fix(cli): clamp scrollback box widths + suppress status bar after resize (#25975)

When the terminal shrinks, already-printed box-drawing rules (response,
reasoning, streaming TTS, background-task Panels) reflow into multiple
narrower rows — visible as duplicated horizontal separators / ghost
lines in scrollback. Similarly, prompt_toolkit redraws a fresh status
bar on SIGWINCH on top of one the terminal just reflowed, producing
double-bar artifacts on column shrink.

Two surgical changes:

1. Decorative scrollback boxes now use a new
   `HermesCLI._scrollback_box_width()` helper that clamps to
   `max(32, min(width, 56))`. The live TUI footer is unaffected and still
   uses the full width. Covers: streaming response box (open + close),
   reasoning box (open + close, both streaming and post-stream paths),
   streaming-TTS box close, final-response Rich Panel, and the
   background-task Rich Panel.

2. `_recover_after_resize()` now also sets a new
   `_status_bar_suppressed_after_resize` flag so the dynamic status bar
   and both input separator rules stay hidden until the next user input.
   The flag is cleared in the process loop the moment the user submits
   their next prompt, restoring chrome cleanly.

Tests:
- New `test_input_rules_hide_after_resize_until_next_input` covers the
  flag's effect on rule heights.
- New `test_scrollback_box_width_caps_to_resize_safe_value` covers the
  helper at floor / cap / mid-range / overflow.
- Existing resize-recovery test extended to assert the flag flips.

Refs: #18449 #19280 #22976
Salvage of #24403.

Co-authored-by: Szymonclawd <szymonclawd@mac.home>

cli.py

@@ -2644,6 +2644,12 @@ class HermesCLI:
 
         # Status bar visibility (toggled via /statusbar)
         self._status_bar_visible = True
+        # When True, the input separator rules and the dynamic status bar are
+        # hidden until the next user input. Set by _recover_after_resize() so a
+        # SIGWINCH cannot stamp a freshly-drawn status bar on top of one that
+        # the terminal just reflowed into scrollback — the cause of duplicated
+        # bars / "blank line flooding" reports (#19280, #22976).
+        self._status_bar_suppressed_after_resize = False
         self._resize_recovery_lock = threading.Lock()
         self._resize_recovery_timer = None
         self._resize_recovery_pending = False
@@ -2720,7 +2726,16 @@ class HermesCLI:
         Instead we just reset prompt_toolkit's renderer cache so the next
         incremental redraw starts from a clean slate, then let
         ``original_on_resize`` recalculate layout for the new size.
+
+        We also flag ``_status_bar_suppressed_after_resize`` so the dynamic
+        status bar and input separator rules stay hidden until the next user
+        input.  On column shrink the terminal reflows already-rendered status
+        bar rows into scrollback before prompt_toolkit can erase them; drawing
+        a fresh full-width bar immediately makes the old and new versions
+        look duplicated (#19280, #22976).  Clearing the suppression on the
+        next prompt restores the bar cleanly.
         """
+        self._status_bar_suppressed_after_resize = True
         try:
             app.renderer.reset(leave_alternate_screen=False)
         except Exception:
@@ -2963,10 +2978,34 @@ class HermesCLI:
             width = self._get_tui_terminal_width()
         return width < 64
 
+    @staticmethod
+    def _scrollback_box_width(width: Optional[int] = None) -> int:
+        """Return a resize-safe width for printed scrollback box rules.
+
+        Lines already printed to terminal scrollback are reflowed by the
+        terminal emulator when the column count shrinks. A full-width response
+        border drawn at, say, 200 columns will wrap into two or three rows of
+        dashes after the user resizes to 80 columns, looking like duplicated
+        separator lines (the family of bugs tracked by #18449, #19280, #22976).
+
+        Keep decorative scrollback boxes intentionally narrower than the
+        viewport so a moderate resize never triggers reflow. The live TUI
+        footer (status bar, input rule) still uses the full width — only
+        content that is *stamped into scrollback* needs this clamp.
+        """
+        if width is None:
+            try:
+                width = shutil.get_terminal_size((80, 24)).columns
+            except Exception:
+                width = 80
+        return max(32, min(int(width or 80), 56))
+
     def _tui_input_rule_height(self, position: str, width: Optional[int] = None) -> int:
         """Return the visible height for the top/bottom input separator rules."""
         if position not in {"top", "bottom"}:
             raise ValueError(f"Unknown input rule position: {position}")
+        if getattr(self, "_status_bar_suppressed_after_resize", False):
+            return 0
         if position == "top":
             return 1
         return 0 if self._use_minimal_tui_chrome(width=width) else 1
@@ -3476,7 +3515,7 @@ class HermesCLI:
         # Open reasoning box on first reasoning token
         if not getattr(self, "_reasoning_box_opened", False):
             self._reasoning_box_opened = True
-            w = shutil.get_terminal_size().columns
+            w = self._scrollback_box_width()
             r_label = " Reasoning "
             r_fill = w - 2 - len(r_label)
             _cprint(f"\n{_DIM}┌─{r_label}{'─' * max(r_fill - 1, 0)}┐{_RST}")
@@ -3500,7 +3539,7 @@ class HermesCLI:
             if buf:
                 _cprint(f"{_DIM}{buf}{_RST}")
                 self._reasoning_buf = ""
-            w = shutil.get_terminal_size().columns
+            w = self._scrollback_box_width()
             _cprint(f"{_DIM}└{'─' * (w - 2)}┘{_RST}")
             self._reasoning_box_opened = False
 
@@ -3691,7 +3730,7 @@ class HermesCLI:
                 self._stream_text_ansi = ""
             if self.show_timestamps:
                 label = f"{label} {datetime.now().strftime('%H:%M')}"
-            w = shutil.get_terminal_size().columns
+            w = self._scrollback_box_width()
             fill = w - 2 - HermesCLI._status_bar_display_width(label)
             _cprint(f"\n{_ACCENT}╭─{label}{'─' * max(fill - 1, 0)}╮{_RST}")
 
@@ -3792,7 +3831,7 @@ class HermesCLI:
 
         # Close the response box
         if self._stream_box_opened:
-            w = shutil.get_terminal_size().columns
+            w = self._scrollback_box_width()
             _cprint(f"{_ACCENT}╰{'─' * (w - 2)}╯{_RST}")
 
     def _reset_stream_state(self) -> None:
@@ -7890,6 +7929,7 @@ class HermesCLI:
                         style=_resp_text,
                         box=rich_box.HORIZONTALS,
                         padding=(1, 4),
+                        width=self._scrollback_box_width(),
                     ))
                 else:
                     _cprint("  (No response generated)")
@@ -10549,7 +10589,7 @@ class HermesCLI:
                     nonlocal _streaming_box_opened
                     if not _streaming_box_opened:
                         _streaming_box_opened = True
-                        w = self.console.width
+                        w = self._scrollback_box_width(getattr(self.console, "width", 80))
                         label = " ⚕ Hermes "
                         if self.show_timestamps:
                             label = f"{label}{datetime.now().strftime('%H:%M')} "
@@ -10834,7 +10874,7 @@ class HermesCLI:
             if self.show_reasoning and result and not _reasoning_already_shown:
                 reasoning = result.get("last_reasoning")
                 if reasoning:
-                    w = shutil.get_terminal_size().columns
+                    w = self._scrollback_box_width()
                     r_label = " Reasoning "
                     r_fill = w - 2 - len(r_label)
                     r_top = f"{_DIM}┌─{r_label}{'─' * max(r_fill - 1, 0)}┐{_RST}"
@@ -10865,7 +10905,7 @@ class HermesCLI:
                 already_streamed = self._stream_started and self._stream_box_opened and not is_error_response
                 if use_streaming_tts and _streaming_box_opened and not is_error_response:
                     # Text was already printed sentence-by-sentence; just close the box
-                    w = shutil.get_terminal_size().columns
+                    w = self._scrollback_box_width()
                     _cprint(f"\n{_ACCENT}╰{'─' * (w - 2)}╯{_RST}")
                 elif already_streamed:
                     # Response was already streamed token-by-token with box framing;
@@ -10881,6 +10921,7 @@ class HermesCLI:
                         style=_resp_text,
                         box=rich_box.HORIZONTALS,
                         padding=(1, 4),
+                        width=self._scrollback_box_width(),
                     ))
 
 
@@ -12914,7 +12955,10 @@ class HermesCLI:
                 # guard against any future width mismatch.
                 wrap_lines=False,
             ),
-            filter=Condition(lambda: cli_ref._status_bar_visible),
+            filter=Condition(
+                lambda: cli_ref._status_bar_visible
+                and not getattr(cli_ref, "_status_bar_suppressed_after_resize", False)
+            ),
         )
 
         # Allow wrapper CLIs to register extra keybindings.
@@ -13083,6 +13127,10 @@ class HermesCLI:
                     if not user_input:
                         continue
 
+                    # The user has typed and submitted something, so any
+                    # post-resize transient suppression should end here.
+                    self._status_bar_suppressed_after_resize = False
+
                     # Unpack image payload: (text, [Path, ...]) or plain str
                     submit_images = []
                     if isinstance(user_input, tuple):

scripts/release.py

@@ -71,6 +71,8 @@ AUTHOR_MAP = {
     "kyanam.preetham@gmail.com": "pkyanam",
     "zhizhong.xu@shopee.com": "1000Delta",
     "30397170+1000Delta@users.noreply.github.com": "1000Delta",
+    "szymonclawd@mac.home": "szymonclawd",
+    "257759490+szymonclawd@users.noreply.github.com": "szymonclawd",
     "127238744+teknium1@users.noreply.github.com": "teknium1",
     "147827411+EloquentBrush@users.noreply.github.com": "AhmetArif0",
     "97489706+purzbeats@users.noreply.github.com": "purzbeats",

tests/cli/test_cli_force_redraw.py

@@ -79,6 +79,10 @@ class TestForceFullRedraw:
         SIGWINCH removes it and ``_replay_output_history`` cannot
         reconstruct it.  The fix is to only reset the renderer cache and
         let ``original_on_resize`` recalculate layout.
+
+        Additionally, ``_status_bar_suppressed_after_resize`` must be set
+        so the input rules and status bar hide until the next user input,
+        preventing duplicated-bar artifacts on column shrink (#19280).
         """
         app = MagicMock()
         events = []
@@ -86,6 +90,8 @@ class TestForceFullRedraw:
         app.invalidate.side_effect = lambda: events.append("invalidate")
         original_on_resize = lambda: events.append("original_resize")
 
+        # bare_cli skips __init__, so seed the attribute the way __init__ would.
+        bare_cli._status_bar_suppressed_after_resize = False
         bare_cli._recover_after_resize(app, original_on_resize)
 
         assert events == [
@@ -97,6 +103,8 @@ class TestForceFullRedraw:
         app.renderer.output.erase_screen.assert_not_called()
         app.renderer.output.write_raw.assert_not_called()
         app.renderer.output.cursor_goto.assert_not_called()
+        # Status bar / input rules must be suppressed until the next prompt.
+        assert bare_cli._status_bar_suppressed_after_resize is True
 
     def test_force_redraw_uses_full_screen_clear_without_scrollback_clear(self, bare_cli):
         app = MagicMock()

tests/cli/test_cli_status_bar.py

@@ -332,6 +332,38 @@ class TestCLIStatusBar:
         assert cli_obj._tui_input_rule_height("bottom", width=50) == 0
         assert cli_obj._tui_input_rule_height("bottom", width=90) == 1
 
+    def test_input_rules_hide_after_resize_until_next_input(self):
+        """When _status_bar_suppressed_after_resize is set, both rules hide.
+
+        See _recover_after_resize — column shrink reflows already-rendered
+        bars into scrollback, so we hide the separators until the user
+        submits the next input, at which point the flag is cleared.
+        """
+        cli_obj = _make_cli()
+        cli_obj._status_bar_suppressed_after_resize = True
+
+        assert cli_obj._tui_input_rule_height("top", width=90) == 0
+        assert cli_obj._tui_input_rule_height("bottom", width=90) == 0
+
+        cli_obj._status_bar_suppressed_after_resize = False
+        assert cli_obj._tui_input_rule_height("top", width=90) == 1
+        assert cli_obj._tui_input_rule_height("bottom", width=90) == 1
+
+    def test_scrollback_box_width_caps_to_resize_safe_value(self):
+        """Decorative scrollback boxes clamp to a width small enough that
+        moderate terminal shrinks don't cause reflow into scrollback."""
+        from cli import HermesCLI
+
+        # Floor at 32 — narrow terminals still get something usable.
+        assert HermesCLI._scrollback_box_width(20) == 32
+        assert HermesCLI._scrollback_box_width(32) == 32
+        # Cap at 56 — wide terminals don't get full-width boxes.
+        assert HermesCLI._scrollback_box_width(80) == 56
+        assert HermesCLI._scrollback_box_width(120) == 56
+        assert HermesCLI._scrollback_box_width(200) == 56
+        # Mid-range passes through up to the cap.
+        assert HermesCLI._scrollback_box_width(48) == 48
+
     def test_agent_spacer_reclaimed_on_narrow_terminals(self):
         cli_obj = _make_cli()
         cli_obj._agent_running = True