[Bug] TUI scroll position resets to session start after approving commands that exceed terminal height #6895

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1. github-actions

   assigned

   kommander

   on Jan 5, 2026
2. github-actions

   added

   opentuiThis relates to changes in v1.0, now that opencode uses opentuiThis relates to changes in v1.0, now that opencode uses opentui

   perfIndicates a performance issue or need for optimizationIndicates a performance issue or need for optimization

   on Jan 5, 2026
3. marcohmann commented on Jan 5, 2026

   

   marcohmann

   on Jan 5, 2026

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   Additional Reproduction Details

   Confirmed Variables

   Terminal-specific: Bug reproduces in WezTerm but not in Alacritty.

   Terminal	TERM value	Bug reproduced?
   WezTerm	xterm-256color	✅ Yes
   Alacritty	alacritty	❌ No

   Both terminals report identical dimensions (tput lines = 24, tput cols = 80).

   Refined Reproduction Steps

   1. Open OpenCode in WezTerm
   2. Have a session with enough content to require scrolling (a few tool calls)
   3. Trigger a bash command where the command text itself is 40+ lines (not just output)
   4. Observe:
      • Approval dialog extends past TUI viewport bottom
      • Cannot scroll within the approval dialog to see full command
      • After pressing Enter, TUI jumps to session start

   Minimal Reproduction Command

   python3 -c "
   # Line 1: Test output for OpenCode command approve bug
   # Line 2 through 42: padding comments...
   # (40+ lines of comments)
   print('done')
   "

   Hypothesis

   The TERM=xterm-256color vs TERM=alacritty difference may cause different terminfo capability handling for:

   • Alternate screen buffer behavior
   • Scroll region handling
   • Viewport dimension queries during modal dialog rendering
4. marcohmann commented on Jan 5, 2026

   

   marcohmann

   on Jan 5, 2026

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   Updated Findings: Two Separate Bugs

   After further testing, this appears to be two distinct issues:

   Bug 1: Dialog overflow (terminal-agnostic)

   The approval dialog extends past the TUI viewport when the command text exceeds terminal height. User cannot scroll within the dialog to see the full command, forcing a blind approve.

   Reproduces in: WezTerm ✅, Alacritty ✅

   Bug 2: Scroll-to-top after approve (WezTerm-specific)

   After approving an oversized command, the TUI scroll position resets to the first message in the session.

   Reproduces in: WezTerm ✅, Alacritty ❌

   Test Matrix

   Session Length	Terminal	Dialog Overflow	Scroll-to-top
   Short	WezTerm	✅	❌
   Long	WezTerm	✅	✅
   Short	Alacritty	✅	❌
   Long	Alacritty	✅	❌

   Root Cause Hypothesis

   1. Dialog overflow: OpenCode doesn't constrain dialog height to viewport or implement internal scrolling for the approval modal.

   2. Scroll-to-top: WezTerm handles alternate screen buffer or scroll region escape sequences differently than Alacritty. The TERM=xterm-256color (WezTerm) vs TERM=alacritty difference may trigger different terminfo code paths.
5. marcohmann commented on Jan 5, 2026

   

   marcohmann

   on Jan 5, 2026

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   Further Testing: GNOME Terminal (Ubuntu default)

   Tested on GNOME Terminal which also uses TERM=xterm-256color like WezTerm.

   Results

   • Dialog overflow: ✅ Yes (same as all terminals)
   • Scroll-to-top: ❌ No

   Updated Test Matrix

   Terminal	TERM	Dialog Overflow	Scroll-to-top
   WezTerm	xterm-256color	✅	✅
   GNOME Terminal	xterm-256color	✅	❌
   Alacritty	alacritty	✅	❌

   Conclusion

   The scroll-to-top bug is WezTerm-specific, not related to the TERM value. Both GNOME Terminal and WezTerm use xterm-256color but only WezTerm exhibits the scroll reset behavior.

   This points to something specific in WezTerm's:

   • Alternate screen buffer handling
   • Scroll region escape sequence interpretation
   • Or how it handles the TUI framework's viewport management
6. marcohmann commented on Jan 5, 2026

   

   marcohmann

   on Jan 5, 2026

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   Correction: Scroll-to-top reproduces in Alacritty with longer sessions

   With a sufficiently long session, the scroll-to-top bug does reproduce in Alacritty.

   Updated Understanding

   The scroll-to-top is not terminal-specific - it's an OpenCode bug that triggers based on session length. WezTerm just has a lower threshold to trigger it.

   Terminal	Dialog Overflow	Scroll-to-top (short session)	Scroll-to-top (long session)
   WezTerm	✅	✅ (triggers earlier)	✅
   GNOME Terminal	✅	❌	Not yet tested
   Alacritty	✅	❌	✅

   Root Cause Hypothesis (revised)

   Both bugs are likely OpenCode core issues:

   1. Dialog overflow: No height constraint or internal scroll for approval modal
   2. Scroll-to-top: Viewport/scroll position not preserved after dismissing oversized modal - severity varies by terminal but fundamentally an OpenCode issue

   WezTerm may just be more sensitive to whatever scroll position handling OpenCode is doing.
7. github-actions commented on Mar 25, 2026

   

   github-actionsBot

   on Mar 25, 2026 – with GitHub Actions

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   To stay organized issues are automatically closed after 90 days of no activity. If the issue is still relevant please open a new one.
8. excess122 commented on Apr 20, 2026

   

   excess122

   on Apr 20, 2026

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   I can reproduce this on Windows as well.

   Environment:

   • OS: Windows 11 24H2
   • OpenCode: v1.14.19 (installed via Scoop)
   • Terminal: Windows Terminal 1.22
   • Shell: PowerShell 5.1

   Reproduction steps:

   1. Start opencode in any project directory
   2. Send a prompt that produces a long response (e.g. ask it to explain a large file)
   3. Try scrolling up with mouse wheel or keyboard — the viewport jumps erratically or fails to scroll to the top

   Observed behavior:

   • Scroll position jumps unpredictably, sometimes snapping back to bottom
   • Cannot reliably scroll to review earlier parts of a long conversation
   • Mouse wheel scroll and keyboard scroll both affected

   This appears to be the same viewport/scroll issue described in the original report, confirmed on Windows.
9. thdxr

   removed

   opentuiThis relates to changes in v1.0, now that opencode uses opentuiThis relates to changes in v1.0, now that opencode uses opentui

   perfIndicates a performance issue or need for optimizationIndicates a performance issue or need for optimization

   on May 3, 2026
10. rekram1-node

    closed this as not plannedon May 22, 2026