fix(widget): stop the widget refresh crashing on a null PendingResult

sheaf/app/src/main/java/systems/lupine/sheaf/widget/WidgetRefreshDispatch.kt

@@ -14,10 +14,17 @@ import kotlinx.coroutines.withTimeoutOrNull
 
 private const val TAG = "WidgetRefresh"
 
-// A widget refresh hits the network, so it outlives onUpdate. Without goAsync()
-// the receiver is finished the moment onUpdate returns and the process becomes
-// killable, so the refresh can be cut off mid-request and the widget just stays
-// stale. goAsync() keeps the process alive until finish() is called.
+// A widget refresh hits the network, so it outlives onUpdate. Once the receiver
+// finishes, the process becomes killable and the refresh can be cut off
+// mid-request, leaving the widget stale until the next tick.
+//
+// goAsync() is how a receiver asks to stay alive, but there is only one
+// PendingResult per dispatch and GlanceAppWidgetReceiver.onUpdate claims it for
+// its own compose before any of this runs. So in practice these refreshes are
+// NOT holding the broadcast open, and have not been since this was written.
+// Losing a refresh to process death is a stale widget, not lost data, so this
+// is a known limitation rather than a live bug; the durable fix is to enqueue
+// the refresh as expedited work instead of doing it in the receiver.
 //
 // The broadcast still has a hard deadline (10s in the foreground, 60s in the
 // background) before the system complains, so the work is bounded well inside
@@ -31,7 +38,13 @@ fun BroadcastReceiver.refreshWidgets(
     appWidgetIds: IntArray,
     action: ActionCallback,
 ) {
-    val pending = goAsync()
+    // goAsync() hands out the receiver's PendingResult exactly once and nulls
+    // its own reference, so a second caller in the same dispatch gets null.
+    // GlanceAppWidgetReceiver.onUpdate already calls it for its own compose,
+    // and every caller here runs after super.onUpdate(), so null is the normal
+    // case rather than an edge one. Treating it as non-null threw out of the
+    // finally below and took the process with it.
+    val pending: BroadcastReceiver.PendingResult? = goAsync()
     CoroutineScope(SupervisorJob() + Dispatchers.IO).launch {
         try {
             withTimeoutOrNull(REFRESH_TIMEOUT_MS) {
@@ -44,7 +57,12 @@ fun BroadcastReceiver.refreshWidgets(
         } catch (t: Throwable) {
             Log.w(TAG, "widget refresh failed: ${t::class.simpleName}")
         } finally {
-            pending.finish()
+            // Nothing to release when Glance holds the broadcast; the refresh
+            // still runs, it just isn't protected from the process being
+            // killed. A cut-short refresh leaves the widget stale until the
+            // next tick, which is what happens today anyway.
+            runCatching { pending?.finish() }
+                .onFailure { Log.w(TAG, "could not finish broadcast: ${it::class.simpleName}") }
         }
     }
 }