fix: don't skip receiver frame cryptor when track metadata arrives late (+ sync upstream, drop fork-only changes)

[td-famedly]

Problem

A remote track can be subscribed before its TrackInfo metadata (mimeType / encryption) has been applied to the publication. The TrackSubscribedEvent handler in E2EEManager decided on that incomplete metadata:

• mimeType.split('/')[1] threw a RangeError on an empty mime type, killing the handler.
• An unset encryption read as kNone, so the frame cryptor was skipped.

Either way no frame cryptor was ever created for the track, so with insertable streams enabled the frames stayed encrypted forever — black video / silent audio that only a renegotiation (e.g. toggling a screenshare) could unstick.

Changes

E2EE fix (lib/src/e2ee/e2ee_manager.dart):

• Wait (bounded by connectOptions.timeouts.publish) for the publication's TrackInfo (latestInfo) / mimeType to be populated before deciding whether a frame cryptor is needed, and abort cleanly when the track is unsubscribed or replaced while waiting. Confirmed-unencrypted tracks exit the wait immediately (Bugbot finding).
• Parse the codec from the mime type safely instead of throwing on malformed values, and still create the cryptor (without updateCodec) if the mime type never arrives for an encrypted track.
• Attach onFrameCryptorStateChanged right after creating a cryptor (before updateCodec) so E2EE state changes are always surfaced.
• Wrap both cryptor setup paths in try/catch with a warning log so failures are visible instead of silently dropped.
• Expose the frame / data-packet cryptor factories as @visibleForTesting fields so tests can inject fakes instead of hitting platform channels.

Regression tests (test/e2ee/e2ee_manager_test.dart):

• Encrypted track subscribed before its metadata arrives → frame cryptor is created once the metadata is applied, and cryptor state changes surface as TrackE2EEStateEvent.
• Encrypted track whose mimeType never arrives → frame cryptor is still created after the publish timeout.
• Confirmed-unencrypted track → cryptor setup is skipped promptly instead of polling until the publish timeout.

All three were verified to fail against the pre-fix handler (RangeError on the first two, delayed-skip timeout on the third). Test infra: fake FrameCryptor / DataPacketCryptor factories, media stream fakes from room_e2e_test moved to a shared mock (plus a fake RTCRtpReceiver), and E2EContainer accepts custom ConnectOptions.

Removed fork-only changes (separate commit):

• Restored lib/src/core/room.dart and lib/src/track/web/_audio_html.dart to their upstream (livekit/client-sdk-flutter) versions, dropping the [audioElementLogs] debug logging and the 5×1s retry loop for _getRemoteParticipantBySid. That retry loop delayed media track event handling and made the room_e2e_test "tracks arriving before participant metadata" test time out.

The branch is rebased onto the fork's main (which now includes upstream's "Certificate pinning (livekit#1065)"), so after this PR the fork differs from upstream main only by the E2EE fix and its tests.

Verification

• dart format . --set-exit-if-changed — no changes.
• dart run import_sorter:main --no-comments --exit-if-changed — no changes.
• dart run scripts/check_version.dart — all version checks passed.
• flutter analyze — no issues.
• flutter test — all 344 tests pass (341 + the 3 new E2EE regression tests).

  

[cursor]

Cursor Bugbot has reviewed your changes using high effort and found 1 potential issue.

Bugbot Autofix prepared a fix for the issue found in the latest run.

• ✅ Fixed: Unencrypted remote tracks wait publish timeout
  • Changed the wait-loop condition from encryptionType == kNone (which is also true for confirmed-unencrypted tracks) to latestInfo == null, so plaintext remotes with a valid mimeType exit the loop immediately instead of polling until the publish timeout.

Or push these changes by commenting:

@cursor push af34777981

Preview (af34777981)

diff --git a/lib/src/e2ee/e2ee_manager.dart b/lib/src/e2ee/e2ee_manager.dart
--- a/lib/src/e2ee/e2ee_manager.dart
+++ b/lib/src/e2ee/e2ee_manager.dart
@@ -132,7 +132,7 @@
     final timeout = participant.room.connectOptions.timeouts.publish;
     final deadline = DateTime.now().add(timeout);
     var codec = _codecFromMimeType(publication.mimeType);
-    while ((codec.isEmpty || publication.encryptionType == EncryptionType.kNone) && DateTime.now().isBefore(deadline)) {
+    while ((codec.isEmpty || publication.latestInfo == null) && DateTime.now().isBefore(deadline)) {
       await Future.delayed(const Duration(milliseconds: 200));
       // Manager was cleaned up, or the track was unsubscribed / replaced while
       // waiting; a newer subscription will run its own setup.

_{You can send follow-ups to the cloud agent here.}

^{Reviewed by Cursor Bugbot for commit e52bdb8. Configure here.}

[cursor]

Unencrypted remote tracks wait publish timeout

Medium Severity

The remote frame-cryptor wait loop keeps running while publication.encryptionType == EncryptionType.kNone, but that value also means a confirmed unencrypted track once TrackInfo is applied. Plaintext remotes with a valid mimeType therefore poll until connectOptions.timeouts.publish (often 10s) before the handler can skip setup, delaying every such subscribe in E2EE-enabled rooms.

 

^{Reviewed by Cursor Bugbot for commit e52bdb8. Configure here.}

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