[Tracker] Terminal rendering corruption & visual glitches (stale-issue sweep, July 2026) #5605

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1. Kitenite

   marked OpenCode terminal screen glitch and temporary recovery issue when switching between Superset multi-workspaces #3313 as a duplicate of this issue on Jul 11, 2026
2. github-actions commented on Jul 11, 2026

   

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   on Jul 11, 2026 – with GitHub Actions

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   Automated triage note

   This is a consolidated tracker, not a single reproducible defect — it bundles 26 previously-closed terminal-rendering issues from the July 2026 stale sweep. I walked the desktop terminal rendering + transport subsystem (apps/desktop/src/renderer/lib/terminal/*, .../TabsContent/Terminal/*, apps/desktop/src/main/lib/terminal*) to check whether the cluster shares a single root cause that could be pinned with a bun:test reproduction. It doesn't, and a headless unit test can't exercise any of these — they only manifest against a real Electron renderer with WebGL/Canvas, a running font loader, and live flex layout:

   • GPU / glyph corruption — Terminal renders garbled characters (WebGL texture atlas corruption) #3794 (WebGL texture-atlas), [bug] fonts turning to garbage #2514 (fonts → garbage), [bug] CJK glyph corruption in terminal output (1.9.6) #4639 / [bug] Sometimes the displayed Chinese characters are garbled. #3406 / [Bug] Latin/ASCII characters render as corrupted glyphs when mixed with Chinese text #3570 / [bug] Intermittent garbled text rendering with multiple Claude Code tabs and Chinese content #3572 / [bug] Terminal Output Corruption (Garbled CJK Characters) and Layout Glitches during Heavy Usage #3527 (CJK / mixed-width glyph corruption), [bug] Underline decoration misaligned with CJK/mixed-width text in terminal #2231 (underline vs. wide-char alignment). Depends on the WebGL renderer's glyph atlas and measured font metrics; there is no GPU/Canvas surface in bun test.
   • Repaint / ghosting on focus / workspace / tab switch — [bug] macOS terminal rendering can corrupt and ghost into chat until fullscreen toggle #3504, [bug] Terminal ghosting and accumulating black regions after workspace switches #3351, [bug] Terminal can still repaint into a stale visual state after focus/workspace restore #3321, OpenCode terminal screen glitch and temporary recovery issue when switching between Superset multi-workspaces #3313, [bug] Codex terminal state corrupts on pane reattach after tab/workspace switch #3309, [bug] when focusing back on terminal, content gets corrupted #3208, [bug] Codex output disappears after switching away from Superset and back #2507, [bug] When I switch away from a terminal tab and come back, the input bar appears twice. Additionally, the terminal view is auto-scrolled to the bottom, leaving a large blank space. #1830. xterm viewport repaint plus DOM parking/reattach timing; needs a real renderer and window focus/visibility events.
   • Half-width / wasted horizontal space — Opening Coding Assistant doesn't fill the width of the screen #3482, [bug] opencode doesn't fully fit the terminal #3468, Agentic sessions are using half of availlable space. #3413, [bug] new terminal starts in half width #3281, [bug] TUI rendering broken: content duplication, text cutoff, and wasted horizontal space #3080, Prompt lines duplicate/stack up when resizing window via keyboard shortcut (Cmd+/-) #3179. FitAddon.fit() measuring against an unresolved flex layout or racing a font load; needs real layout + ResizeObserver.
   • Bidi / RTL rendering — [bug] Terminal intermittently renders English text as RTL-looking gibberish #4010. xterm glyph shaping.

   The pure, headless-testable helpers along this path (write-coalescer, the terminal-ws-transport framing, truncateUtf8ToLastBytes, convertLinkRangeToBuffer) are already byte-/boundary-safe and carry regression tests, and the subsystem already ships targeted mitigations for several of these exact reports — e.g. terminal-runtime.ts activates Unicode-11 widths before buffer replay citing #3572, and font-settle.ts, the write-coalescer, and the clipboard/appearance guards address the same families. So the tractable logic layer is already covered; what remains is genuinely renderer/GPU behavior.

   Recommendation: these need an Electron integration/E2E harness (drive the renderer over CDP, per apps/desktop/AGENTS.md) or manual verification on a current build, reproduced per individual issue — not one shared unit test. Per this tracker's own note, anyone still hitting a specific glitch on a current build should comment with the build version and repro steps so the individual issue can be reopened and triaged with the right harness.

   No PR opened — there is no single-root-cause defect to fix or to reproduce headlessly.
3. Kitenite

   marked [bug] When I switch away from a terminal tab and come back, the input bar appears twice. Additionally, the terminal view is auto-scrolled to the bottom, leaving a large blank space. #1830 as a duplicate of this issue on Jul 11, 2026
4. Kitenite

   marked [bug] Underline decoration misaligned with CJK/mixed-width text in terminal #2231 as a duplicate of this issue on Jul 11, 2026
5. Kitenite

   marked [bug] Codex output disappears after switching away from Superset and back #2507 as a duplicate of this issue on Jul 11, 2026
6. Kitenite

   marked [bug] fonts turning to garbage #2514 as a duplicate of this issue on Jul 11, 2026
7. Kitenite

   marked [bug] TUI rendering broken: content duplication, text cutoff, and wasted horizontal space #3080 as a duplicate of this issue on Jul 11, 2026
8. Kitenite

   added

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   on Jul 11, 2026
9. Kitenite

   closed this as duplicateon Jul 11, 2026
10. Kitenite

    marked Prompt lines duplicate/stack up when resizing window via keyboard shortcut (Cmd+/-) #3179 as a duplicate of this issue on Jul 11, 2026
11. Kitenite

    marked [bug] when focusing back on terminal, content gets corrupted #3208 as a duplicate of this issue on Jul 11, 2026
12. Kitenite

    marked [bug] new terminal starts in half width #3281 as a duplicate of this issue on Jul 11, 2026
13. Kitenite

    marked [bug] Codex terminal state corrupts on pane reattach after tab/workspace switch #3309 as a duplicate of this issue on Jul 11, 2026
14. Kitenite

    marked [bug] Terminal can still repaint into a stale visual state after focus/workspace restore #3321 as a duplicate of this issue on Jul 11, 2026
15. Kitenite

    marked [bug] Terminal ghosting and accumulating black regions after workspace switches #3351 as a duplicate of this issue on Jul 11, 2026
16. Kitenite

    marked [bug] Jumbled up output with Claude sessions #3377 as a duplicate of this issue on Jul 11, 2026
17. Kitenite

    marked [bug] Sometimes the displayed Chinese characters are garbled. #3406 as a duplicate of this issue on Jul 11, 2026
18. Kitenite

    marked Agentic sessions are using half of availlable space. #3413 as a duplicate of this issue on Jul 11, 2026
19. Kitenite

    marked [bug] opencode doesn't fully fit the terminal #3468 as a duplicate of this issue on Jul 11, 2026
20. Kitenite

    marked Opening Coding Assistant doesn't fill the width of the screen #3482 as a duplicate of this issue on Jul 11, 2026
21. Kitenite

    marked [bug] macOS terminal rendering can corrupt and ghost into chat until fullscreen toggle #3504 as a duplicate of this issue on Jul 11, 2026
22. Kitenite

    marked [bug] Terminal Output Corruption (Garbled CJK Characters) and Layout Glitches during Heavy Usage #3527 as a duplicate of this issue on Jul 11, 2026
23. Kitenite

    marked [Bug] Latin/ASCII characters render as corrupted glyphs when mixed with Chinese text #3570 as a duplicate of this issue on Jul 11, 2026
24. Kitenite

    marked [bug] Intermittent garbled text rendering with multiple Claude Code tabs and Chinese content #3572 as a duplicate of this issue on Jul 11, 2026
25. Kitenite

    marked [bug] Claude code rendering issue in superset terminal #3668 as a duplicate of this issue on Jul 11, 2026
26. Kitenite

    marked Terminal renders garbled characters (WebGL texture atlas corruption) #3794 as a duplicate of this issue on Jul 11, 2026
27. Kitenite

    marked [bug] Terminal intermittently renders English text as RTL-looking gibberish #4010 as a duplicate of this issue on Jul 11, 2026
28. Kitenite

    marked terminal becomes unreadable #4183 as a duplicate of this issue on Jul 11, 2026
29. Kitenite

    marked [bug] CJK glyph corruption in terminal output (1.9.6) #4639 as a duplicate of this issue on Jul 11, 2026