From 01279e5fbbfa659e14bb4ad322fd02e4bab3b524 Mon Sep 17 00:00:00 2001
From: edde746 <86283021+edde746@users.noreply.github.com>
Date: Mon, 10 Aug 2026 19:00:50 +0200
Subject: [PATCH] fix(automotive): stop blocking parked playback when the car
 service has no verdict
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CarRestrictionsMonitor.bind() treated a null getCurrentCarUxRestrictions() as
a restricted verdict with supported = true. Dart then latched the restricted
state, every play path refused to start, and on a car that stays parked no
restriction transition ever arrives to correct it — video never played for the
whole session. This is the failure mode behind the Play Automotive rejection of
version code 128 ("unable to play video content"): a review bench whose car
service tracks no restrictions for the resolved display gets exactly that null.

A missing verdict now stays pending instead: Dart keeps lifecycle gating
(parked, foregrounded video plays; while driving the platform blocks the
activity, so DD-2/DD-3 still hold), the registered listener adopts the first
real verdict, and every later getState retries the read. Listener registration
is identity-guarded because retries re-enter bind() with the same cached
manager instance.

Verified on an API 34 Automotive emulator: CarRestrictionsMonitorTest passes on
both connect routes, parked playback starts, driving pauses it behind the OS
blocking screen, and parking again leaves it paused until the user resumes.
---
 .../plezy/car/CarRestrictionsMonitor.kt       | 31 ++++++++++++++++---
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/android/app/src/main/kotlin/com/edde746/plezy/car/CarRestrictionsMonitor.kt b/android/app/src/main/kotlin/com/edde746/plezy/car/CarRestrictionsMonitor.kt
index 81d0038c..1d9f03b3 100644
--- a/android/app/src/main/kotlin/com/edde746/plezy/car/CarRestrictionsMonitor.kt
+++ b/android/app/src/main/kotlin/com/edde746/plezy/car/CarRestrictionsMonitor.kt
@@ -202,14 +202,31 @@ class CarRestrictionsMonitor(
         Log.w(TAG, "Car service is ready but has no UX restrictions manager")
         return
       }
-      manager = uxManager
       // Register before reading, per the platform's own guidance: registration subscribes to future
       // changes only, it does not replay the current one. Reading first would drop a transition that
       // lands between the two binder calls, and publishing the stale "parked" afterwards would then
       // override lifecycle gating and permit audio for the whole drive.
-      uxManager.registerListener { restrictions: CarUxRestrictions -> publish(restrictions.isRequiresDistractionOptimization) }
-      supported = true
-      publish(uxManager.currentCarUxRestrictions?.isRequiresDistractionOptimization ?: true)
+      //
+      // Identity-guarded because a retry re-enters bind() with the same manager instance (Car caches
+      // managers until the service dies): a second registration is at best redundant and at worst a
+      // platform refusal. `manager` is assigned after the listener sticks, so it only ever names a
+      // manager that is actually observing the vehicle.
+      if (manager !== uxManager) {
+        uxManager.registerListener { restrictions: CarUxRestrictions -> adoptVerdict(restrictions.isRequiresDistractionOptimization) }
+        manager = uxManager
+      }
+      val current = uxManager.currentCarUxRestrictions
+      if (current == null) {
+        // The service holds no restrictions for this display (yet). Claiming a verdict here would
+        // publish the restricted default with `supported = true`, and on a car that then stays
+        // parked no transition ever arrives to correct it — playback would refuse to start for the
+        // whole session. Stay pending instead: Dart keeps lifecycle gating (parked, foregrounded
+        // video plays; while driving the platform blocks the activity), the listener above adopts
+        // the first real verdict, and every later getState retries this read.
+        Log.w(TAG, "Car service has no UX restrictions for this display; keeping lifecycle gating until it answers")
+        return
+      }
+      adoptVerdict(current.isRequiresDistractionOptimization)
     } catch (error: Throwable) {
       // Registration is the failure the caller's retry is meant to survive, so keep the connection
       // owned (it is in `car`) and report nothing rather than half-observing the vehicle.
@@ -219,6 +236,12 @@ class CarRestrictionsMonitor(
     }
   }
 
+  /** A real verdict from the vehicle: only now may callers trust [requiresDistractionOptimization]. */
+  private fun adoptVerdict(restricted: Boolean) {
+    supported = true
+    publish(restricted)
+  }
+
   /**
    * Drops a dead car service. The [Car] itself is kept: its `BIND_AUTO_CREATE` binding is what
    * reconnects, and disconnecting would end that for good.