[flamboh]

Note

🤖 Claude Opus 5.5 on behalf of Oliver

Problem

On iOS, switching between Overview, Guide and Activity on a pull request jumps the page. From the top, the content moves up by the header's height and the PR title ends up under the navigation bar. This regressed in #24284, which let UIKit own the lists' top inset (contentInsetAdjustmentBehavior="automatic") in place of an explicit contentInset.

The bug is in this screen, not in the shared SegmentedControl. Each tab is its own list with its own copy of the header, and selectSection scrolls the next list to the current offset before showing it. Two clamps break that scroll:

• React Native's iOS scrollTo clamps the target to -contentInset.top. It reads the raw inset, which is 0 under automatic adjustment, so the resting offset (-82 on the test device) became 0.
• LegendList clamps to the size of its measured rows. That size leaves out the minHeight that lets a short tab (Guide, a quiet Activity) keep a collapsed header. A partly scrolled header on Overview snapped back on those tabs. This one also happens on Android.

On Android the offset math was also off. Android lists start below the header and get no automatic insets, but the screen still subtracted the safe-area insets. headerEnd came out 50pt early, short tabs could only scroll to 138 of the 212 they needed, and the files button stopped 50pt short of Changed files. Switching tabs while the switcher sat at the top edge dropped the page by about 45pt.

Fix

• Enable scrollToOverflowEnabled on the tab lists, the same fix ThreadFeed uses for this RN clamp.
• Have selectSection scroll the native scroll view directly instead of going through LegendList's scrollToOffset. LegendList picks up the new offset from the scroll event.
• Use the bar insets in the list offset math on iOS only. Android uses 0.

Evidence

Android (Pixel 8 emulator): Overview scrolled partway, then Guide, then back.

Before (main):

https://gh-file-drop-api-prod-galwoqjslzlnws6s.oliver-boorstein.workers.dev/f/e41629d0a573ccc9/android-before.mp4

After:

https://gh-file-drop-api-prod-galwoqjslzlnws6s.oliver-boorstein.workers.dev/f/57e7d2d09ad24de1/android-after.mp4

iOS (T3 Duo, iOS 27.1): tap Activity at the top, tap Overview, scroll until the switcher is pinned under the bar, then tap Activity.

Before (main):

https://gh-file-drop-api-prod-galwoqjslzlnws6s.oliver-boorstein.workers.dev/f/f2bf41bcf5d24ca1/pr-tab-jump-before.mp4

After:

https://gh-file-drop-api-prod-galwoqjslzlnws6s.oliver-boorstein.workers.dev/f/fad8a425587c0534/pr-tab-jump-after.mp4

Edge cases checked

I logged contentOffset before and after each switch on both platforms (Android, iOS):

• Top, every tab pair: stays at 0 / -82. On Android, main never had the top-of-page jump.
• Partly collapsed header to a short tab: Overview 110.9 / 87 keeps the same offset on Guide and Activity and back. On main, Android Guide snapped to 0.
• Switcher at the top edge: Overview 177.1 / 116.7 keeps it on Activity and Guide. Before the Android fix, Android landed at 137.9.
• Short tab range: flinging Guide stops at 212.2 / 154.7, exactly the header end, with no blank space past the content.
• Round trip: Overview 153.5 / 69.7, then Activity, then back, returns to the same offset. If Activity is scrolled up first (7.6 / -71.7), Overview follows it, as designed.
• Activity filter shrinks the list: Activity at 175 with bot comments shown (iOS) clamps to 154.7 when they're hidden. The next switch reads 154.7, so no stale saved offset.
• Files button from Activity or Guide: Overview restores to the header end, then lands on Changed files (1011.4 on Android, which used to stop 50pt short at 961.1).

You can only tap the switcher while some of the header is showing. So restoring a tab's own saved offset past the header only runs through the files button.

No unit test: the bugs are in the native and LegendList scroll clamps and in the inset values passed to pullRequestTabOffset, not in its logic. vp run check:changed passes.

Made with Claude Opus 5.5 in Claude Code (T3 Code).

[macroscopeapp]

Approvability

Verdict: Approved at 6efe201

Macroscope's review found this PR approvable — Preserves scroll position when switching mobile pull-request tabs and aligns inset calculations with each platform. The change is limited to screen layout and scrolling, with no persistent-data or product-default changes.

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[coderabbitai]

Walkthrough

Pull-request tab scrolling now uses platform-adjusted bar insets for offsets, jumps, and short-tab minimum height. Tab switching uses the native scroll ref, and the list enables scrolling beyond the normal inset clamp.

Changes: Pull request section scrolling

Layer / File(s)	Summary
Adjusted insets and native scrolling apps/mobile/src/features/pull-requests/PullRequestRouteScreen.tsx	iOS uses safe-area insets, while Android uses zero insets. Tab offsets, file and description jumps, and short-tab minimum height use the adjusted insets. Tab switching uses the native scroll ref, and the list enables scrollToOverflowEnabled.

Priority: Low

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

Change: Bug fix

Possibly related PRs

• pingdotgg/t3code#24284: Updates automatic iOS content-inset behavior in the same screen.
• pingdotgg/t3code#24826: Changes tab selection and offset tracking in the same screen.
• pingdotgg/t3code#25525: Retains per-tab offsets and changes the file-jump path in the same screen.

Suggested labels: bugfix

Suggested reviewers: juliusmarminge

Merge Risk: Low · up to 6efe2

Short pull-request tabs may scroll into a small blank area on Android; restore the bottom-inset adjustment before merging.

Pre-merge checks: 3 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Description check		The description covers the required template sections in substance. Problem is stated with expected behavior, reproduction steps, and environment (iOS and Android, test devices, the regression from #2…	Add a 'Scope and approval' section. Link the triaged bug issue or the discussion with explicit maintainer approval of direction and scope, including the approval comment. If no prior issue exists, explain why this focused fix of an obvious …

Passed checks: 3 passed

Check name	Status	Explanation
Title check		The title follows conventional commit form and names the main change: switching pull request tabs on mobile no longer makes the page jump. It matches the described fix (enabling scrollToOverflowEnable…
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: Title check

Explanation

The title follows conventional commit form and names the main change: switching pull request tabs on mobile no longer makes the page jump. It matches the described fix (enabling scrollToOverflowEnabled and scrolling the native scroll view in selectSection) in PullRequestRouteScreen.tsx. It is specific and not vague.

Full details: Description check

Explanation

The description covers the required template sections in substance. Problem is stated with expected behavior, reproduction steps, and environment (iOS and Android, test devices, the regression from #24284). Change explains the fix in three bullets and why each applies to both platforms. Verification is detailed: before/after videos on Android and iOS, logged contentOffset values for multiple edge cases, and a note that no unit test was added with reasons, plus vp run check:changed passing. Gaps: the Scope and approval section is missing. It has no linked triaged issue or maintainer-approved discussion, and no explanation for why a small fix qualifies without one. The template asks for that. The Problem section also refers to #24284 without stating the linked issue. The description is otherwise thorough.

Resolution

Add a 'Scope and approval' section. Link the triaged bug issue or the discussion with explicit maintainer approval of direction and scope, including the approval comment. If no prior issue exists, explain why this focused fix of an obvious bug qualifies for an exemption. The scope explanation should state why the changes to the tab lists, selectSection, and the inset math stay within the bug fix. Keep the existing Problem, Change, Verification, and evidence content.

Finishing Touches

🧪 Generate unit tests (beta)

• Create a new PR

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Dismissing prior approval to re-evaluate 6efe201

[coderabbitai]

Actionable comments posted: 1

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• 🪄 Fix comments: Fix CodeRabbit comments on this PR

Prompt to fix review comments

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only still-valid issues, skip the rest with a brief reason, keep changes
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Inline comments:
Review comments at
@apps/mobile/src/features/pull-requests/PullRequestRouteScreen.tsx:
- Around line 710-716: Update the short-tab minHeight calculation in
PullRequestRouteScreen so Android subtracts the bottom inset included by the
overlaid PullRequestActionToolbar, while other platforms continue subtracting
barInsets.bottom.

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Review info

Run configuration

• Source mode: Auto
• Repository: pingdotgg/t3code
• Branch: main
• File: .coderabbit.config.ts
• Commit: d0b81ce
• Layers: Repository TS config
• Review profile: CHILL
• Plan: Advanced
• Run ID: 5493475b-9b5c-477b-aac4-81d6927b153f

Commits

Reviewing files that changed from the base of the PR and between 56e952c and 6efe201.

Files selected for processing: 1

• apps/mobile/src/features/pull-requests/PullRequestRouteScreen.tsx

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