Fix: Adding custom games from USB OTG drives silently fails

[sam1am]

Description

Adding a custom game from a USB OTG drive silently failed: getPathFromTreeUri hardcodes /storage/<uuid> when converting the picked document tree to a file path, but USB OTG drives on some devices (verified on a Samsung Galaxy Z Fold6, Android 16) are only mounted at the path reported by StorageVolume.getDirectory() — e.g. /mnt/media_rw/<uuid> — with no /storage/<uuid> view at all. The resolved path never existed (stat → ENOENT), so CustomGameScanner.createLibraryItemFromFolder rejected the folder even with All files access granted.

The fix resolves the volume root via StorageManager by matching the volume UUID from the tree document ID, preferring /storage/<uuid> when it exists (SD cards) and falling back to StorageVolume.getDirectory() (USB OTG). Verified end-to-end on the affected device: a GOG game folder on a USB drive now adds and shows up in the library.

Diagnostics captured during testing on the affected device:

path: /storage/6A1F-93F0/Games/GOG/Blood West
Os.stat errno=2 (ENOENT)
isExternalStorageManager=true
volume uuid=6A1F-93F0 state=mounted removable=true primary=false dir=/mnt/media_rw/6A1F-93F0 desc=SANZANG

Two adjacent pre-existing issues noticed while debugging (not addressed here, happy to file separately):

• On the modern flavor, the custom-game flow forwards users to the system All files access page, but the toggle there is permanently greyed out since the flavor doesn't declare MANAGE_EXTERNAL_STORAGE — a dead end. Only legacy can complete this flow.
• When the selected folder fails validation, LibraryViewModel.addCustomGameFolder only logs and returns — the user gets no feedback.

Recording

https://www.youtube.com/shorts/mAWQXeKYIus

Type of Change

• Bug fix
• Performance / stability improvement
• Compatibility improvements
• Other (requires prior approval)

Checklist

• If I have access to #code-changes, I have discussed this change there and it has been green-lighted. If I do not have access, I have still provided clear context in this PR. If I skip both, I accept that this change may face delays in review, may not be reviewed at all, or may be closed.
• This change aligns with the current project scope (core functionality, stability, or performance). If not, it has been explicitly approved beforehand.
• I have attached a recording of the change.
• I have read and agree to the contribution guidelines in CONTRIBUTING.md.

🤖 Generated with Claude Code

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Summary by cubic

Fixes custom-game folder import from USB OTG drives by resolving the correct storage volume root instead of hardcoding /storage/<uuid>. Users can now add games from OTG drives mounted only under /mnt/media_rw/<uuid> (e.g., Samsung devices).

• Bug Fixes

  • Resolve volume root via StorageManager by matching the volume UUID; prefer /storage/<uuid> if it exists, else use StorageVolume.getDirectory(), then append the picked path.
  • Update getPathFromTreeUri to accept Context and pass it from the folder picker.

• Refactors

  • Extract volume root resolution into a documented resolveVolumeRoot helper.

^{Written for commit 5b449e3. Summary will update on new commits.}

Summary by CodeRabbit

• Bug Fixes
  • Improved reliability of the custom game folder picker when accessing folders on secondary or non-primary storage volumes.
  • Better handling of various device storage layouts to reduce failed folder selections and improve path resolution across Android devices.

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR changes getPathFromTreeUri to accept an Android Context and resolve non-primary volume mount roots using StorageManager (falling back to /storage/ when present). The rememberCustomGameFolderPicker call site is updated to pass LocalContext.current.

Changes

Storage Volume Path Resolution

Layer / File(s)	Summary
Resolve volume root helper app/src/main/java/app/gamenative/ui/components/CustomGameFolderPicker.kt	Adds resolveVolumeRoot(context, volumeId) which prefers /storage/<volumeId> when present and otherwise queries StorageManager for the volume mount root.
API signature and path construction app/src/main/java/app/gamenative/ui/components/CustomGameFolderPicker.kt	getPathFromTreeUri signature changed to getPathFromTreeUri(context, uri). Implementation now calls resolveVolumeRoot(context, volumeId) and returns volumeRoot combined with the document-relative path; old existence checks for /storage/<volumeId> candidates were removed.
Call site update app/src/main/java/app/gamenative/ui/components/CustomGameFolderPicker.kt	rememberCustomGameFolderPicker updated to pass LocalContext.current into the new getPathFromTreeUri(context, uri) call.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

A rabbit hops with context bright,
Storage volumes now in sight.
No more guessing, paths ring true,
StorageManager knows what to do! 🐰📱

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically summarizes the main bug being fixed: adding custom games from USB OTG drives now works instead of silently failing.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description check	✅ Passed	The pull request provides a comprehensive description covering the bug, root cause, solution, device testing, and a video demonstration.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[cubic-dev-ai]

No issues found across 1 file

_{Re-trigger cubic}