TUI re-emits entire conversation history into scrollback on Windows Server (no GPU, over RDP), causing visible "flooding"

What version of Codex CLI is running?

codex-cli 0.147.0 (latest stable as of 2026-08-13)

What platform is your computer?

Windows Server (dual Xeon E5 v4 / Broadwell-EP, no GPU, only BMC 2D display chip),
accessed via RDP. Windows version is older (no Windows Terminal available).

Which terminal emulator are you using?

Reproduced in both:

• ConEmu (Cmder 1.3.25), software GDI rendering
• bare conhost (plain cmd.exe / powershell.exe window)

What issue are you seeing?

During interactive TUI sessions, Codex periodically re-emits the whole prior
conversation into the terminal scrollback — previous messages appear again as
duplicated blocks, flooding the visible area. This happens not only when an
approval/permission dialog appears, but also spontaneously without any dialog
(possibly correlated with console resize events delivered when the RDP session
renegotiates display geometry).

On fast local terminals (e.g. Windows Terminal on a desktop), the same re-emit
presumably happens but is too fast to notice. On this software-rendered,
RDP-transported path, re-printing a long history takes seconds and makes the
TUI nearly unusable.

What steps can reproduce the bug?

1. On a GPU-less Windows Server over RDP, open cmd.exe (bare conhost).
2. Run codex, have a conversation long enough to exceed one screen.
3. Trigger a viewport change (approval prompt) or wait / interact; the previous
   conversation is reprinted into scrollback.

What is the expected behavior?

Finalized history is written to scrollback exactly once. Viewport relayouts
(approval prompts, resizes) should be confined to the active viewport and must
not re-emit historical transcript into the primary scrollback.

What I already tried (none helped)

• tui.alternate_screen = "always" and "never"
• Raw output mode (Alt-R / /raw)
• tui.animations = false, tui.show_tooltips = false
• Fixed terminal window size; tab bar and scrollbar pinned in ConEmu
• Bare conhost (no terminal emulator) — same flooding

Possibly related issues

• #22936 (TUI stores finalized history in real scrollback)
• #30745 (scrollback rows disappear after inline viewport height changes)
• #36995 (TUI scrollback corruption in Windows Terminal)
• #35335 (loses terminal scrollback history after long responses)

Start by reproducing the issue with codex in bare conhost over RDP, then exercise the approval prompt and viewport or resize changes described above. Compare the related issues #22936, #30745, #36995, and #35335 to trace the TUI scrollback and relayout behavior. Done means finalized history appears in scrollback once, while relayouts stay within the active viewport.