diff --git a/core/java/android/app/Activity.java b/core/java/android/app/Activity.java
index ab03556..65e0b90 100644
--- a/core/java/android/app/Activity.java
+++ b/core/java/android/app/Activity.java
@@ -4719,7 +4719,9 @@
                 resolvedType = fillInIntent.resolveTypeIfNeeded(getContentResolver());
             }
             int result = ActivityManager.getService()
-                .startActivityIntentSender(mMainThread.getApplicationThread(), intent,
+                .startActivityIntentSender(mMainThread.getApplicationThread(),
+                        intent != null ? intent.getTarget() : null,
+                        intent != null ? intent.getWhitelistToken() : null,
                         fillInIntent, resolvedType, mToken, who,
                         requestCode, flagsMask, flagsValues, options);
             if (result == ActivityManager.START_CANCELED) {
diff --git a/core/java/android/app/ContextImpl.java b/core/java/android/app/ContextImpl.java
index 2de205b..268a105b 100644
--- a/core/java/android/app/ContextImpl.java
+++ b/core/java/android/app/ContextImpl.java
@@ -925,7 +925,9 @@
                 resolvedType = fillInIntent.resolveTypeIfNeeded(getContentResolver());
             }
             int result = ActivityManager.getService()
-                .startActivityIntentSender(mMainThread.getApplicationThread(), intent,
+                .startActivityIntentSender(mMainThread.getApplicationThread(),
+                        intent != null ? intent.getTarget() : null,
+                        intent != null ? intent.getWhitelistToken() : null,
                         fillInIntent, resolvedType, null, null,
                         0, flagsMask, flagsValues, options);
             if (result == ActivityManager.START_CANCELED) {
diff --git a/core/java/android/app/IActivityManager.aidl b/core/java/android/app/IActivityManager.aidl
index 9552d17..3ac026d 100644
--- a/core/java/android/app/IActivityManager.aidl
+++ b/core/java/android/app/IActivityManager.aidl
@@ -236,8 +236,8 @@
     Debug.MemoryInfo[] getProcessMemoryInfo(in int[] pids);
     void killApplicationProcess(in String processName, int uid);
     int startActivityIntentSender(in IApplicationThread caller,
-            in IntentSender intent, in Intent fillInIntent, in String resolvedType,
-            in IBinder resultTo, in String resultWho, int requestCode,
+            in IIntentSender target, in IBinder whitelistToken, in Intent fillInIntent,
+            in String resolvedType, in IBinder resultTo, in String resultWho, int requestCode,
             int flagsMask, int flagsValues, in Bundle options);
     void overridePendingTransition(in IBinder token, in String packageName,
             int enterAnim, int exitAnim);
diff --git a/core/java/android/content/IntentSender.java b/core/java/android/content/IntentSender.java
index 0a456b5..ff127df 100644
--- a/core/java/android/content/IntentSender.java
+++ b/core/java/android/content/IntentSender.java
@@ -361,6 +361,11 @@
     }
 
     /** @hide */
+    public IBinder getWhitelistToken() {
+        return mWhitelistToken;
+    }
+
+    /** @hide */
     public IntentSender(IIntentSender target) {
         mTarget = target;
     }
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 54b28d1..bb6637d 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -4587,9 +4587,9 @@
     }
 
     @Override
-    public int startActivityIntentSender(IApplicationThread caller, IntentSender intent,
-            Intent fillInIntent, String resolvedType, IBinder resultTo, String resultWho,
-            int requestCode, int flagsMask, int flagsValues, Bundle bOptions)
+    public int startActivityIntentSender(IApplicationThread caller, IIntentSender target,
+            IBinder whitelistToken, Intent fillInIntent, String resolvedType, IBinder resultTo,
+            String resultWho, int requestCode, int flagsMask, int flagsValues, Bundle bOptions)
             throws TransactionTooLargeException {
         enforceNotIsolatedCaller("startActivityIntentSender");
         // Refuse possible leaked file descriptors
@@ -4597,12 +4597,11 @@
             throw new IllegalArgumentException("File descriptors passed in Intent");
         }
 
-        IIntentSender sender = intent.getTarget();
-        if (!(sender instanceof PendingIntentRecord)) {
+        if (!(target instanceof PendingIntentRecord)) {
             throw new IllegalArgumentException("Bad PendingIntent object");
         }
 
-        PendingIntentRecord pir = (PendingIntentRecord)sender;
+        PendingIntentRecord pir = (PendingIntentRecord)target;
 
         synchronized (this) {
             // If this is coming from the currently resumed activity, it is
@@ -4613,7 +4612,7 @@
                 mAppSwitchesAllowedTime = 0;
             }
         }
-        int ret = pir.sendInner(0, fillInIntent, resolvedType, null, null, null,
+        int ret = pir.sendInner(0, fillInIntent, resolvedType, whitelistToken, null, null,
                 resultTo, resultWho, requestCode, flagsMask, flagsValues, bOptions, null);
         return ret;
     }
diff --git a/services/core/java/com/android/server/notification/NotificationManagerService.java b/services/core/java/com/android/server/notification/NotificationManagerService.java
index 9cd0dff..1ccd171 100644
--- a/services/core/java/com/android/server/notification/NotificationManagerService.java
+++ b/services/core/java/com/android/server/notification/NotificationManagerService.java
@@ -3238,6 +3238,8 @@
             final String noChannelStr = "No Channel found for "
                     + "pkg=" + pkg
                     + ", channelId=" + channelId
+                    + ", id=" + id
+                    + ", tag=" + tag
                     + ", opPkg=" + opPkg
                     + ", callingUid=" + callingUid
                     + ", userId=" + userId
diff --git a/services/core/java/com/android/server/notification/RankingHelper.java b/services/core/java/com/android/server/notification/RankingHelper.java
index f00ef38..55cb2f3 100644
--- a/services/core/java/com/android/server/notification/RankingHelper.java
+++ b/services/core/java/com/android/server/notification/RankingHelper.java
@@ -1115,6 +1115,7 @@
                     Record fullRecord = getRecord(pkg,
                             mPm.getPackageUidAsUser(pkg, changeUserId));
                     if (fullRecord != null) {
+                        createDefaultChannelIfNeeded(fullRecord);
                         deleteDefaultChannelIfNeeded(fullRecord);
                     }
                 } catch (NameNotFoundException e) {}
diff --git a/services/tests/notification/src/com/android/server/notification/RankingHelperTest.java b/services/tests/notification/src/com/android/server/notification/RankingHelperTest.java
index 2c9c114..06b5821 100644
--- a/services/tests/notification/src/com/android/server/notification/RankingHelperTest.java
+++ b/services/tests/notification/src/com/android/server/notification/RankingHelperTest.java
@@ -123,6 +123,7 @@
         when(mPm.getApplicationInfoAsUser(eq(PKG), anyInt(), anyInt())).thenReturn(legacy);
         when(mPm.getApplicationInfoAsUser(eq(UPDATED_PKG), anyInt(), anyInt())).thenReturn(upgrade);
         when(mPm.getPackageUidAsUser(eq(PKG), anyInt())).thenReturn(UID);
+        when(mPm.getPackageUidAsUser(eq(UPDATED_PKG), anyInt())).thenReturn(UID2);
         when(mContext.getResources()).thenReturn(
                 InstrumentationRegistry.getContext().getResources());
         when(mContext.getPackageManager()).thenReturn(mPm);
@@ -1046,6 +1047,24 @@
     }
 
     @Test
+    public void testOnPackageChange_downgradeTargetSdk() throws Exception {
+        // create channel as api 26
+        mHelper.createNotificationChannel(UPDATED_PKG, UID2, getChannel(), true);
+
+        // install new app version targeting 25
+        final ApplicationInfo legacy = new ApplicationInfo();
+        legacy.targetSdkVersion = Build.VERSION_CODES.N_MR1;
+        when(mPm.getApplicationInfoAsUser(eq(UPDATED_PKG), anyInt(), anyInt())).thenReturn(legacy);
+        mHelper.onPackagesChanged(
+                false, UserHandle.USER_SYSTEM, new String[]{UPDATED_PKG}, new int[]{UID2});
+
+        // make sure the default channel was readded
+        //assertEquals(2, mHelper.getNotificationChannels(UPDATED_PKG, UID2, false).getList().size());
+        assertNotNull(mHelper.getNotificationChannel(
+                UPDATED_PKG, UID2, NotificationChannel.DEFAULT_CHANNEL_ID, false));
+    }
+
+    @Test
     public void testRecordDefaults() throws Exception {
         assertEquals(NotificationManager.IMPORTANCE_UNSPECIFIED, mHelper.getImportance(PKG, UID));
         assertEquals(true, mHelper.canShowBadge(PKG, UID));