Fallback to default display if initial one is detached

Test: presubmit
Fixes: 285630617
Change-Id: I196bab294c182230edda54241f7b725f44f05570

core/java/android/window/WindowProviderService.java

@@ -34,6 +34,7 @@ import android.content.res.Configuration;
 import android.hardware.display.DisplayManager;
 import android.os.Bundle;
 import android.os.IBinder;
+import android.util.Log;
 import android.view.Display;
 import android.view.WindowManager;
 import android.view.WindowManager.LayoutParams.WindowType;
@@ -52,6 +53,8 @@ import android.view.WindowManagerImpl;
 @UiContext
 public abstract class WindowProviderService extends Service implements WindowProvider {
 
+    private static final String TAG = WindowProviderService.class.getSimpleName();
+
     private final Bundle mOptions;
     private final WindowTokenClient mWindowToken = new WindowTokenClient();
     private final WindowContextController mController = new WindowContextController(mWindowToken);
@@ -194,8 +197,16 @@ public abstract class WindowProviderService extends Service implements WindowPro
     public final Context createServiceBaseContext(ActivityThread mainThread,
             LoadedApk packageInfo) {
         final Context context = super.createServiceBaseContext(mainThread, packageInfo);
-        final Display display = context.getSystemService(DisplayManager.class)
-                .getDisplay(getInitialDisplayId());
+        final DisplayManager displayManager = context.getSystemService(DisplayManager.class);
+        final int initialDisplayId = getInitialDisplayId();
+        Display display = displayManager.getDisplay(initialDisplayId);
+        // Fallback to use the default display if the initial display to start WindowProviderService
+        // is detached.
+        if (display == null) {
+            Log.e(TAG, "Display with id " + initialDisplayId + " not found, falling back to "
+                    + "DEFAULT_DISPLAY");
+            display = displayManager.getDisplay(DEFAULT_DISPLAY);
+        }
         return context.createTokenContext(mWindowToken, display);
     }