fix: handle already-joined vault on QR scan instead of hanging by aminsato · Pull Request #4287 · vultisig/vultisig-android

aminsato · 2026-04-26T08:53:43Z

Summary

Fixes #4282 — joining a QR for an existing seed-phrase vault on a device that already has it threw DuplicateVaultException after keygen completed, leaving the Vault created successfully screen stuck on an infinite spinner.

Primary fix — JoinKeygenViewModel (KEYGEN/KeyImport branch) now compares the QR's hexChainCode against existing vaults before doing anything. If a match is found, it skips mediator discovery + keygen entirely and routes to Route.Home(openVaultId = existingVault.id). The non-blank guard prevents matching legacy vaults that have an empty stored chain code.
Defence in depth — KeygenViewModel.saveVault() now catches DuplicateVaultException on the non-override path (only KEYGEN/KeyImport can hit it; reshare/migrate use upsert). On catch it looks up the existing vault by pubKeyECDSA, stops the mediator service, and routes to Home — so the success screen never hangs even if the early hexChainCode check ever misses (e.g. the QR carries an empty chain code, or another flow saved the vault concurrently).
Screen_recording_20260426_050958.webm

Why two layers

The early hexChainCode check is the user-friendly path: skip the whole join when we already know the vault is here. The save-side catch protects the cases the early check can miss — initiating-device flows, blank/legacy chain codes, races against another save — so we never regress to the original infinite spinner.

Test plan

Device A has Vault X (seed-phrase). Device B has the same Vault X stored. Start join keygen flow on B with A's QR — B should land on Home with Vault X selected, no spinner hang, no error toast.
Normal first-time join on a clean device still completes keygen and reaches the backup flow.
Reshare / Migrate flows are unaffected (still upsert; never throw DuplicateVaultException).
Verify on emulator with two debug builds (forward port 18080 + socat per README).

🤖 Generated with Claude Code

Summary by CodeRabbit

Bug Fixes
- Prevented duplicate vault creation when rejoining or importing; users are automatically redirected to their existing vault instead of creating duplicates.
New Features
- UI now detects when a vault is already on the device, showing a localized message with the vault name and a primary action to open the existing vault (navigates to Home and clears back stack).
Localization
- Added localized strings for the new "already on device" message and "open existing vault" action across multiple languages.

Joining a QR for an existing seed-phrase vault on a device that already has it threw DuplicateVaultException after keygen, leaving the success screen stuck on an infinite spinner. Detect the duplicate by hexChainCode in JoinKeygenViewModel and route to the existing vault's Home before keygen starts. As a defence in depth, KeygenViewModel.saveVault now catches DuplicateVaultException on the non-override path and routes to Home so the success screen cannot hang on save failure. Co-Authored-By: aminsato <Amin.saradar@yahoo.com>

coderabbitai · 2026-04-26T08:53:56Z

📝 Walkthrough

Walkthrough

Adds duplicate-vault detection to the keygen join/save flows: JoinKeygenViewModel checks decoded join payload against existing vaults by hexChainCode and short-circuits to an "already joined" UI; KeygenViewModel treats DuplicateVaultException as an existing vault and routes to that vault's home.

Changes

Cohort / File(s)	Summary
ViewModels — duplicate detection & routing `app/src/main/java/com/vultisig/wallet/ui/models/keygen/JoinKeygenViewModel.kt`, `app/src/main/java/com/vultisig/wallet/ui/models/keygen/KeygenViewModel.kt`	Adds `AlreadyJoinedVault` model and `JoinKeygenUiModel.alreadyJoined`; JoinKeygenViewModel detects existing vaults by `hexChainCode`, sets `alreadyJoined` and returns; adds `openExistingVault()` to navigate to existing vault with `clearBackStack`. KeygenViewModel now catches `DuplicateVaultException`, resolves existing vault by `pubKeyECDSA`, stops mediator, and navigates to that vault.
UI — already-joined presentation `app/src/main/java/com/vultisig/wallet/ui/screens/keygen/JoinKeygenScreen.kt`	Prioritizes `state.alreadyJoined` over generic `error`; displays localized "vault already on device" message with vault name and changes primary action to `openExistingVault`.
Localization — new strings across locales `app/src/main/res/values/.../strings.xml` `app/src/main/res/values-de/strings.xml`, `.../values-es/strings.xml`, `.../values-hr/strings.xml`, `.../values-it/strings.xml`, `.../values-ko/strings.xml`, `.../values-nl/strings.xml`, `.../values-pt/strings.xml`, `.../values-ru/strings.xml`, `.../values-zh-rCN/strings.xml`, `.../values/strings.xml`	Adds `join_key_gen_vault_already_on_device` (with `%1$s` vault name placeholder) and `join_key_gen_open_existing_vault` to multiple locale string resources.

Sequence Diagram(s)

sequenceDiagram
    participant UI as JoinKeygenScreen
    participant VM as JoinKeygenViewModel
    participant Repo as VaultRepository
    participant Nav as Navigator
    participant Keygen as KeygenSession/Mediator

    UI->>VM: submit decoded join payload (hexChainCode)
    VM->>Repo: read existingVaults()
    alt matching hexChainCode found
        VM-->>UI: set JoinKeygenUiModel(alreadyJoined)
        UI->>Nav: openExistingVault(vaultId, clearBackStack=true)
    else no match
        VM->>Keygen: start keygen/session
        Keygen->>VM: produce Vault (pubKeyECDSA)
        VM->>Repo: saveVault(vault)
        alt DuplicateVaultException thrown
            VM->>Repo: getByEcdsa(pubKeyECDSA) -> existingVault
            VM->>Keygen: stopMediator()
            VM->>Nav: openExistingVault(existingVault.id, clearBackStack=true)
        else saved successfully
            VM->>Nav: navigate to new vault home
        end
    end

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Poem

🐰
I sniffed the chaincode in the night,
Found a vault already tucked in tight,
No double burrows, one comfy nest—
I point the traveler to the best,
Hop home safe, and sleep in light!

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% 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 accurately summarizes the main change: handling already-joined vaults on QR scan to prevent hanging. It is specific, concise, and directly reflects the primary objective.
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	Check skipped - CodeRabbit’s high-level summary is enabled.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

Create stacked PR
Commit on current branch

🧪 Generate unit tests (beta)

Create PR with unit tests
Commit unit tests in branch aminsato/4282_join_duplicate_vault

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

Replaces the silent redirect with an info screen that names the existing vault and offers an explicit 'Open vault' button, so the user understands what happened. Adds the two new strings (info text and button label) to all 10 supported locales. Co-Authored-By: aminsato <Amin.saradar@yahoo.com>

Co-Authored-By: aminsato <Amin.saradar@yahoo.com>

aminsato · 2026-04-26T10:42:21Z

@codetabbitai full review

johnnyluo

LGTM

aminsato requested review from johnnyluo and rkokhatskyi as code owners April 26, 2026 08:53

aminsato added 2 commits April 26, 2026 05:06

style: apply ktfmt formatting to JoinKeygenViewModel

c7ac944

Co-Authored-By: aminsato <Amin.saradar@yahoo.com>

johnnyluo approved these changes Apr 26, 2026

View reviewed changes

johnnyluo added this pull request to the merge queue Apr 26, 2026

Merged via the queue into main with commit c4106fd Apr 27, 2026
2 checks passed

johnnyluo deleted the aminsato/4282_join_duplicate_vault branch April 27, 2026 00:09

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

fix: handle already-joined vault on QR scan instead of hanging#4287

fix: handle already-joined vault on QR scan instead of hanging#4287
johnnyluo merged 3 commits into
mainfrom
aminsato/4282_join_duplicate_vault

aminsato commented Apr 26, 2026 •

edited

Loading

Uh oh!

coderabbitai Bot commented Apr 26, 2026 •

edited

Loading

Walkthrough

Changes

Sequence Diagram(s)

Estimated code review effort

Poem

❌ Failed checks (1 warning)

Uh oh!

aminsato commented Apr 26, 2026

Uh oh!

johnnyluo left a comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Conversation

aminsato commented Apr 26, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Why two layers

Test plan

Summary by CodeRabbit

Uh oh!

coderabbitai Bot commented Apr 26, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Walkthrough

Changes

Sequence Diagram(s)

Estimated code review effort

Poem

❌ Failed checks (1 warning)

Uh oh!

aminsato commented Apr 26, 2026

Uh oh!

johnnyluo left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

aminsato commented Apr 26, 2026 •

edited

Loading

coderabbitai Bot commented Apr 26, 2026 •

edited

Loading