DROID-77263: fix empty-login boot-loop panic in dummybridge

[Fizzadar]

Summary

Fixes a host-app boot-loop crash (DROID-77263) caused by logging into dummybridge with an empty username.

An empty username persisted a UserLogin with ID == "". With split portals enabled (Beeper SDK local bridges), the portal-generation goroutine in DummyClient.Connect built a PortalKey{Receiver: ""}, and Bridge.GetPortalByKey rejected it with receiver must always be set when split portals is enabled. The goroutine's bare panic(err) then crashed the whole SDK process — and the host Android app — on every startup, since the bad login row persists.

This is the approved two-layer fix ("do changes 1+2 only"):

• Change 1 — pkg/connector/login.go: never persist an empty login ID. The login form advertises "anything goes and it's used as the ID", so an empty username is preserved by substituting a random ID rather than being rejected. This prevents an empty receiver at the source.
• Change 2 — pkg/connector/client.go: replace the bare panic(err) in the Connect goroutine with a logged error plus an UNKNOWN_ERROR bridge-state report, then return. Defense in depth — a bad/persistent login error can never crash the host app, including any pre-existing ID == "" logins already in the database.

Testing

• go build ./pkg/connector/... passes; go vet and gofmt clean.

Out of scope

Recovery of already-broken installs / upstream mautrix-go empty-ID validation (Change 3 in the triage plan) is intentionally not included, per the autofix directive.

Linear: https://linear.app/beeper/issue/DROID-77263

🤖 Generated with Claude Code

[linear-code]

DROID-77263

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: ec885f05-cfa8-4554-ba21-5c3430702efc

📥 Commits

Reviewing files that changed from the base of the PR and between f732d6a and 32b981c.

📒 Files selected for processing (2)

• pkg/connector/client.go
• pkg/connector/login.go

📜 Recent review details

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (2)

• GitHub Check: build-docker-dummybridge
• GitHub Check: build-docker-dummybridge

🔇 Additional comments (3)

pkg/connector/login.go (2)

9-9: LGTM!

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152-163: LGTM!

pkg/connector/client.go (1)

120-130: LGTM!

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📝 Walkthrough

Summary by CodeRabbit

• Bug Fixes
  • Connection errors during portal generation are now handled gracefully with detailed error state notifications including specific error codes, instead of causing application crashes
  • Username input validation has been enhanced to automatically sanitize entries and generate valid identifiers when empty values are submitted

Walkthrough

Two defensive fixes in the dummy connector: SubmitUserInput now generates a random dummy-... ID when the submitted username is empty, and Connect's portal-generation goroutine replaces a panic with a logged BridgeState error event followed by a clean return.

Changes

Dummy Connector Defensive Fixes

Layer / File(s)	Summary
Login username fallback generation pkg/connector/login.go	Adds strings import; SubmitUserInput extracts username from input and, when empty, generates a dummy- + random lowercase string ID before passing it to dl.User.NewLogin.
Portal generation error handling in Connect pkg/connector/client.go	Replaces panic(err) in the Connect goroutine with an error log and a BridgeState.Send call carrying StateUnknownError, error code dummy-generate-portal-failed, and the error message, then returns to halt further portal generation.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: fixing an empty-login boot-loop panic in dummybridge, which directly corresponds to the changeset's primary objective.
Description check	✅ Passed	The description is comprehensive and directly related to the changeset, explaining the root cause, the two-layer fix, testing, and out-of-scope items with clear reference to the issue tracker.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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.

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✨ 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 nick/droid-77263-empty-login-panic

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[indent]

PR Summary

Fixes DROID-77263, two related host-app crash paths in dummybridge that fired whenever a login was persisted with an empty UserLogin.ID (e.g. an empty username from the password form). After this PR an empty username is replaced with a random dummy-<id> so split-portal GetPortalByKey(Receiver: "") no longer fails, and the portal-generation goroutine in Connect reports a StateUnknownError bridge state instead of panicing the host process.

• pkg/connector/login.go: substitute "dummy-" + strings.ToLower(random.String(12)) when input["username"] is empty before constructing the UserLogin; non-empty input is unchanged.
• pkg/connector/client.go: replace panic(err) in the post-login portal goroutine with log.Err(...) + BridgeState.Send(StateUnknownError, "dummy-generate-portal-failed", err.Error()) + return; the context.Canceled early-return path is preserved.

Issues

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