PR #19983: fix(tui): drop empty submissions left over after stripping leaked terminal bytes

• Repository: NousResearch/hermes-agent
• Author: Tranquil-Flow
• State: open | merged: False
• Link: https://github.com/NousResearch/hermes-agent/pull/19983

Description (problem / solution / changelog)

What does this PR do?

Addresses #19767. WSL2 + Windows Terminal: dragging the window triggers a SIGWINCH storm where prompt_toolkit's DSR (cursor-position) queries and SGR mouse reports leak into stdin. The trailing M of mouse-report sequences parses as Ctrl+M (= Enter), which submits a buffer containing only the leaked bytes — one ghost record per leaked sequence, accumulating to the dozen-plus empty conversation records the reporter screenshots show.

The existing strip helpers (_strip_leaked_bracketed_paste_wrappers, _strip_leaked_terminal_responses_with_meta) already clean those bytes from the submitted buffer, but process_loop did not re-check emptiness afterward, so the empty payload reached _print_user_message_preview and rendered a divider + bullet with no text.

This PR adds the missing post-strip emptiness guard at the existing chokepoint. The fix is a defensive net at the last common point before the preview prints, so it covers any leak path that collapses to empty after stripping — not just the SGR-mouse-as-Ctrl+M mechanism.

Related Issue

Addresses #19767

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)

Changes Made

• cli.py — add _is_empty_after_terminal_noise_strip(text, has_attachments) helper (17 lines) + a guard call in process_loop immediately after the existing strip pass (2 lines + comment). has_attachments is honored so image-only submissions still pass through.
• tests/cli/test_cli_resize_empty_record.py — new regression file:
  • TestEmptyAfterTerminalNoiseStrip (6 cases) — pure-function guard semantics: real text preserved, empty/whitespace dropped, has_attachments=True keeps blank-text payloads alive, non-string inputs handled.
  • TestResizeStormCollapsesToEmpty (6 cases) — drives real leaked CPR / SGR-mouse / bracketed-paste sequences through the same two-step strip pipeline process_loop runs, asserts the guard fires; one positive case proves real text wedged between leaked bytes survives.

How to Test

1. Run pytest tests/cli/test_cli_resize_empty_record.py -q → 12 new tests pass.
2. Adjacent regression check: pytest tests/cli/test_cli_force_redraw.py tests/cli/test_cli_terminal_response_sanitizer.py tests/cli/test_cli_bracketed_paste_sanitizer.py -q → 32 pre-existing pass.
3. Without the source fix, the new test errors at import (the helper doesn't exist) — true regression test.
4. Manual reproduction (WSL2 + Windows Terminal): start hermes, drag the terminal window to resize. Before this PR: dozens of empty bullet records; after: window resizes silently with no transcript change.

Caveat: WSL2-only bug, could not reproduce locally. Diagnosis inferred from prior maintainer comment naming the SGR-mouse-as-Ctrl+M leak path and from reading the existing leak-strip code.

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix
• I've run pytest tests/cli/ -q -k "resize or terminal_response or bracketed_paste" and all tests pass
• I've added tests for my changes
• I've tested on my platform: macOS darwin-arm64 (cannot test WSL2 directly; defensive net at chokepoint)

Documentation & Housekeeping

• I've updated relevant documentation — N/A (helper is internal; behavior matches the existing strip-pipeline contract)
• I've updated cli-config.yaml.example if I added/changed config keys — N/A
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — N/A
• I've considered cross-platform impact (Windows, macOS) — yes, the guard is platform-neutral; WSL2 reporters affected most because their terminal emits the leak under SIGWINCH storms
• I've updated tool descriptions/schemas if I changed tool behavior — N/A

Changed files

• cli.py (modified, +33/-1)
• tests/cli/test_cli_resize_empty_record.py (added, +98/-0)