1. Editline gets its own window dimensions with `EL_GETTC`. I'm not sure what the technical motivation for that was, but I can see a potential discrepancy between what was reported from the signal handler thread in the driver and what the actual terminal dimensions are at the time we try to redraw the prompt.
2. Related to the former, after we adjust the scroll window, we rely on the terminal's native scrolling behavior to take of scrolling up, but the actual terminal dimensions don't change. I can imagine that there's a computation somewhere that should account for that. 

I think eliminating (1) would be beneficial regardless of whether it's part of the issue here, so I'll start by looking into that.

https://github.com/llvm/llvm-project/pull/202691