[t3dotgg]

Dragging a thread from the sidebar into the composer to tag it scrolled the sidebar, often all the way to the bottom.

The path out of the list usually crosses dnd-kit's autoscroll edge zone at the bottom of the sidebar. At that point the drag is still a reorder drag, so dnd-kit autoscrolls fast. Autoscroll turns off once the pointer leaves the list, but the scroll has already happened.

The sidebar now saves its scroll position when a drag starts. It restores that position when the drag leaves the list to become a tag drag, and again on drop. Reordering inside the list still autoscrolls as before.

This works with #27691, which tunes reorder autoscroll (smaller edge zone, slower). That makes tag-drag scroll rarer, but leaving through the edge zone still scrolls. This PR removes the leftover scroll for tag drags. The two PRs change different lines.

Before	After

Sidebar text is pixelated because the test data is real.

Proof: in the web dev app (1280×800, about 500 seeded threads), a slow drag from a low sidebar row to the composer. Measured sidebar scrollTop while hovering the composer: 217px before, 0 after. The tag still lands in the composer. vp run check:changed passes. No automated test was added: no existing harness renders the full sidebar with a long list and drags from it.

Reviewed with sol-loop: 1 pass with GPT-6.1 Sol. Sol verdict: approved

Created with Claude Opus 5.5 in T3 Code (Claude Code harness).

🤖 Generated with Claude Code

[macroscopeapp]

Approvability

Verdict: Approved at d604a91

Macroscope's review found this PR approvable — This preserves the sidebar’s starting scroll position when dragging a thread out of the list for tagging. The change is limited to transient UI state and leaves tagging and persistence behavior unchanged.

No code changes detected at eed671f. Prior analysis still applies.

^{You can add or adjust custom eligibility rules. Learn more.}

[coderabbitai]

No actionable comments were generated in the recent review.

Walkthrough

Thread drags now save the sidebar viewport and its scroll position at drag start. The saved position is restored when a context drag moves or drops outside the thread list. The saved state is cleared when the drag finishes.

Changes: Sidebar drag scroll preservation

Layer / File(s)	Summary
Capture and restore drag scroll position apps/web/src/components/Sidebar.tsx	Thread drag handling captures the sidebar viewport and its scrollTop. It restores that position during moves and drops outside the thread list, then clears the saved state when the drag finishes.

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Possibly related issues

• pingdotgg/t3code#27669: This issue describes unwanted sidebar autoscroll during thread drags, which this change addresses for context drags outside the thread list.

Possibly related PRs

• pingdotgg/t3code#30346: Both changes address sidebar scrolling during thread drags, with this PR restoring the starting position for context drags outside the list.
• pingdotgg/t3code#28038: This PR uses the same context-drag movement and drop handlers that this change updates.
• pingdotgg/t3code#26724: Both changes affect thread context drags to the composer and their sidebar autoscroll behavior.

Suggested labels: bugfix, size:S

Suggested reviewers: maria-rcks

Merge Risk: Minimal · up to d604a

No merge-blocking risk was established from the available review evidence.

Pre-merge checks: 4

Check name	Status	Explanation
Title check		The title clearly identifies the web fix: preventing sidebar scrolling when tagging a thread by drag.
Description check		The description explains the problem, implementation, scope interaction with PR #27691, manual verification, screenshots, and the absence of automated coverage. It does not use the template headings o…
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

Full details: Description check

Explanation

The description explains the problem, implementation, scope interaction with PR #27691, manual verification, screenshots, and the absence of automated coverage. It does not use the template headings or explicitly document approval or an obvious-bug scope exemption, but it is otherwise mostly complete and focused.

Finishing Touches

Generate docstrings

• Commit to this branch
• Create a new PR

Generate unit tests (beta)

• Commit to this branch
• Create a new PR

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

Recent review info

Run configuration

• Source mode: Auto
• Repository: pingdotgg/t3code
• Branch: t3/fix-thread-tag-sidebar-scroll
• File: .coderabbit.config.ts
• Commit: d604a91
• Layers: Repository TS config
• Review profile: CHILL
• Plan: Team
• Run ID: 1c9db710-16a1-4bc4-9e4b-0d1d9cd0a38a

Commits

Reviewing files that changed from the base of the PR and between 202d5b5 and d604a91.

Files selected for processing: 1

• apps/web/src/components/Sidebar.tsx

Included review availability: This review used your included allowance. Your plan provides up to 10 included reviews per hour; 9 remain after this review.